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**Provisional chapter**

### **Cardiopulmonary Resuscitation in Special Circumstances Circumstances**

**Cardiopulmonary Resuscitation in Special** 

DOI: 10.5772/intechopen.70304

Diana Carmen Cimpoesu and Tudor Ovidiu Popa

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.70304

Diana Carmen Cimpoesu and

### **Abstract**

Tudor Ovidiu Popa

Cardiopulmonary resuscitation (CPR) in special circumstances includes the emergency intervention for special causes, special environments and special patients. Special causes cover the potential reversible causes of cardiac arrest that must be identified or excluded during any resuscitation, divided into two groups, 4Hs and 4Ts: hypoxia, hypo-/hyperkalaemia and other electrolyte disorders, hypo-/hyperthermia, hypervolemia, tension pneumothorax, tamponade (cardiac), thrombosis (coronary or pulmonary) and toxins. The special environments section includes recommendations for the treatment of cardiac arrest occurring in specific locations: cardiac surgery, catheterisation laboratory, dialysis unit, dental surgery, commercial airplanes or air ambulances, field of play, difficult environment (e.g. drowning, high altitude, avalanche and electrical injuries) or mass casualty incident. CPR for special patients gives guidance for the patients with severe comorbidities (asthma, heart failure with ventricular assist devices, neurological disease and obesity) and pregnancy women or elderly people.

**Keywords:** cardiopulmonary resuscitation, special causes, special patients, special environment

### **1. Introduction**

According to the actual guidelines for cardiopulmonary resuscitation (CPR), early recognition and calling for help, early defibrillation, high-quality resuscitation with minimal interruption of chest compressions and treatment of reversible causes are the most important interventions that can improve the outcomes after cardiac arrest [1–4].

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

The 2015 Guidelines for resuscitation published by European Resuscitation Council divide the resuscitation in special circumstances into three parts: special causes, special environments and special patients [4].

The first part covers treatment of potentially reversible causes of cardiac arrest, for which specific treatment exists and which are divided into two groups of four, called 'the 4Hs and 4Ts': hypoxia; hypo-/hyperkalaemia and other electrolyte disorders; hypo-/hyperthermia; hypovolaemia; tension pneumothorax; tamponade (cardiac tamponade); thrombosis (coronary and pulmonary) and toxins (poisoning) [1, 4].

The second part covers cardiac arrest in special environments, where universal guidelines should be modified due to specific locations or location-specific causes of cardiac arrest [1, 5].

The third part contains the recommendation for the patients with specific conditions and those with certain long-term comorbidities, where a modified approach and different treatment decisions may be necessary [4].

### **2. Special causes**

**Hypoxia** is usually a consequence of asphyxia, which is defined as pathological changes caused by lack of oxygen in respired air, resulting in a deficiency of oxygen in the blood (hypoxia) and an increase in carbon dioxide in the blood and tissues (hypercapnia). Symptoms usually include irregular and disturbed respirations, or a complete absence of breathing, and pallor or cyanosis. Asphyxia may occur whenever there is an interruption in the normal exchange of oxygen and carbon dioxide between the lungs and the outside air. Some common causes are drowning, electric shock, hanging, suffocation, lodging of a foreign body in the air passages, inhalation of smoke and poisonous gases, and trauma to or disease of the lungs or air passages. Hypoxia requires ventilation with airway adjuncts that need to be verified to be placed correctly. There is necessary to check breath sounds at regular time intervals to ensure that the endotracheal tube has not slipped out of the trachea or to identify the presence of pneumothorax. Also is necessary to verify the source of oxygen (an oxygen cylinder or the piped oxygen supply).

The effective ventilation with supplementary oxygen during the early moment of resuscitation is essential during CPR. Also, it is recommended to monitor the efficacy of ventilation via capnometry which measures end-tidal CO2 . CPR is indicated to monitor the effectiveness of manoeuvres by obtaining a value between 10 and 20 mmHg. An abrupt increase of end-tidal CO2 values indicates return of spontaneous circulation (ROSC). If after oro-tracheal intubation, there is no waveform during CPR, but a flat line, this should alert for misplacement of endotracheal tube [1, 4, 6].

**Electrolyte abnormalities** can cause cardiac arrhythmias or cardiac arrest. Life-threatening arrhythmias are most commonly associated with potassium disorders. The main causes of hyperkalaemia are renal failure, drugs (e.g. angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, potassium-sparing diuretics), rhabdomyolysis, metabolic acidosis, Addison's disease, diet. The treatment strategies for hyperkalaemia are cardiac protection, shifting potassium into cells, removing potassium from the body, monitoring serum potassium and blood glucose [1, 4, 6].

The 2015 Guidelines for resuscitation published by European Resuscitation Council divide the resuscitation in special circumstances into three parts: special causes, special environ-

The first part covers treatment of potentially reversible causes of cardiac arrest, for which specific treatment exists and which are divided into two groups of four, called 'the 4Hs and 4Ts': hypoxia; hypo-/hyperkalaemia and other electrolyte disorders; hypo-/hyperthermia; hypovolaemia; tension pneumothorax; tamponade (cardiac tamponade); thrombosis (coronary and

The second part covers cardiac arrest in special environments, where universal guidelines should be modified due to specific locations or location-specific causes of cardiac arrest [1, 5]. The third part contains the recommendation for the patients with specific conditions and those with certain long-term comorbidities, where a modified approach and different treat-

**Hypoxia** is usually a consequence of asphyxia, which is defined as pathological changes caused by lack of oxygen in respired air, resulting in a deficiency of oxygen in the blood (hypoxia) and an increase in carbon dioxide in the blood and tissues (hypercapnia). Symptoms usually include irregular and disturbed respirations, or a complete absence of breathing, and pallor or cyanosis. Asphyxia may occur whenever there is an interruption in the normal exchange of oxygen and carbon dioxide between the lungs and the outside air. Some common causes are drowning, electric shock, hanging, suffocation, lodging of a foreign body in the air passages, inhalation of smoke and poisonous gases, and trauma to or disease of the lungs or air passages. Hypoxia requires ventilation with airway adjuncts that need to be verified to be placed correctly. There is necessary to check breath sounds at regular time intervals to ensure that the endotracheal tube has not slipped out of the trachea or to identify the presence of pneumothorax. Also is necessary to verify the source of oxygen (an oxygen cylinder or the

The effective ventilation with supplementary oxygen during the early moment of resuscitation is essential during CPR. Also, it is recommended to monitor the efficacy of ventilation via

manoeuvres by obtaining a value between 10 and 20 mmHg. An abrupt increase of end-tidal

**Electrolyte abnormalities** can cause cardiac arrhythmias or cardiac arrest. Life-threatening arrhythmias are most commonly associated with potassium disorders. The main causes of hyperkalaemia are renal failure, drugs (e.g. angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, potassium-sparing diuretics), rhabdomyolysis, metabolic

 values indicates return of spontaneous circulation (ROSC). If after oro-tracheal intubation, there is no waveform during CPR, but a flat line, this should alert for misplacement of

. CPR is indicated to monitor the effectiveness of

ments and special patients [4].

14 Resuscitation Aspects

pulmonary) and toxins (poisoning) [1, 4].

ment decisions may be necessary [4].

**2. Special causes**

piped oxygen supply).

endotracheal tube [1, 4, 6].

CO2

capnometry which measures end-tidal CO2

**Hypothermia**: accidental hypothermia is defined as an involuntary decrease of body core temperature <35°C. It is divided in five stages according to central core temperature: 1. mild hypothermia (conscious, shivering, core temperature 35–32°C); 2. moderate hypothermia (impaired consciousness without shivering, core temperature 32–28°C); 3. severe hypothermia (unconscious, vital signs present, core temperature 28–24°C); 4. cardiac arrest or low flow state (no or minimal vital signs, core temperature <24°C) and 5. death due to irreversible hypothermia (core temperature <13.7°C) [4].

Hypothermia decreases oxygen consumption at cellular level, so the heart and the brain can tolerate for a longer period of time cardiac arrest. This is the basic concept of the protective effect of hypothermia in cardiac arrest. Sometimes complete neurological recovery can be found even after prolonged cardiac arrest, but only if hypothermia was installed before respiratory arrest [1, 4, 6–9].

The first measure is to remove the patient from cold environment, remove clothes which are usually wet or cold and try to prevent any other heat loss. Quick mobilisation of patient with hypothermia can induce arrhythmias [1, 4, 6].

Hypothermia need to be treated with gradual rewarming using normal or electric blankets and warm IV fluids. The goal is to achieve an increase of temperature with a rate of 1–1.5°C per hour. It should be used IV fluid (normal saline, for example) heated at approx. 40°C and also gastric lavage, peritoneal lavage, bladder lavage, using fluids heated at approx. 40°C.

Monitor electrolytes disorder hourly, especially hyperkalaemia, which can appear during heating manoeuvres. Oxygen should be delivered also heated and humidified at 40°C, using a mechanical ventilator, after oro-tracheal intubation [1, 4–6].

Regarding CPR manoeuvres, in case of hypothermia-associated thoracic stiffness is present. Thus, chest compressions are harder to perform, and ventilation will require higher pressures than in normal situation [1, 4, 5, 7–9].

In case of ROSC, pulse in patients with hypothermia is very weak due to peripheral vasoconstriction, so is needed to consider Doppler examination to assess correctly the presence or absence of circulation.

Hypothermic patients without signs of cardiac instability (systolic blood pressure ≥90 mmHg, absence of ventricular arrhythmias or core temperature ≥28°C) can be rewarmed externally using minimally invasive techniques (warm air and warm intravenous fluid). Patients with signs of cardiac instability should be resuscitated in the field and transferred directly to a centre capable of extracorporeal life support (ECLS) [1, 4–9].

**Hypovolaemia** is a potentially treatable cause of cardiac arrest that usually results from a haemorrhage, but relative hypovolaemia may also occur in patients with severe vasodilation (e.g. anaphylaxis, sepsis). In case of anaphylaxis with relative hypovolaemia, the immediate treatment with intramuscular adrenaline is the treatment of choice, followed by IV fluids and corticoids prolonged CPR may be necessary [1, 4, 6, 10].

History of fluid or blood loss may be available. Rectal examination can identify massive lower GI bleeding; nasogastric intubation can identify massive upper GI bleeding, and bedside FAST can diagnose massive intraperitoneal bleeding. Treatment is with fluids (crystalloids, colloids), administered rapidly IV and blood products. If colloids are administered, blood samples are necessary before of this, to work compatibility cross-match blood test, because colloids can interfere with the results [1, 4, 6].

**Tension pneumothorax**: the mortality from traumatic cardiac arrest (TCA) is very high. The most common cause of death is haemorrhage, but the patients with trauma could have other reversible causes: hypoxia, tension pneumothorax, cardiac tamponade, and all of them must be immediately treated [1, 4, 5, 11–14].

The new treatment algorithm for traumatic cardiac arrest was developed to prioritise the sequence of life-saving measures. Chest compressions should not delay the treatment of reversible causes.

Suspect of tension pneumothorax during cardiac resuscitation if breath sounds are unequal on chest auscultation after verifying correct endotracheal tube placement. Other useful clinical sign for diagnosis are one immobile, distended hemi thorax; hyper resonance with percussion over the chest wall; trachea deviation to opposite side of tension pneumothorax and jugular veins distention. Treatment is immediate needle decompression or other technique to decompress the chest in TCA—to perform unilateral or bilateral thoracotomies in the 4th intercostal space. In the presence of positive pressure ventilation, thoracotomies are likely to be more effective than needle thoracentesis and quicker than inserting a chest tube [1, 5, 11–14].

**Cardiac tamponade** is the underlying cause of approximately 10% of cardiac arrest in trauma. Whereas there are TCA and penetrating trauma to the chest or epigastrium, immediate resuscitative thoracotomy (RT) can be lifesaving. If thoracotomy is not possible, consider ultrasound guided pericardiocentesis to treat cardiac arrest with cardiac tamponade. Cardiac tamponade is best identified during resuscitation by bedside transthoracic ultrasound. This requires brief interruption of chest compressions up to 10 s. Another useful ECG sign in cardiac tamponade is represented by microvoltage, in traumatic event context. Treatment of tamponade causing cardiac arrest is bedside pericardiocentesis [1, 4, 5, 12–14].

**Thrombosis** for the patients with out-of-hospital cardiac arrest (OHCA) of suspected cardiac origin, the transfer to the hospital with continuing CPR could be a solution in case of acute coronary syndrome–coronary thrombosis. Ground transport may be beneficial in selected patients where there is immediate hospital access to the catheterisation laboratory and an infrastructure providing prehospital and in-hospital teams experienced in mechanical or haemodynamic support and percutaneous coronary intervention (PCI) with ongoing CPR [1, 4, 15–19].

Acute coronary thrombosis or acute myocardial infarction is one of the most common causes of cardiac arrest. Risk factors are a history of coronary artery disease and initial rhythm of VF/ VT. Cardiac catheterisation after resuscitation is an underused procedure. A 12-lead ECG in the immediate postcardiac arrest state can identify an ST-elevation acute myocardial infarction and allows for arrangements of immediate coronary angiography. Myocardial and neurologic function can improve after percutaneous coronary intervention following cardiac arrest. Therefore, after ROSC, especially in the face of post-ROSC, ECG evidence of acute myocardial infarction, cardiac catheterisation and percutaneous coronary revascularisation is recommended, if available and appropriate [1, 4, 5].

treatment with intramuscular adrenaline is the treatment of choice, followed by IV fluids and

History of fluid or blood loss may be available. Rectal examination can identify massive lower GI bleeding; nasogastric intubation can identify massive upper GI bleeding, and bedside FAST can diagnose massive intraperitoneal bleeding. Treatment is with fluids (crystalloids, colloids), administered rapidly IV and blood products. If colloids are administered, blood samples are necessary before of this, to work compatibility cross-match blood test, because

**Tension pneumothorax**: the mortality from traumatic cardiac arrest (TCA) is very high. The most common cause of death is haemorrhage, but the patients with trauma could have other reversible causes: hypoxia, tension pneumothorax, cardiac tamponade, and all of them must

The new treatment algorithm for traumatic cardiac arrest was developed to prioritise the sequence of life-saving measures. Chest compressions should not delay the treatment of reversible

Suspect of tension pneumothorax during cardiac resuscitation if breath sounds are unequal on chest auscultation after verifying correct endotracheal tube placement. Other useful clinical sign for diagnosis are one immobile, distended hemi thorax; hyper resonance with percussion over the chest wall; trachea deviation to opposite side of tension pneumothorax and jugular veins distention. Treatment is immediate needle decompression or other technique to decompress the chest in TCA—to perform unilateral or bilateral thoracotomies in the 4th intercostal space. In the presence of positive pressure ventilation, thoracotomies are likely to be more effective than needle thoracentesis and quicker than inserting a chest tube [1, 5, 11–14].

**Cardiac tamponade** is the underlying cause of approximately 10% of cardiac arrest in trauma. Whereas there are TCA and penetrating trauma to the chest or epigastrium, immediate resuscitative thoracotomy (RT) can be lifesaving. If thoracotomy is not possible, consider ultrasound guided pericardiocentesis to treat cardiac arrest with cardiac tamponade. Cardiac tamponade is best identified during resuscitation by bedside transthoracic ultrasound. This requires brief interruption of chest compressions up to 10 s. Another useful ECG sign in cardiac tamponade is represented by microvoltage, in traumatic event context. Treatment of tamponade causing

**Thrombosis** for the patients with out-of-hospital cardiac arrest (OHCA) of suspected cardiac origin, the transfer to the hospital with continuing CPR could be a solution in case of acute coronary syndrome–coronary thrombosis. Ground transport may be beneficial in selected patients where there is immediate hospital access to the catheterisation laboratory and an infrastructure providing prehospital and in-hospital teams experienced in mechanical or haemodynamic

Acute coronary thrombosis or acute myocardial infarction is one of the most common causes of cardiac arrest. Risk factors are a history of coronary artery disease and initial rhythm of VF/ VT. Cardiac catheterisation after resuscitation is an underused procedure. A 12-lead ECG in

support and percutaneous coronary intervention (PCI) with ongoing CPR [1, 4, 15–19].

corticoids prolonged CPR may be necessary [1, 4, 6, 10].

cardiac arrest is bedside pericardiocentesis [1, 4, 5, 12–14].

colloids can interfere with the results [1, 4, 6].

be immediately treated [1, 4, 5, 11–14].

causes.

16 Resuscitation Aspects

Acute pulmonary embolism will be suspected by clinical symptoms such as dyspnoea, chest pain and syncope, either only one of this or in combination. Most frequent patient-related predisposing factors for developing pulmonary embolism include age, history of previous deep vein thrombosis, active cancer, neurological disease with extremity paresis, medical condition causing prolonged bed rest, such as heart or acute respiratory failure or post-surgery, congenital or acquired thrombophilia, hormone replacement therapy and oral contraceptive therapy [1, 4, 5, 15–17].

Electrocardiographic signs of RV strain, such as inversion of T waves in leads V1–V4, a QR pattern in lead V1, the classic pattern of S1Q3T3 ECG type and incomplete or complete right bundle-branch block, may be helpful also to raise the suspicion for pulmonary embolism.

The administration of fibrinolytic when pulmonary embolism is the suspected cause of cardiac arrest remains the actual recommendation. Pulmonary embolism causing cardiac arrest requires fibrinolysis or embolectomy. However, the diagnosis is rarely made at time of collapse, and even then, most systems are not geared to make such prompt diagnosis and initiate the necessary procedures for embolectomy [1, 4, 5, 15, 16, 19].

Fibrinolytic agents could be considered during cardiac arrest from suspected pulmonary embolism on a case-by-case basis. Factors suggestive of pulmonary embolism causing cardiac arrest include two of three signs/symptoms (prearrest respiratory distress, altered mental status or shock); arrest witnessed by a physician or emergency medical technician and PEA as the first or primary arrest rhythm. Ongoing CPR is not a contraindication to fibrinolysis, and after fibrinolytic drug is administered, CPR should be continued for at least 60–90 min before terminating resuscitation attempts [1, 4, 15–18, 20].

**Toxics**: airway obstruction and respiratory arrest secondary to a decreased conscious level is a common cause of cardiac arrest after accidental or self-poisoning. There are few specific therapeutic measures for poisoning that are useful immediately and during cardiopulmonary resuscitation and improve outcomes: decontamination, enhancing elimination and the use of specific antidotes.

The preferred method of gastrointestinal decontamination in patients with protected airways is activated charcoal but is most effective only if given within first hour from ingestion. Drug overdose is rarely identified as a cause of cardiac arrest during the resuscitation process. In the event of antidepressant overdose, administer IV sodium bicarbonate. Lipid emulsion infusion may be useful in cardiac arrest associated with cyclic antidepressants or local anaesthetics.

Opioid poisoning causes respiratory depression followed by respiratory insufficiency or respiratory arrest. The use of naloxone can prevent the need for intubation. The initial doses of naloxone are 0.4–2 mg IV, IO, IM or SC and may be repeated every 2–3 min. Additional doses may be needed every 20–60 min. Titrate the dose until the victim is breathing adequately and has protective airway reflexes [4, 5, 21].

### **3. Special environment**

The special environments include cardiac arrest in specific locations: operating theatre, cardiac surgery, catheterisation laboratory, dialysis unit, dental surgery, commercial airplanes or medical helicopters, field of play, outside environment (e.g. drowning, remote area, high altitude, avalanche, lightning strike and electrical injuries) or the scene of a mass casualty incident.

Cardiac arrest following major **cardiac surgery** is relatively common in the immediate postoperative phase. Perioperative cardiac arrest may be caused by the physiological effects of the surgery, bleeding, general anaesthesia (failure of ventilation, medication-related events, complications associated with central venous access, drugs or blood administration, perioperative myocardial infarction) [22–24] or complications relating to pre-existing comorbidities.

The management of perioperative cardiac arrest starts with advanced life support (ALS) algorithm, but with appropriate modifications depending on the cause identified. Key to successful resuscitation is recognition of the need to perform emergency re-sternotomy, especially in the context of tamponade or haemorrhage, where external chest compressions may be ineffective. Re-sternotomy should be performed within 5 min if other interventions have failed.

Cardiac arrest may occur during percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) or non-STEMI, or it may be a complication during angiography as air or thrombus embolism in the coronary artery, artery intima dissection or pericardial tamponade. A defibrillator must be available in the angiography room, and self-adhesive defibrillation pads may already be placed at the beginning of the procedure in high-risk patients.

Cardiac arrest from shockable rhythms (ventricular fibrillation or pulseless ventricular tachycardia) during **cardiac catheterisation** should immediately be treated with up to three stacked shocks before starting chest compressions. Use of mechanical chest compression devices during angiography is recommended to ensure high-quality chest compressions and reduce the radiation of the personnel during angiography with ongoing CPR.

Most of the standard reversible causes (4Hs and 4Ts) apply to **dialysis patients**. Electrolyte disorders, particularly hyperkalaemia and hypoxia, due to fluid overload with pulmonary edema are most common causes of cardiac arrest in dialysis unit.

During cardiopulmonary resuscitation, it follows the universal ALS algorithm, and the dialysis access open for drug administration A shockable rhythm (VF/pulseless VT) is more common in patients undergoing haemodialysis than in the general population [25–29]. So the delay in delivering defibrillation must be minimised.

In **dental surgery**, causes of cardiac arrest are related to pre-existing comorbidities (acute myocardial infarction, grand mal seizures or exacerbation of asthma), loss of airway patency related to the primary pathology or complications of the procedure (e.g. bleeding, secretions, tissue swelling) or anaphylaxis to local anaesthetics.

naloxone are 0.4–2 mg IV, IO, IM or SC and may be repeated every 2–3 min. Additional doses may be needed every 20–60 min. Titrate the dose until the victim is breathing adequately and

The special environments include cardiac arrest in specific locations: operating theatre, cardiac surgery, catheterisation laboratory, dialysis unit, dental surgery, commercial airplanes or medical helicopters, field of play, outside environment (e.g. drowning, remote area, high altitude, avalanche, lightning strike and electrical injuries) or the scene of a mass casualty incident. Cardiac arrest following major **cardiac surgery** is relatively common in the immediate postoperative phase. Perioperative cardiac arrest may be caused by the physiological effects of the surgery, bleeding, general anaesthesia (failure of ventilation, medication-related events, complications associated with central venous access, drugs or blood administration, perioperative myocardial infarction) [22–24] or complications relating to pre-existing comorbidities. The management of perioperative cardiac arrest starts with advanced life support (ALS) algorithm, but with appropriate modifications depending on the cause identified. Key to successful resuscitation is recognition of the need to perform emergency re-sternotomy, especially in the context of tamponade or haemorrhage, where external chest compressions may be ineffective. Re-sternotomy should be performed within 5 min if other interventions have failed. Cardiac arrest may occur during percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) or non-STEMI, or it may be a complication during angiography as air or thrombus embolism in the coronary artery, artery intima dissection or pericardial tamponade. A defibrillator must be available in the angiography room, and self-adhesive defibrillation pads may already be placed at the beginning of the procedure in high-risk patients. Cardiac arrest from shockable rhythms (ventricular fibrillation or pulseless ventricular tachycardia) during **cardiac catheterisation** should immediately be treated with up to three stacked shocks before starting chest compressions. Use of mechanical chest compression devices during angiography is recommended to ensure high-quality chest compressions and reduce the

radiation of the personnel during angiography with ongoing CPR.

edema are most common causes of cardiac arrest in dialysis unit.

delay in delivering defibrillation must be minimised.

Most of the standard reversible causes (4Hs and 4Ts) apply to **dialysis patients**. Electrolyte disorders, particularly hyperkalaemia and hypoxia, due to fluid overload with pulmonary

During cardiopulmonary resuscitation, it follows the universal ALS algorithm, and the dialysis access open for drug administration A shockable rhythm (VF/pulseless VT) is more common in patients undergoing haemodialysis than in the general population [25–29]. So the

In **dental surgery**, causes of cardiac arrest are related to pre-existing comorbidities (acute myocardial infarction, grand mal seizures or exacerbation of asthma), loss of airway patency

has protective airway reflexes [4, 5, 21].

**3. Special environment**

18 Resuscitation Aspects

The patient will not be moved from the dental chair to start CPR, the dental chair will be reclined into a horizontal position or a stool will be placed under the head to increase its stability during CPR. Consider the over-the-head technique of CPR, if access of the chest is limited [30–32].

**Cardiopulmonary resuscitation on the airplane**: in case of cardiac arrest, universal algorithm for adult basic life support and automated external defibrillation (AED) will be followed, but performance of CPR is limited in an aircraft due to space restriction, so consider the transfer of the patient to a larger space. Consider an over-the-head technique of CPR if access precludes conventional PR [30–32].

If the CPR equipment is available, attach oxygen to the facemask or self-inflating bag. Request immediate flight diversion to the nearest appropriate airport. The in-flight use of AEDs aboard commercial airplanes can result in up to 50% survival to hospital discharge [4]. AEDs and appropriate CPR equipment should be mandatory on board of all commercial aircraft in Europe, including regional and low-cost carriers [33].

The incidence of cardiac arrest on board of **helicopter emergency medical services** (HEMS) and air ambulances is low. Cardiac arrest may occur in-flight, both in patients being transported from a primary intervention site and also critical patients transferred between hospital [34]. The pre-flight preparation is important for the patients with high risk of cardiac arrest and use of mechanical chest compression devices are emphasised [4, 5].

Sudden and unexpected collapse of a sportsman **during exercises or on the field of play** is likely to be cardiac in origin and requires rapid recognition, initiating basic life support (BLS) and early defibrillation. If the athlete responds to resuscitation, then he/she must be transported immediately to the nearest cardiac centre for further evaluation and treatment [4, 5].

For **drowning patients**, bystanders play an essential role in early rescue and high-quality resuscitation. The victim needs to be removed from the water promptly. Resuscitation strategies for those in respiratory or cardiac arrest continue to prioritise oxygenation and ventilation. Inflation should take about 1 s and be sufficient to see the chest rise [4, 5].

Rescue breaths/ventilation will continue until an ALS team arrives and is ready to intubate the victim. Palpation of the pulse is not always reliable. As soon as possible, use information from monitoring modalities such as the ECG, end-tidal CO2 , and echocardiography to confirm the diagnosis of cardiac arrest. If the drowning victim is hypothermic or hypovolaemic, modify the ALS approach in accordance with the treatment of hypothermia and give IV warm fluid.

The chances of good outcome from cardiac arrest in **difficult terrain or mountains** may be reduced because of delayed access and prolonged transport. There is a recognised role of air rescue and availability of AEDs in remote but often-visited locations [4, 35]. Resuscitation at high altitude does not differ from standard CPR. CPR is more exhausting for a single rescuer than at sea level, due to lower pO2 , and the average number of effective chest compressions may decrease within the first minute [36].

For **avalanche victims** in cardiac arrest, prolonged CPR and extracorporeal rewarming are indicated. Cardiac arrest secondary to avalanche is mainly due to asphyxia associated with trauma and hypothermia. In all cases, extricate the body gently and use spinal precautions. Extracorporeal life support (ECLS) is indicated if the duration of burial is >60 min, core temperature at extrication is <30°C and serum potassium at hospital admission is ≤8 mmol L−1 [4, 35, 37].

Safety measures are essential for providing CPR to the victim of an **electrical injury** [4]. Factors influencing the severity of electrical injury include the current type alternating (AC) or direct (DC), voltage, magnitude of energy delivered, resistance to current flow, the area and duration of contact. As with industrial and domestic electric shock, after lightning strikes death is caused by cardiac or respiratory arrest [38–41].

Ensure that any power source is switched off and approach the casualty only if it is safe and start standard BLS and ALS without delay. Airway management may be difficult, and early tracheal intubation is needed if there are electrical burns around the face and neck. Head and spine trauma can occur after electrocution, and the spine immobilisation must be performed.

VF is the commonest initial arrhythmia after high-voltage AC shock, and prompt defibrillation is essential. Asystole is more common after DC shock with standard ALS protocols.

Unlike normal circumstances, CPR is not usually initiated in **mass casualty incidents** (MCI), in order to avoid delaying potentially effective treatment for the critically ill but salvageable victims. This critical decision depends on available medical and paramedical resources in relation to the number of casualties.

A triage system should be used to prioritise treatment and, if the number of casualties overwhelms the prehospital medical resources, withhold CPR for the patients without signs of life [1, 5]. For triage, the START triage is used. The first step is that everyone able to walk is directed to clear the scene, and respiratory status of nonwalking patients is assessed. If the casualty does not breathe, open the airway using head tilt and chin lift or jaw thrust. Assess breathing for no more than 10 s and if a patient does not begin breathing is declared dead. If an unresponsive victim is breathing normally, turn them into the recovery position and label as red-highest priority for treatment. The same goes for the patient with sign of hemodynamic instability.

Perform life-saving interventions in patients triaged as red (highest priority) to prevent cardiac arrest: control major haemorrhage, open airway using basic techniques, perform chest decompression for tension pneumothorax, use antidotes and consider initial rescue breaths in a nonbreathing child [42].

### **4. Special patients**

Special patients with special guidance for CPR are considered to be the patients with severe comorbidities: asthma, heart failure with ventricular assist devices, neurological disease, obesity and those with specific physiological conditions (pregnancy, elderly people).

Cardiac arrest in a patient with **asthma** is often a terminal event after a hypoxemic period or it may be sudden. CA is linked to:


For **avalanche victims** in cardiac arrest, prolonged CPR and extracorporeal rewarming are indicated. Cardiac arrest secondary to avalanche is mainly due to asphyxia associated with trauma and hypothermia. In all cases, extricate the body gently and use spinal precautions. Extracorporeal life support (ECLS) is indicated if the duration of burial is >60 min, core temperature at extrication is <30°C and serum potassium at hospital admission is ≤8 mmol L−1 [4,

Safety measures are essential for providing CPR to the victim of an **electrical injury** [4]. Factors influencing the severity of electrical injury include the current type alternating (AC) or direct (DC), voltage, magnitude of energy delivered, resistance to current flow, the area and duration of contact. As with industrial and domestic electric shock, after lightning strikes

Ensure that any power source is switched off and approach the casualty only if it is safe and start standard BLS and ALS without delay. Airway management may be difficult, and early tracheal intubation is needed if there are electrical burns around the face and neck. Head and spine trauma can occur after electrocution, and the spine immobilisation must be performed. VF is the commonest initial arrhythmia after high-voltage AC shock, and prompt defibrillation is essential. Asystole is more common after DC shock with standard ALS protocols.

Unlike normal circumstances, CPR is not usually initiated in **mass casualty incidents** (MCI), in order to avoid delaying potentially effective treatment for the critically ill but salvageable victims. This critical decision depends on available medical and paramedical resources in

A triage system should be used to prioritise treatment and, if the number of casualties overwhelms the prehospital medical resources, withhold CPR for the patients without signs of life [1, 5]. For triage, the START triage is used. The first step is that everyone able to walk is directed to clear the scene, and respiratory status of nonwalking patients is assessed. If the casualty does not breathe, open the airway using head tilt and chin lift or jaw thrust. Assess breathing for no more than 10 s and if a patient does not begin breathing is declared dead. If an unresponsive victim is breathing normally, turn them into the recovery position and label as red-highest priority for treatment. The same goes for the patient with sign of hemodynamic

Perform life-saving interventions in patients triaged as red (highest priority) to prevent cardiac arrest: control major haemorrhage, open airway using basic techniques, perform chest decompression for tension pneumothorax, use antidotes and consider initial rescue breaths

Special patients with special guidance for CPR are considered to be the patients with severe comorbidities: asthma, heart failure with ventricular assist devices, neurological disease, obe-

sity and those with specific physiological conditions (pregnancy, elderly people).

death is caused by cardiac or respiratory arrest [38–41].

relation to the number of casualties.

in a nonbreathing child [42].

**4. Special patients**

35, 37].

20 Resuscitation Aspects

instability.

These high-risk patients should be treated to prevent deterioration with oxygen to achieve an SpO2 94–98%, inhaled beta-2 agonists (salbutamol 5 mg) or intravenous beta-2 agonists for those patients in whom inhaled therapy cannot be used reliably, nebulised anticholinergics (ipratropium, 0.5 mg 4–6 hourly), nebulised magnesium sulphate, intravenous corticosteroids, intravenous bronchodilators and aminophylline, a dose of 5 mg kg−1 over 20–30 min. In cases of severe asthma associated with dehydration and hypovolemia IV fluids are necessary.

In case of cardiac arrest BLS is performed according to standard guidelines. Ventilation could be difficult because of increased airway resistance.

Modifications to standard ALS guidelines include the need for early tracheal intubation. The peak airway pressures recorded during ventilation of patients with severe asthma are significantly higher than the normal lower oesophageal sphincter pressure (approximately 20 cm H2 O) [43, 44].

Respiratory rates of 8–10 breaths/min and a tidal volume required for a normal chest rise during CPR should minimise dynamic hyperinflation of the lungs [air trapping].

Tidal volume depends on inspiratory time and inspiratory flow. Lung emptying depends on expiratory time and expiratory flow. In mechanically ventilated severe asthmatics, increasing the expiratory time (achieved by reducing the respiratory rate) provides only moderate gains in terms of reduced gas trapping when a minute volume of less than 10 L min−1 is used [44].

Dynamic hyperinflation increases transthoracic impedance [45] but modern impedancecompensated biphasic defibrillation waveforms are no less effective in patients with higher impedance. Consider increasing defibrillation energy if the first shock is unsuccessful, and a manual defibrillator is available [4].

There is no good evidence for the use of open-chest cardiac compressions in patients with asthma-associated cardiac arrest. Looking through the four H's and four T's will identify potentially reversible causes of asthma-related cardiac arrest, often tension pneumothorax. This pathologic situation may be indicated by unilateral expansion of the chest wall, shifting of the trachea and subcutaneous emphysema. If a pneumothorax is suspected, perform needle decompression using a large-gauge cannula, followed by insertion of a chest tube.

In patients with **ventricular assist devices** (VADs), confirmation of cardiac arrest may be difficult. The management of patients with VADs is more complex, in that a cardiac arrest may be due to mechanical failure and may be actions specific to the device that are required. In any cases, external chest compression in patients with ventricular assist devices is not successful without damage to the VAD.

Transthoracic/transesophageal echocardiography, capnography or Doppler flow in a major artery may assist in the cardiac arrest diagnosis. If cardiac arrest is confirmed, start CPR, check the rhythm and perform defibrillation for shockable rhythms (VF/VT), start pacing for asystole. If during the first 10 days of surgery, cardiac arrest does not respond to defibrillation, perform re-sternotomy immediately.

Cardiac arrest associated with **acute neurological disease** is relatively uncommon and can appear in subarachnoid haemorrhage, intracerebral haemorrhage, epileptic seizures and ischemic stroke and in brain injury associated with trauma [46].

The mechanism of cardiac arrest in neurological disease is related to:


Patients with subarachnoid haemorrhage may have ECG changes that suggest an acute coronary syndrome. Whether a computed tomography brain scan is done before or after coronary angiography will depend on clinical judgement regarding the likelihood of a subarachnoid haemorrhage versus acute coronary syndrome.

For resuscitation of **obese patients**, in order to maintain sufficient depth of chest compressions (approximately 5 cm but no more than 6 cm), consider changing rescuers more frequently than the standard 2-min interval. Early tracheal intubation by an experienced physician is recommended. Use of mechanical resuscitation devices is limited by the slope of the anterior chest wall and thoracic dimensions.

Optimal defibrillation energy levels in obese patients are unknown [4]. So the recommended energy remains the same (150–360 J). Unlike monophasic defibrillators, modern biphasic defibrillators are impedance compensated and adjust their output according to the patient's impedance. Defibrillation protocols for obese patients should therefore follow those recommended for patients with a normal BMI and consider higher shock energies for defibrillation if initial defibrillation attempts fail.

For the **pregnant woman** in cardiac arrest, high-quality CPR with manual uterine displacement, early ALS and emergent delivery of the foetus if early return of spontaneous circulation (ROSC) is not achieved remain key interventions.

Foetal survival usually depends on maternal survival and initial resuscitation efforts should focus on the pregnant mother.

In patients with **ventricular assist devices** (VADs), confirmation of cardiac arrest may be difficult. The management of patients with VADs is more complex, in that a cardiac arrest may be due to mechanical failure and may be actions specific to the device that are required. In any cases, external chest compression in patients with ventricular assist devices is not successful

Transthoracic/transesophageal echocardiography, capnography or Doppler flow in a major artery may assist in the cardiac arrest diagnosis. If cardiac arrest is confirmed, start CPR, check the rhythm and perform defibrillation for shockable rhythms (VF/VT), start pacing for asystole. If during the first 10 days of surgery, cardiac arrest does not respond to defibrilla-

Cardiac arrest associated with **acute neurological disease** is relatively uncommon and can appear in subarachnoid haemorrhage, intracerebral haemorrhage, epileptic seizures and isch-

(a) loss of consciousness, causing airway obstruction, hypoxemia and respiratory arrest followed by cardiac arrest, or an increased risk of aspiration of gastric contents into the lungs

(c) arrhythmias and myocardial dysfunction associated with acute neurological injury (e.g.

Patients with subarachnoid haemorrhage may have ECG changes that suggest an acute coronary syndrome. Whether a computed tomography brain scan is done before or after coronary angiography will depend on clinical judgement regarding the likelihood of a subarachnoid

For resuscitation of **obese patients**, in order to maintain sufficient depth of chest compressions (approximately 5 cm but no more than 6 cm), consider changing rescuers more frequently than the standard 2-min interval. Early tracheal intubation by an experienced physician is recommended. Use of mechanical resuscitation devices is limited by the slope of the anterior

Optimal defibrillation energy levels in obese patients are unknown [4]. So the recommended energy remains the same (150–360 J). Unlike monophasic defibrillators, modern biphasic defibrillators are impedance compensated and adjust their output according to the patient's impedance. Defibrillation protocols for obese patients should therefore follow those recommended for patients with a normal BMI and consider higher shock energies for defibrillation

For the **pregnant woman** in cardiac arrest, high-quality CPR with manual uterine displacement, early ALS and emergent delivery of the foetus if early return of spontaneous circulation

(b) respiratory and cardiac depression caused by compression of the brain stem

without damage to the VAD.

22 Resuscitation Aspects

tion, perform re-sternotomy immediately.

sub-arachnoid haemorrhage)

chest wall and thoracic dimensions.

if initial defibrillation attempts fail.

(ROSC) is not achieved remain key interventions.

(d) Sudden unexpected death in epilepsy [4].

haemorrhage versus acute coronary syndrome.

emic stroke and in brain injury associated with trauma [46].

The mechanism of cardiac arrest in neurological disease is related to:

From 20 weeks' gestation, the uterus can compress the inferior vena cava (IVC) and aorta, impeding venous return and cardiac output and therefore can cause pre-arrest hypotension or shock and, in the critically ill patient, may precipitate cardiac arrest [47, [49]]. During cardiac arrest, the compromise in venous return and cardiac output by the gravid uterus limits the effectiveness of chest compressions. Manually displace the uterus to the left is recommended to reduce IVC compression.

During CPR, the hand position for chest compressions may need to be slightly higher on the sternum for patients with advanced pregnancy—third trimester [48].

During BLS and ALS, pregnant patients are at risk of aspiration and oxygenation and ventilation are the priority over aspiration prevention. Early tracheal intubation (using a tracheal tube 0.5–1 mm internal diameter smaller than that used for a non-pregnant woman) with mechanical ventilation will however make ventilation of the lungs easier in the presence of increased intra-abdominal pressure.

The 4Hs and 4Ts approach helps identify all the common causes of cardiac arrest in pregnancy. The most important causes are


Consider the need for an emergency hysterectomy or Caesarean section as soon as a pregnant woman goes into cardiac arrest. Delivery will relieve IVC compression and may improve chances of maternal resuscitation. Seek for help and ask gynaecologist and neonatologist to start preparing for emergency caesarean section—the foetus will need to be delivered if initial resuscitation efforts fail. The caesarean delivery also enables access to the infant so that newborn resuscitation can begin [4].

**Elderly people** have an increased incidence of cardiac causes of arrest because the incidence of coronary heart disease and chronic heart failure increases with age. The incidence of PEA as the first recorded rhythm increases significantly with age with a decrease of the incidence of shockable rhythms (VF/pulseless VT) [4]. No modifications of standard resuscitation protocols are needed for aged patients in cardiac arrest. Rescuers should be aware that the risk of both sternal and rib fractures is higher in elderly and the incidence of CPR-related injuries increases with duration of CPR [51]. When deciding to resuscitate elderly patients, age alone should not be the element to consider and other more established criteria (witnessed arrest, resuscitation times, first recorded rhythm, the degree of autonomy, quality of life, mental status and presence of major comorbidities) are important factors. Whenever possible, a decision to resuscitate or not should be discussed in advance with the patient and his family.

Special circumstances in cardiac arrest need special interventions with an appropriate approach of guidelines for cardiopulmonary resuscitation.

### **Author details**

Diana Carmen Cimpoesu1,2\* and Tudor Ovidiu Popa1,2

\*Address all correspondence to: dcimpoiesu@yahoo.com

1 University of Medicine and Pharmacy Gr.T.Popa, Iasi, Romania

2 Emergency Department, Emergency County Hospital Sf.Spiridon, Iasi, Romania

### **References**


[7] Lexow K. Severe accidental hypothermia: survival after 6 hours 30 minutes of cardiopulmonary resuscitation. Arctic Med Res 1991;**50**:112-4.44.

increases with duration of CPR [51]. When deciding to resuscitate elderly patients, age alone should not be the element to consider and other more established criteria (witnessed arrest, resuscitation times, first recorded rhythm, the degree of autonomy, quality of life, mental status and presence of major comorbidities) are important factors. Whenever possible, a decision

Special circumstances in cardiac arrest need special interventions with an appropriate app-

to resuscitate or not should be discussed in advance with the patient and his family.

2 Emergency Department, Emergency County Hospital Sf.Spiridon, Iasi, Romania

emergency medicine. UMF "Gr. T. Popa" Publishing House, Iasi 2011.

[1] Cimpoesu D. [coordinator], Rotaru L, Petris A et al. Current protocols and guidelines in

[2] Nikolaos Nikolaou, Maaret Castrén, Koenraad G. Monsieurs, Diana Cimpoesu, Marios Georgiou, Violetta Raffay, Rudolph Koster, Silvija Hunyadi-Anticevi, Anatolij Truhlárˇ, Leo Bossaert, The EUROCALL investigators. Time delays to reach dispatch centres in different regions in Europe. Are we losing the window of opportunity? — The EUROCALL

[3] Jan-Thorsten Gräsner, Leo L.Bossaert, Diana Cimpoesu et al., EuReCa ONE – 27 Nations, ONE Europe, ONE Registry. A prospective one month analysis of out-of-hospital cardiac arrest outcomes in 27 countries in Europe, Resuscitation, Vol. 105:188-195, http://

[4] European R7esuscitation Council Guidelines for Resuscitation 2015, Truhlář A, Barelli,

[5] Soar J, Perkins GD, Abbas G, et al. European Resuscitation Council Guidelines for Resuscitation 2010 Section 8. Cardiac arrest in special circumstances: electrolyte abnormalities, poisoning, drowning, accidental hypothermia, hyperthermia, asthma, anaphylaxis, cardiac surgery, trauma, pregnancy, electrocution. Resuscitation 2010;**81**:1400-33.

[6] Judith E. Tintinalli, et. al.-Tintinalli's Emergency Medicine A Comprehensive Study Guide, 8th edition McGraw-Hill Publishing House, NewYork, 2016, ISBN: 007179476X

roach of guidelines for cardiopulmonary resuscitation.

Diana Carmen Cimpoesu1,2\* and Tudor Ovidiu Popa1,2

study. Resuscitation 111 [2017] 8-13

dx.doi.org/10.1016/j.resuscitation.2016.06.004

Al et al. Resuscitation, Volume 95, 148-201

\*Address all correspondence to: dcimpoiesu@yahoo.com

1 University of Medicine and Pharmacy Gr.T.Popa, Iasi, Romania

**Author details**

24 Resuscitation Aspects

**References**


[35] Brugger H, Paal P, Boyd J. Prehospital resuscitation of the buried avalanche victim. High Alt Med Biol 2011;**12**:199-205.

[20] Bottiger BW, Arntz HR, Chamberlain DA, et al. Thrombolysis during resuscitation for

[21] Mowry JB, Spyker DA, Cantilena Jr LR, McMillan N, Ford M. 2013 Annual Report of the American Association of Poison Control Centers' National Poison Data System [NPDS]:

[22] Nunnally ME, O'Connor MF, Kordylewski H, Westlake B, Dutton RP. The incidence and risk factors for perioperative cardiac arrest observed in the national anesthesia clinical

[23] Sprung J, Warner ME, Contreras MG, et al. Predictors of survival following cardiac arrest in patients undergoing noncardiac surgery: a study of 518,294 patients at a tertiary

[24] Newland MC, Ellis SJ, Lydiatt CA, et al. Anesthetic-related cardiac arrest and its mortality: a report covering 72,959 anesthetics over 10 years from a US teaching hospital.

[25] Davis TR, Young BA, Eisenberg MS, Rea TD, Copass MK, Cobb LA. Outcome of cardiac arrests attended by emergency medical services staff at community outpatient dialysis

[26] Lafrance JP, Nolin L, Senecal L, Leblanc M. Predictors and outcome of cardiopulmonary resuscitation [CPR] calls in a large haemodialysis unit over a seven-year period. Nephrol

[27] Meaney PA, Nadkarni VM, Kern KB, Indik JH, Halperin HR, Berg RA. Rhythms and outcomes of adult in-hospital cardiac arrest. Critical care medicine 2010;**38**:101-8. [28] Girotra S, Nallamothu BK, Spertus JA, et al. Trends in survival after in-hospital cardiac

[29] Bird S, Petley GW, Deakin CD, Clewlow F. Defibrillation during renal dialysis: a survey of UK practice and procedural recommendations. Resuscitation 2007;**73**:347-53.

[30] Perkins GD, Stephenson BT, Smith CM, Gao F. A comparison between over-the-head

[31] Handley AJ, Handley JA. Performing chest compressions in a confined space.

[32] Maisch S, Issleib M, Kuhls B, et al. A comparison between over-the-head and standard cardiopulmonary resuscitation performed by two rescuers: a simulation study. The

[33] Hung KK, Cocks RA, Poon WK, Chan EY, Rainer TH, Graham CA. Medical volunteers in commercial flight medical diversions. Aviat Space Environ Med. 2013;**84**:491-7. [34] Lyon RM, Nelson MJ. Helicopter emergency medical services [HEMS] response to outof-hospital cardiac arrest. Scandinavian journal of trauma, resuscitation and emergency

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26 Resuscitation Aspects

Dial Transplant 2006;**21**:1006-12.

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**Provisional chapter**

## **Resuscitation of Obstetric Patient**

**Resuscitation of Obstetric Patient**

Daniel Molano Franco and María Velez Maya Daniel Molano Franco and María Velez Maya Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.68420

### **Abstract**

[49] Nolan JP, Soar J, Wenzel V, Paal P. Cardiopulmonary resuscitation and management of

[50] Geoghegan J, Daniels JP, Moore PA, Thompson PJ, Khan KS, Gulmezoglu AM. Cell salvage at caesarean section: the need for an evidence-based approach. BJOG 2009;**116**:743-7.

[51] Kashiwagi Y, Sasakawa T, Tampo A, et al. Computed tomography findings of complications resulting from cardiopulmonary resuscitation. Resuscitation 2015;**88**:86-91.

cardiac arrest. Nat Rev Cardiol 2012;**9**:499-511.

28 Resuscitation Aspects

The number of cases of pregnant patients with cardiorespiratory arrest requiring resuscitation has increased worldwide, secondary to the main number of patients with high-risk pregnancies associated with chronic, especially cardiopulmonary, pathologies. The knowledge of the resuscitation algorithms by the health personnel responsible for the care of pregnant patients is mandatory, because due to different physiological and anatomical changes, there are particularities in the management and use of medications. In addition, a detailed description of the steps included in the resuscitation is necessary, where assessment of the airway, ventilation, circulation, and defibrillation determines a step in resuscitation. One of the determining and exclusive events in this type of patients is cesarea perimortem. That is why it includes a concrete description of the time and the indications for its realization. Finally, a list of medicines most used in resuscitation in pregnancy, with its dosage and safety range, is mentioned. The pregnant patient poses a challenge to resuscitation teams. This review refers to the recommendations for establishing "obstetric blue code" protocols at the institutional level.

DOI: 10.5772/intechopen.68420

**Keywords:** reanimation, maternal arrest, pregnancy, cardiopulmonary, perimortem caesarean

### **1. Introduction**

The approach to resuscitation in pregnancy determines several conditions that go from the physiological, anatomical, and emotional point of view, as we face a catastrophic event and the challenge of restoring the health condition of two living beings as a mother [1].Knowledge and training in resuscitation of the obstetric patient has had a great development in the last decade, with an increasing number of publications and special chapters in the international guides of resuscitation [2].

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Although maternal mortality worldwide has declined by 44%, there has been a worrying increase in extreme maternal morbidity and mortality in developed countries around the world due to increased pregnancy age and comorbidities that determine a greater number of situations of cardiac arrest[3].

In the USA, the prevalence of events requiring cardiac resuscitation in hospitalized obstetric patients was 8.5 × 100,000, with a survival rate of only 59% in the mother [4].

We believe that the scope of this chapter includes the knowledge of the various groups responsible for mother–child resuscitation, such as emergency physicians, obstetricians, anesthesiologists, critical care physicians, and neonatologists, as well as nurses and midwives.

### **2. Changes physiologic in the mother**

The physiological and anatomical changes of pregnancy require some modifications in the resuscitation protocols, these changes begin early in pregnancy, reach their peak during the second trimester, and then, remain relatively constant until delivery.

The major hemodynamic changes induced by pregnancy include an increase in cardiac output between 30 and 40% (as a result of increased stroke volume and to a lesser extent increased maternal heart rate 15–20 bpm) [5], plasma volume expansion is 10–15% at 6–12 weeks of gestation, and at the term, is 30–50% higher than non-pregnant women, increase in red cell volume [6] (a greater increase in intravascular volume than red cell mass, that results in the dilutional or physiologic anemia of pregnancy), reductions in systemic vascular resistance and systemic blood pressure [7].

Most of the increase in cardiac output is distributed in the placenta, kidneys, and skin so that the mechanical effects of the gravid uterus can decrease venous return from the inferior vena cava and obstruct blood flow through the abdominal aorta; all of above, contribute to unsuccessful cardiopulmonary resuscitation. Left lateral uterine displacement is necessary in the pregnant patient with fundal height at or above the umbilicus, to minimize aortocaval compression, to optimize venous return, and to generate adequate stroke volume during cardiopulmonary resuscitation [6].

During pregnancy, the anatomy of the upper respiratory airway undergoes numerous changes; upper airway, the pharynx and larynx edema occur as a result of hormonal effects and may reduce visualization during laryngoscopy and therefore, intubation in a pregnant woman can be difficult, and smaller endotracheal tubes may be needed[6, 8].. Therefore,progesterone relaxes gastroesophageal sphincters and prolongs transit times throughout the intestinal tract, predisposing the patient to aspiration of stomach contents [9].

Changes in the thorax and abdomen appear early in pregnancy; even before displacement from the enlarging uterus. In the first trimester, the subcostal angle changes from 68 to 103°, the diaphragm rises by up to 4 cm and the chest diameter increases by 2 cm or more, diaphragmatic excursion increases by up to 2 cm (the result is "barrel chested" appearance)[8].

Since the first trimester of pregnancy, a relative hyperventilation occurs, with minute ventilation rise by 50% at term, mediated by the elevated serum progesterone levels. This produces a mild respiratory alkalosis with compensatory renal excretion of bicarbonate [8].

The functional residual capacity decreases approximately 20% due to the upward shift in the diaphragm as the uterus enlarges, while oxygen consumption increases by 20% during pregnancy to meet the increased oxygen demands of the placenta, fetus and maternal organs. These two factors are responsible for hypoventilation in the pregnant woman [5, 9].

Forced expiratory volume (FEV1) does not change during pregnancy, but expiratory reserve volume and residual volume decrease, inspiratory capacity is mildly increased, resulting in a minimal drop in the total lung capacity from 4.2 to 4 l, In addition, there is a decrease in arterial carbon dioxide (PaCO<sup>2</sup> ) levels from 40 mmHg in non-pregnant to 27–32 mmHg during pregnancy, so that, the resultant arterial pH is normal to slightly alkalotic (between 7.40 and 7.45). The decrease in PaCO<sup>2</sup> helps the fetus to eliminate carbon dioxide across the placenta [9].

### **3. Etiology**

Although maternal mortality worldwide has declined by 44%, there has been a worrying increase in extreme maternal morbidity and mortality in developed countries around the world due to increased pregnancy age and comorbidities that determine a greater number of

In the USA, the prevalence of events requiring cardiac resuscitation in hospitalized obstetric

We believe that the scope of this chapter includes the knowledge of the various groups responsible for mother–child resuscitation, such as emergency physicians, obstetricians, anesthesiologists, critical care physicians, and neonatologists, as well as nurses and midwives.

The physiological and anatomical changes of pregnancy require some modifications in the resuscitation protocols, these changes begin early in pregnancy, reach their peak during the

The major hemodynamic changes induced by pregnancy include an increase in cardiac output between 30 and 40% (as a result of increased stroke volume and to a lesser extent increased maternal heart rate 15–20 bpm) [5], plasma volume expansion is 10–15% at 6–12 weeks of gestation, and at the term, is 30–50% higher than non-pregnant women, increase in red cell volume [6] (a greater increase in intravascular volume than red cell mass, that results in the dilutional or physiologic anemia of pregnancy), reductions in systemic vascular resistance

Most of the increase in cardiac output is distributed in the placenta, kidneys, and skin so that the mechanical effects of the gravid uterus can decrease venous return from the inferior vena cava and obstruct blood flow through the abdominal aorta; all of above, contribute to unsuccessful cardiopulmonary resuscitation. Left lateral uterine displacement is necessary in the pregnant patient with fundal height at or above the umbilicus, to minimize aortocaval compression, to optimize venous return, and to generate adequate stroke volume during car-

During pregnancy, the anatomy of the upper respiratory airway undergoes numerous changes; upper airway, the pharynx and larynx edema occur as a result of hormonal effects and may reduce visualization during laryngoscopy and therefore, intubation in a pregnant

gesterone relaxes gastroesophageal sphincters and prolongs transit times throughout the

Changes in the thorax and abdomen appear early in pregnancy; even before displacement from the enlarging uterus. In the first trimester, the subcostal angle changes from 68 to 103°, the diaphragm rises by up to 4 cm and the chest diameter increases by 2 cm or more, diaphragmatic excursion increases by up to 2 cm (the result is "barrel chested" appearance)[8].

Therefore,pro-

woman can be difficult, and smaller endotracheal tubes may be needed[6, 8]..

intestinal tract, predisposing the patient to aspiration of stomach contents [9].

patients was 8.5 × 100,000, with a survival rate of only 59% in the mother [4].

second trimester, and then, remain relatively constant until delivery.

situations of cardiac arrest[3].

30 Resuscitation Aspects

and systemic blood pressure [7].

diopulmonary resuscitation [6].

**2. Changes physiologic in the mother**

It is necessary to know the possible etiology of cardiac arrest in pregnant women to identify and treat correctly the causal factors and therefore give the mother and the fetus a better chance of survival. The cause of maternal cardiac arrest can often be multifactorial, and in many cases it is associated with chronic health problems that exist before pregnancy, so women with comorbidities should have multidisciplinary follow-up. Even so, it must be taken into account that cardiorespiratory arrest (CRA) in pregnant women occurs frequently in previously healthy woman in relation to hemorrhage or embolism (nonarrhythmogenic causes, unlike non-pregnant women). This refers to the non-pulsed electrical activity algorithm (AESP) in which the modified 5H and 5T must be remembered (see **Table 1**) [4, 10**–**15].


**Table 1.** Etiologies of maternal arrest (5H-5T) [11–15].

The main causes of CRA in pregnant women include bleeding, heart failure, sepsis, and amniotic fluid embolism, and the main causes of mortality in this population are the cardiac disease, sepsis, preeclampsia/eclampsia, hemorrhage, cerebrovascular events, amniotic fluid embolism, complications from anesthesia, and thrombosis/thromboembolism [4, 10]. A way to remember those causes is the mnemonic of the American Heart Association (AHA), because the obstetrics' CRA causes are different from the general population [5] (see **Table 2**).


**Table 2.** Etiologies of maternal arrest (A to H's mnemonic) [5].

### **4. Management**

The main causes of CRA in pregnant women include bleeding, heart failure, sepsis, and amniotic fluid embolism, and the main causes of mortality in this population are the cardiac disease, sepsis, preeclampsia/eclampsia, hemorrhage, cerebrovascular events, amniotic fluid embolism, complications from anesthesia, and thrombosis/thromboembolism [4, 10]. A way to remember those causes is the mnemonic of the American Heart Association (AHA), because the obstetrics' CRA causes are different from the general population [5]

> High neuraxial block Hypotension Loss of airway Aspiration

Respiratory depression Local anesthetic systemic toxicity

Retained products of conception

Trauma Suicide

Uterine atony Placenta accreta Placental abruption Placenta previa

Uterine rupture Surgical

Aortic dissection Cardiomyopathy Arrhythmias Valve disease

Drug error Illicit drugs Anaphylaxis

Transfusion reaction

Congenital heart disease

Pulmonary embolus Cerebrovascular event Venous air embolism

HELLP syndrome Intracranial bleed

(see **Table 2**).

32 Resuscitation Aspects

A Anesthetic

Accidents

**Letter Meaning Etiology**

**B** Bleeding Coagulopathy

**C** Cardiovascular Myocardial infarction

E Embolic Amniotic fluid embolus

F Fever Infection/sepsis G General H's and T's (**Table 1**) H Hypertension Preeclampsia-eclampsia

**Table 2.** Etiologies of maternal arrest (A to H's mnemonic) [5].

D Drugs Oxytocin-magnesium-opioids-insulin

The management of CRA in pregnant women should ideally be performed by trained individuals, with knowledge of the physiological changes in pregnancy, in the centers where the equipments necessary for cesarean perimortem and for neonatal resuscitation are available. The most important pillar in the management of CRA in pregnant women is prevention [5], guaranteeing adequate oxygenation, and circulatory volume, so it is recommended to place the patient in a position of complete left lateral decubitus to relieve the aortocava compression, administration of 100% oxygen by face mask to treat or prevent hypoxemia, establish intravenous access above the diaphragm to ensure intravenous therapy is not obstructed by the pregnant uterus and to investigate and treat precipitating factors [11].In the CRA there is basic and advanced management, first the basic management of pregnant women in CRA and then the advanced management will be discussed, emphasizing the changes with respect to the CRA of the non-pregnant adult.

### **4.1. Basic cardiovascular life support**

the basic life support (BLS), the first responders must initiate usual resuscitation measures, including board placement, and provision of chest compressions and appropriate airway management, defibrillation where appropriate, and manual left uterine displacement [12](algorithm N1). A minimum of four responders must be present to carry out all tasks effectively (**Figure 1**).

### *4.1.1. Circulation*

*Thoracic compressions*: the patient should be placed supine for chest compressions (chest compressions performed with the patient in a tilt could be significantly less effective than those performed with the patient in the usual supine position, and this could have a major impact on the chance of successful resuscitation), which must be effective at least 5 cm deep, are performed 3 cm above the traditional sternal point, frequently at least 100 per min and with a sequentiality of 30 chest compressions: 2 artificial ventilation, deviation of the uterus to the left manually, it is recommended to allow complete thoracic expansion after each compression and to minimize interruptions in chest compressions. Once a device has been placed the compressions can be continuous and not alternate with the ventilation [10–12]. There is no literature examining the use of mechanical chest compressions in pregnancy, and this is not advised at this time. Previous guidelines recommended placing the hands slightly higher on the sternum in the pregnant patient, but there are no scientific data to support this recommendation.

### *4.1.2. Airway*

After placing the pregnant woman in a suitable position, the opening of the airway is performed, head extension maneuver is performed, neck flexion and chin elevation (except in patients with a history of cervical trauma, in which if only the lower jaw is raised), if there is

**Figure 1.** Basic life support (BLS)—cardiac arrest in pregnancy.

no response, be prepared to ensure the airway definitively, initiate with pre-oxygenation of the patient with 100% FiO<sup>2</sup> , due to the complications in the pregnant patient because of the physiological changes of the pregnancy. It is recommended to perform this procedure with personnel having greater training in airways, it is recommended to have the "STUBBY" (shorthandled) laryngoscope for mammary hypertrophy, and to have on hand a difficult airway equipment with elements such as mask Laryngeal in case conventional intubation is not possible. It is recommended to make only one attempt and ask for help from the most qualified personnel, if you are in second or third level of care, request help from the anesthesiology group.

#### *4.1.3. Defibrillation*

Identify the defibrillator of your workplace and identify if it is biphasic or monophasic. In the absence of a biphasic defibrillator, it is acceptable to use a single-phase, so far has not shown any injury to the fetus by defibrillation. Defibrillary Cardiopulmonary Arrest (CPA) Rates: We recommend the administration of 200 J by a biphasic defibrillator or 360 J by a single-phase defibrillator in ventricular fibrillation and non-pulse ventricular tachycardia, alternating with the administration of the following drugs: Adrenaline 1 mg IV every 3 min [10**–**14].The energy required for defibrillation during cardiac arrest in pregnancy would be the same as the most current recommendations for the non-pregnant patient.

### **5. Advanced cardiovascular life support**

Although current guidelines for management of CPA adults say that chest compressions should not be interrupted initially for ventilation or airway placement. The pregnant patient has a very limited oxygen reserve and requires early attention to airways and ventilation.

In the advanced cardiovascular life support (ACLS), it is recommended that endotracheal intubation should be performed by an experienced laryngoscopist (not more than two laryngoscopy attempts should be made and prolonged intubation attempts should be avoided to prevent deoxygenation, prolonged interruption in chest compressions, airway trauma, and bleeding), and starting with an endotracheal tube with a 6.0–7.0 mm inner diameter is recommended, because the glottis in pregnancy is often smaller for edema. The cricoid pressure is not routinely recommended, but, continuous waveform capnography, in addition to clinical assessment, is recommended as the most reliable method of confirming and monitoring correct placement of the endotracheal tube (**Figure 2**).

If attempts at airway control fail and mask ventilation is not possible, current guidelines for emergency invasive airway should be followed.

Given the lethality of cardiopulmonary arrest, the benefits from use outweigh any possible fetal risks. All medications at the same doses for treatment of cardiopulmonary arrest in the non-pregnant patient are used for the pregnant patient (**Table 3**).

### **5.1. Arrhythmia-specific therapy during cardiac arrest**

### *5.1.1. Cardiopulmonary non-defibrillation rhythms*

In case of asystole and pulseless electrical activity, focus on chest compressions as well as drug administration. Other potentially lethal arrhythmias that should be treated.

### *5.1.2. Ventricular tachycardia with pulse*

no response, be prepared to ensure the airway definitively, initiate with pre-oxygenation of

physiological changes of the pregnancy. It is recommended to perform this procedure with personnel having greater training in airways, it is recommended to have the "STUBBY" (shorthandled) laryngoscope for mammary hypertrophy, and to have on hand a difficult airway equipment with elements such as mask Laryngeal in case conventional intubation is not possible. It is recommended to make only one attempt and ask for help from the most qualified personnel, if you are in second or third level of care, request help from the anesthesiology group.

Identify the defibrillator of your workplace and identify if it is biphasic or monophasic. In the absence of a biphasic defibrillator, it is acceptable to use a single-phase, so far has not shown any injury to the fetus by defibrillation. Defibrillary Cardiopulmonary Arrest (CPA) Rates: We recommend the administration of 200 J by a biphasic defibrillator or 360 J by a single-phase defibrillator in ventricular fibrillation and non-pulse ventricular tachycardia, alternating with

, due to the complications in the pregnant patient because of the

the patient with 100% FiO<sup>2</sup>

34 Resuscitation Aspects

**Figure 1.** Basic life support (BLS)—cardiac arrest in pregnancy.

*4.1.3. Defibrillation*

Stable monomorphic VT with adult pulse responds well to biphasic or monophasic (synchronized) cardioversion discharges at initial doses of 100 J. If there is no adequate response after the first discharge, it is reasonable to increase the dose in a staggered manner.

### *5.1.3. Supraventricular paroxysmal tachycardia*

In addition to synchronous cardioversion, adenosine is also recommended as a safe and potentially effective drug. There are no data yet on pregnancy. The recommended initial

**Figure 2.** Advanced cardiovascular life support (ACLS)—cardiac arrest in pregnancy.



**Table 3.** Medications used in CPA and its consequences in pregnancy.

**Medications Use Adverse effects Observations Dose**

**Figure 2.** Advanced cardiovascular life support (ACLS)—cardiac arrest in pregnancy.

Reduce uterine blood flow through alpha-adrenergicmediated blood vessel vasoconstriction

Uterine contractions Is not clearly superior

Magnesium toxicity Should be

to epinephrine

discontinued Calcium chloride (10 mL of a 10% solution) or calcium gluconate (30 mL of a 10% solution) intravenously or intraosseously

Is superior 1 mg IV every 3–5 min

> Is not recommended

g IV/h

4 or 6 g IV, followed by a maintenance 1–2

Epinephrine If VF or VT persists

Vasopressin Was removed from the

for CPA

Magnesium sulfate Pregnancy

36 Resuscitation Aspects

after at least one attempt at defibrillation and 2 min of CPA

treatment algorithm

• Prevention of eclamptic seizures • Fetal neuroprotection before preterm

delivery

biphasic energy dose for synchronous cardioversion of atrial fibrillation is 120–200 J. The initial monophasic dose for synchronous cardioversion of atrial fibrillation is 200 J. In general, atrial flutter cardioversion and other supraventricular rhythms require less energy. An initial energy of 50–100 J with a single-phase or biphasic device is usually sufficient. If the first discharge of the cardioversion fails, the dose should be increased stepwise.

### **6. Modifications of the basic support and advanced cardiac life support in pregnancy**

The three major modifications during the pregnant patient CPR are given in below sections.

### **6.1. Shift of the uterus to the left at 15–30° and upward during chest compressions**

To improve placental perfusion and enable a perimortem cesarean, it has been described that thoracic compressions in non-pregnant patients produce 30% of the CG, to which 25% more is added by applying the lateralization of the uterus to the left. For this purpose, a blanket can be placed under the right hip or the Cardiff resuscitation wedge, which maintains the patient in the left dorsal decubitus position at 27° since an inclination greater than 30° has been associated with a significant decrease in force generation during chest compression.

### **6.2. Early endotracheal intubation**

Waive ventilation with bag-mask and proceed directly to endotracheal intubation by the most experienced person, as the physiological changes of pregnancy increase 10 times the risk of complications they put. It is life-threatening mainly because of decreased functional residual capacity (CRF) by compression of the pregnant uterus, resulting in rapid desaturation, as well as edema (often thin tubes are used) and hyperaemia of the upper airway which cause frequent bleeding and make it difficult to visualize the vocal cords, especially in the presence of preeclampsia. In addition, decreased gastric motility and relaxation of esophageal sphincter tone increase the risk of aspiration. For all of the above, it is also recommended the use of muscle relaxants and rapid intubation sequence (SIR), as well as nasogastric tube placement (SNG) [12**–**14].

### **6.3. Cesarean perimortem**

Cesarean perimortem is defined as the birth of the fetus after maternal cardiac arrest. Birth is almost always accomplished through cesarean delivery, but assisted vaginal delivery is appropriate if the cervix is fully dilated and the neonate is at a low station and can be delivered within 5 min of maternal cardiorespiratory collapse [15]. A review of published cases up to 2010 has showed that the cesarean perimortem led to a clear maternal survival benefit 31.7% [16].

The purpose of the cesarean perimortem is twofold. The first is facilitation of resuscitation, relieving aortocaval compression by emptying the uterus significantly improves resuscitative efforts. Second, early delivery of the baby, is accomplished with a decreased risk of permanent neurological damage from anoxia.

It is contemplated within the "four-five rule" of obstetric stop, which consists of starting the cesarean section 4 min after the maternal cardiac arrest so that he drinks be born within 5 min after the arrest spontaneous circulation and not later, especially when the cause is irreversible (e.g. abrupt), which in turn improves the maternal GC by 30% with autotransfusion of 500 ml. It is the most important consideration in the OP. According to Katz, 71% of babies surviving maternal cardiorespiratory arrest with good neurologic outcome were removed in 5 min or less. Therefore, fetal extraction is considered as the "D" of cardiopulmonary resuscitation in the pregnant woman.

Sudden substantial improvement in hemodynamics with a return of pulse and blood pressure immediately after perimortem cesarean delivery has been observed.

There are three pathophysiological states (in relation to the uterus and navel): O Pregnancy < 20 weeks, AU below navel: impaired hemodynamic compromise for the mother by the uterus, non-viable baby. No benefit of cesarean perimortem.

Or pregnancy of 20–23 weeks, AU up to 3 cm above the navel: possible hemodynamic involvement of the mother by the uterus, probably not viable baby. Consider cesarean perimortem to save the life of the mother.

O pregnancy ≥ 24 weeks, AU at 4 cm above the navel: possible hemodynamic compromise exerted by the uterus, cesarean section perimortem is indicated during cardiopulmonary arrest to benefit the mother as well as the fetus. Consider not closing the abdominal incision if cesarean section was necessary, to bind blood vessels as well as reduce the possibility of an abdominal compartment syndrome [2, 3, 6–10].

If the cesarean perimortem could not be performed by the 5-min mark, it was still advisable to prepare to evacuate the uterus while the resuscitation continued, infant survival has been seen even when delivery occurred > 5 min from the onset of maternal cardiac arrest. Neonatal survival was documented even when delivery occurred up to 30 min after the onset of maternal cardiac arrest [17]. The procedure should be performed at the site of the maternal resuscitation. Time should not be wasted in moving the patient or waiting for surgical equipment or doing abdominal preparation [18]. The only equipment needed to start is a scalpel[5].

### **7. Other considerations**

**6.2. Early endotracheal intubation** 

38 Resuscitation Aspects

**6.3. Cesarean perimortem** 

nent neurological damage from anoxia.

Waive ventilation with bag-mask and proceed directly to endotracheal intubation by the most experienced person, as the physiological changes of pregnancy increase 10 times the risk of complications they put. It is life-threatening mainly because of decreased functional residual capacity (CRF) by compression of the pregnant uterus, resulting in rapid desaturation, as well as edema (often thin tubes are used) and hyperaemia of the upper airway which cause frequent bleeding and make it difficult to visualize the vocal cords, especially in the presence of preeclampsia. In addition, decreased gastric motility and relaxation of esophageal sphincter tone increase the risk of aspiration. For all of the above, it is also recommended the use of muscle relaxants and rapid

Cesarean perimortem is defined as the birth of the fetus after maternal cardiac arrest. Birth is almost always accomplished through cesarean delivery, but assisted vaginal delivery is appropriate if the cervix is fully dilated and the neonate is at a low station and can be delivered within 5 min of maternal cardiorespiratory collapse [15]. A review of published cases up to 2010 has showed that the cesarean perimortem led to a clear maternal survival benefit 31.7% [16].

The purpose of the cesarean perimortem is twofold. The first is facilitation of resuscitation, relieving aortocaval compression by emptying the uterus significantly improves resuscitative efforts. Second, early delivery of the baby, is accomplished with a decreased risk of perma-

It is contemplated within the "four-five rule" of obstetric stop, which consists of starting the cesarean section 4 min after the maternal cardiac arrest so that he drinks be born within 5 min after the arrest spontaneous circulation and not later, especially when the cause is irreversible (e.g. abrupt), which in turn improves the maternal GC by 30% with autotransfusion of 500 ml. It is the most important consideration in the OP. According to Katz, 71% of babies surviving maternal cardiorespiratory arrest with good neurologic outcome were removed in 5 min or less. Therefore, fetal extraction is considered as the "D" of cardiopulmonary resuscitation in the pregnant woman.

Sudden substantial improvement in hemodynamics with a return of pulse and blood pressure

There are three pathophysiological states (in relation to the uterus and navel): O Pregnancy < 20 weeks, AU below navel: impaired hemodynamic compromise for the mother by the uterus,

Or pregnancy of 20–23 weeks, AU up to 3 cm above the navel: possible hemodynamic involvement of the mother by the uterus, probably not viable baby. Consider cesarean perimortem to

O pregnancy ≥ 24 weeks, AU at 4 cm above the navel: possible hemodynamic compromise exerted by the uterus, cesarean section perimortem is indicated during cardiopulmonary arrest to benefit the mother as well as the fetus. Consider not closing the abdominal incision

immediately after perimortem cesarean delivery has been observed.

non-viable baby. No benefit of cesarean perimortem.

save the life of the mother.

intubation sequence (SIR), as well as nasogastric tube placement (SNG) [12**–**14].


### **Author details**

Daniel Molano Franco1 \* and María Velez Maya2

\*Address all correspondence to: dalemofra@gmail.com

1 Gynecology and Obstetric, Intensive Care Medicine University Clinic Colombia, Bogotá, Colombia

2 Gynecology and Obstetrics, University National of Colombia, Bogotá, Colombia

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[2] Neumar RW, Otto CW, Link MS, et al. Part 8: Adult advanced cardiovascular life support: 2010 American Heart Association guidelines for cardiopulmonary resuscitation

[3] Trends in maternal mortality: 1990 to 2013. Estimates by WHO, UNICEF, UNFPA, the World Bank and the United Nations Population Division. Geneva (Switzerland): World

[4] Mhyre JM, Tsen LC, Einav S, et al. Cardiac arrest during hospitalization for delivery in

[5] Jeejeebhoy FM, Zelop CM, Lipman S, et al. Cardiac arrest in pregnancy: A scientific statement from the American Heart Association. Circulation. 2015;**132**:1747-1773 [6] Tan EK, Tan EL. Alterations in physiology and anatomy during pregnancy. Best practice & research. Clinical Obstetrics & Gynaecology. 2013;**27**:791-802. DOI: 10.1016/j. bpob-

[7] Melchiorre K, Sharma R, Thilaganathan B. Cardiac structure and function in normal

[8] Hegewald MJ, Crapo RO. Respiratory physiology in pregnancy. Clinics in Chest

[9] Carlin A, Alfirevic Z. Physiological changes of pregnancy and monitoring. Best practice

[10] Belfort M, Saade G, Foley M, Phelan J, Dildy G, editors. Critical Care Obstetrics. 5th ed.

[11] Campbell JP, Bushby D, Yentis SM. Cardiopulmonary resuscitation in the pregnant patient: A manikin-based evaluation of methods for producing lateral tilt. Anaesthesia.

[12] Gabbott DA. Uterine displacement during CPR in the pregnant patient-why bother?

[13] Ezri T, Lurie S, Weiniger CF, Golan A, Evron S. Cardiopulmonary resuscitation in the pregnant patient—An update. The Israel Medicine Association Journal. 2011;**13**(5):306-310 [14] Saenz-Madrigal ME, Vindas-Morera CA. Paro cardiaco en el embarazo. Revista

[15] Dijkman A, Huisman CM, Smit M, et al. Cardiac arrest in pregnancy: Increasing use of perimortem caesarean section due to emergency skills training? British Journal of

[16] Einav S, Kaufman N, Sela HY. Maternal cardiac arrest and perimortem caesarean delivery: Evidence or expert-based? Resuscitation. 2012;**83**:1191-1200. DOI: 10.1016/j.

[17] Katz V, Balderston K, DeFreest M. Perimortem cesarean delivery: Were our assumptions

correct? American Journal of Obstetrics & Gynecology. 2005;**192**:1916-1920

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& research. Clinical Obstetrics & Gynaecology. 2008;**22**(5):801-823

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**Provisional chapter**

## **Should Family be Allowed During Resuscitation**

**Should Family be Allowed During Resuscitation**

DOI: 10.5772/intechopen.70189

### Abbas Al Mutair Abbas Al Mutair Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.70189

### **Abstract**

The practice of family presence during resuscitation provides the opportunity to the family members to attend visually and physically with the patient during resuscitation. The concept of family presence during resuscitation empowers the family-centred care philosophy. However, allowing families during resuscitation is controversial among health care providers. Using predefined search terms, a systematic search was carried out on CINAHL, PubMed, Proquest, Meditext, Ebsco and MedLine. Of the references identified, 35 studies were identified that met the inclusion criteria. The included studies clearly highlight. The family members revealed a desire to their presence during resuscitation and indicated further benefits of their presence. Health care providers had different opinions, some refused the practice indicating that it would be offensive and may interfere with the treatment. Others believed that it would positively affect patient care and would reassure family that the best care is being provided. Both family members and health care providers showed a need for educational programs and written policies to facilitate family presence during resuscitation.

**Keywords:** resuscitation, presence during resuscitation, family witnesses resuscitation, relatives, health professionals

### **1. Introduction**

The idea of allowing family members to be present during resuscitation began at the Foote Hospital in Michigan in the United States of America in 1983 [1, 2]. This was when two family members refused to leave their loved one during resuscitation and asked to be with them even for few minutes to offer what they could during such a crisis event. The American Emergency Nurses Association in 1993 was the first professional organisation to develop evidence-based written guidelines endorsing the practice of family presence during resuscitation [3]. Over the years, the option for relatives to be present during resuscitation has been highly recommended by a number of medical organisations throughout the world.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Family presence during resuscitation is an important topic and of current debate among health care professionals. The literature has shown that attitudes of nurses, physicians and families towards family presence were found to be significantly different [4, 5]. Some health care providers feared that family members may end up having traumatic memories of the practice [6], whereas many family members indicated they would prefer to remain with the patient [4]. Physicians were found to be more against family presence during resuscitation than were nurses [7–9].

Many health care organisations, including the American Association of Critical-Care Nurses, American Heart Association, Emergency Nurses Association, Canadian Association of Critical Care Nurses, Royal College of Nursing, British Association for Accident and Emergency Medicine, European Federation of Critical Care Nursing Associations, European Society of Paediatric and Neonatal Intensive Care and European Society of Cardiology Council on Cardiovascular Nursing and Allied Professions have issued statements that family members of patients undergoing resuscitation should be given the option to remain during the procedure [3, 10–12].

### **2. Search strategy**

An electronic comprehensive search of resulting references was conducted on CINAHL, PubMed, Proquest, Meditext, Ebsco and MedLine using the words 'family presence during resuscitation', 'health professionals', 'nurses' with 'family witnesses resuscitation', 'relatives' and 'resuscitation'. Articles were included only if the manuscript was published in a peer-reviewed journal and was based on an empirical study. The quality of the studies included in the review was appraised using Polit and Beck guide to critique research articles asking questions on the report of the research process to determine whether the findings are usable and of good quality [13]. Questions were on study purpose, research design, literature review, research question/hypothesis, study sample, data collection, study results and study recommendations (refer to **Table 1**).



**Table 1.** Polit and Beck guide to critique research articles.

Family presence during resuscitation is an important topic and of current debate among health care professionals. The literature has shown that attitudes of nurses, physicians and families towards family presence were found to be significantly different [4, 5]. Some health care providers feared that family members may end up having traumatic memories of the practice [6], whereas many family members indicated they would prefer to remain with the patient [4]. Physicians were found to be more against family presence during resuscitation than were nurses [7–9].

Many health care organisations, including the American Association of Critical-Care Nurses, American Heart Association, Emergency Nurses Association, Canadian Association of Critical Care Nurses, Royal College of Nursing, British Association for Accident and Emergency Medicine, European Federation of Critical Care Nursing Associations, European Society of Paediatric and Neonatal Intensive Care and European Society of Cardiology Council on Cardiovascular Nursing and Allied Professions have issued statements that family members of patients undergoing resuscitation should be given the option to remain during the procedure [3, 10–12].

An electronic comprehensive search of resulting references was conducted on CINAHL, PubMed, Proquest, Meditext, Ebsco and MedLine using the words 'family presence during resuscitation', 'health professionals', 'nurses' with 'family witnesses resuscitation', 'relatives' and 'resuscitation'. Articles were included only if the manuscript was published in a peer-reviewed journal and was based on an empirical study. The quality of the studies included in the review was appraised using Polit and Beck guide to critique research articles asking questions on the report of the research process to determine whether the findings are usable and of good quality [13]. Questions were on study purpose, research design, literature review, research question/hypothesis, study sample, data collection, study results and study recommendations (refer to **Table 1**).

Will the study improve practice and add to the body of the knowledge?

If there is no framework/theory, is it clear to identify? How the data were collected?

**2. Search strategy**

44 Resuscitation Aspects

Research question/ hypothesis

**Critique element Questions to be asked** Study purpose Is the purpose clear?

Is it relevant to the practice?

Is the literature review current?

How large is the sample?

What is the plan for conducting the study?

Is the literature review well organised?

Are the majority of sources primary or secondary?

Is the research question/hypothesis clearly stated?

How often data was collected and for how long? What instruments or tools were used? Is the tool valid and reliable?

Were data analysis procedure appropriate?

Does the question/hypothesis match the purpose of the study?

Research design Is there a framework/theory to guide the study?

Who will be studied?

Literature review Is the literature review comprehensive?

Study sample How were the sample chosen?

Data collection What steps taken to collect data?

**Figure 1.** Literature review flow diagram.

As a result of the search, 62 articles were retrieved that were published between 1982 and 2016. These publications were mainly research reports, discussion and review papers. Most of the studies were descriptive and mainly used a quantitative approach to identify family presence during resuscitation and other invasive procedures [12, 14]. Fewer studies used an experimental design or qualitative approach. The majority of those studies were American in origin; however, some were Canadian, British, Swedish, Norwegian, Chinese, Icelandic, French, Australian, Turkish, Jordanian and German. In total, 32 English language publications were selected for this review. The excluded studies were either of poor quality or did not meet the inclusion criteria. This sample (*n* = 32) included seven papers that were published following the definition and initial development of family presence during resuscitation. A larger sample of 25 more recently published papers between 1990 and 2016 was included to represent the different perspectives of family presence during resuscitation (**Figure 1**). The attitudes of family members during resuscitation as perceived by family members will be discussed, followed by the attitude of health care providers towards the practice. However, before proceeding, the benefits of family presence during resuscitation are addressed.

### **3. Benefits of family presence**

The benefits of family presence during resuscitation include several factors [7, 15, 16].


### **4. Family attitudes to family presence**

The presence of family members during resuscitation can help them to face the reality of the situation and support the critically ill patient. Much of the literature has examined the attitudes of the family members towards their presence during resuscitation, but has neglected to explore the psychological effects of the practice on the family members.

In 1998, a small retrospective survey study took place at an inner-city teaching hospital in London [17]. The study was to assess the family members' desire to be present and to determine their knowledge of what was involved in the resuscitation process. Thirty-five family members who were not present during the resuscitation were asked to complete a questionnaire 3 months after their loved one's death. The findings suggested that only 4 (11%) of the 35 family members were given the option to be present during the resuscitation. Interestingly, of the total sample, 62% of family members would have chosen to be present during the resuscitation attempt if they had been given the option. This study indicated that most of the participating family members did not have an accurate idea of what occurred during the procedure. Therefore, their inclusion may have had a positive impact by knowing that everything possible was done to save their loved one. Family members of patients who survived were not included in the study and their inclusion would have added depth and enriched the study findings.

meet the inclusion criteria. This sample (*n* = 32) included seven papers that were published following the definition and initial development of family presence during resuscitation. A larger sample of 25 more recently published papers between 1990 and 2016 was included to represent the different perspectives of family presence during resuscitation (**Figure 1**). The attitudes of family members during resuscitation as perceived by family members will be discussed, followed by the attitude of health care providers towards the practice. However,

before proceeding, the benefits of family presence during resuscitation are addressed.

The benefits of family presence during resuscitation include several factors [7, 15, 16].

**2.** Family presence helps nurses to provide more holistic care.

**1.** It assists in obtaining the patient's history quickly, thereby actively supporting the patient.

**3.** Family presence encourages more professional behaviour among staff during resuscitation.

**6.** The family presence during resuscitation and other invasive procedures reduces family

**7.** It is easier to manage family members when they are present in the room with the patient. **8.** It enables family members to recognise that everything possible is being done to save the

**9.** Family presence allows the opportunity for family members to say goodbye to their loved

The presence of family members during resuscitation can help them to face the reality of the situation and support the critically ill patient. Much of the literature has examined the attitudes of the family members towards their presence during resuscitation, but has neglected

In 1998, a small retrospective survey study took place at an inner-city teaching hospital in London [17]. The study was to assess the family members' desire to be present and to determine their knowledge of what was involved in the resuscitation process. Thirty-five family members who were not present during the resuscitation were asked to complete a questionnaire 3 months after their loved one's death. The findings suggested that only 4 (11%) of the 35 family members were given the option to be present during the resuscitation. Interestingly, of the total sample, 62% of family members would have chosen to be present during the

to explore the psychological effects of the practice on the family members.

**4.** It strengthens the link between nurses and families and alleviates many of the doubts. **5.** It provides an opportunity to educate the family about the condition of the patient.

**3. Benefits of family presence**

anxiety and fear.

one when death occurs.

**4. Family attitudes to family presence**

patient.

46 Resuscitation Aspects

In the same year, Meyers et al. [18] completed a retrospective survey study of 25 family members who were not present during resuscitation, regarding their attitudes towards the practice. The participants were interviewed via telephone within 8 weeks to 15 months after the patient's death; all patients had received resuscitation and died within 1 h after admission to the hospital and 95% of the patients' deaths were caused by traumatic injury. The findings here revealed that 80% of family members who were surveyed indicated their desire to be with their loved one during resuscitation; 96% believed that they had the right to be present; 68% believed that their presence would have helped the patient and 64% felt their presence would have helped their sorrow following the death of their loved one. Regardless of the long period between the death of the family member and the data collection, the family members confirmed the benefit to the patient and family members and supported the option of being present [17, 18].

The third study which was a randomised controlled trial conducted in an Emergency Department (ED) in Cambridge, United Kingdom [15]. The study concerned the psychological effect on 18 family members who witnessed the resuscitation of their family member. The family members of patients who required resuscitation were divided into two groups: the first was the family members who were given the option to remain during the resuscitation (*n* = 8). The second was the family members who were not given the option to remain during the resuscitation (*n* = 10). The relatives were asked to complete five standardised psychological questionnaires within 1–6 months after the resuscitation. The small sample size and the criteria for subjects which were not provided in the article, have constrained the study findings. The findings showed that relatives who witnessed the resuscitation had lower levels of anxiety, intrusive imagery, depression and grief than did those who did not witness the resuscitation. No family members in the group reported being frightened or had to be asked to leave the room. The routine exclusion of family members from the resuscitation room may not be appropriate because family presence provides a means of expression for grieving family members.

Researchers using mixed methods surveyed family members to investigate their attitudes towards family presence during resuscitation and other invasive procedures [4]. They surveyed 39 family members, following 19 instances of family presence during resuscitation and 24 invasive procedures. The study indicated that all participating family members ascribed benefits in attending resuscitation. They added that for the families of dying patients, family presence afforded the opportunity to say goodbye and come to closure on a shared life for people who believed being with the patient was their right. Family members involved in resuscitation viewed themselves as 'active participants' in the care process, which met their needs for knowing about providing comfort and support for their loved one. All the participating family members surveyed in this study believed that visitation was helpful to them and noted that they would do it again. Also, almost all participants said they thought it was their right to be present with their loved one, and most importantly follow-up did not show they suffered from traumatic effects. They added that other benefits for the family included knowing that everything possible had been done, reducing their anxiety and fear and easing their bereavement. A strong bias can clearly be identified in the data collection, family members who accepted visitation during resuscitation or other invasive procedures were included in the study while those who refused it were excluded.

Differently from the previous studies, six family members whose loved ones underwent resuscitation and survived were interviewed within 24 h of the resuscitation [19]. This study was conducted in the Coronary Care Unit in a 700-bed urban community hospital in north eastern Ohio. The participants were adult family members and they were asked to describe the experiences, thoughts and perceptions of their critically ill relative during resuscitation in the ICU. The interviews showed that the family members were barred from the patients' room and asked to wait in another room. They struggled with the question of 'should we go or should we stay'. The author added that 'families lose autonomy and do not gain ground when they attempt to negotiate their way into the resuscitation room' (p. 417) [19]. The study concludes that when families are not provided information during resuscitation they cannot determine what is going on. Also, during the resuscitation of the loved one, the family is in crisis and needs reassurance and informational support to cope effectively. The study had a small sample size due to the exclusion of families whose relative underwent resuscitation and died. Although this exclusion criterion is understandable, it had influence on the power of the study as those members may have opinions and concerns to share that could have enriched to the study findings.

A randomised control trial design was used to study the attitudes of family members who were present during resuscitation [16]. The study was carried out by the researchers in a major tertiary referral teaching hospital in Queensland, Australia. Family members meeting the inclusion criteria were randomised to either the control group or experimental group. The control group (*n* = 40) did not attend the procedure and remained out of the resuscitation room. The experimental group (*n* = 58) were invited to the resuscitation room during resuscitation. A questionnaire was developed to gather the data for the study based on clinical staff experience and review of literature. The findings showed that the majority of family members in both the control and experimental group were grateful to be present during the resuscitation of their loved one. None of the participants felt pressured or traumatised to be present and 43% preferred to be present. Sixty-seven per cent of control group participants preferred to be present. Furthermore, in this study all of the family members who were present during resuscitation (experimental group) were glad that they were present to support their relative. The vast majority of the experimental group participants agreed that their presence during resuscitation helped them to come to terms with the patient's outcomes. Of the control group, 71.2% thought their presence would have helped them to cope better with their loved one's outcome. Participants in the experimental group (85%) felt their presence was beneficial to the patient's recovery. The findings of this research strongly support the presence of family during resuscitation, and have several clinical implications.

### **5. Healthcare providers' attitudes to family presence**

and noted that they would do it again. Also, almost all participants said they thought it was their right to be present with their loved one, and most importantly follow-up did not show they suffered from traumatic effects. They added that other benefits for the family included knowing that everything possible had been done, reducing their anxiety and fear and easing their bereavement. A strong bias can clearly be identified in the data collection, family members who accepted visitation during resuscitation or other invasive procedures were included

Differently from the previous studies, six family members whose loved ones underwent resuscitation and survived were interviewed within 24 h of the resuscitation [19]. This study was conducted in the Coronary Care Unit in a 700-bed urban community hospital in north eastern Ohio. The participants were adult family members and they were asked to describe the experiences, thoughts and perceptions of their critically ill relative during resuscitation in the ICU. The interviews showed that the family members were barred from the patients' room and asked to wait in another room. They struggled with the question of 'should we go or should we stay'. The author added that 'families lose autonomy and do not gain ground when they attempt to negotiate their way into the resuscitation room' (p. 417) [19]. The study concludes that when families are not provided information during resuscitation they cannot determine what is going on. Also, during the resuscitation of the loved one, the family is in crisis and needs reassurance and informational support to cope effectively. The study had a small sample size due to the exclusion of families whose relative underwent resuscitation and died. Although this exclusion criterion is understandable, it had influence on the power of the study as those members may have opinions and concerns to share that could have enriched

A randomised control trial design was used to study the attitudes of family members who were present during resuscitation [16]. The study was carried out by the researchers in a major tertiary referral teaching hospital in Queensland, Australia. Family members meeting the inclusion criteria were randomised to either the control group or experimental group. The control group (*n* = 40) did not attend the procedure and remained out of the resuscitation room. The experimental group (*n* = 58) were invited to the resuscitation room during resuscitation. A questionnaire was developed to gather the data for the study based on clinical staff experience and review of literature. The findings showed that the majority of family members in both the control and experimental group were grateful to be present during the resuscitation of their loved one. None of the participants felt pressured or traumatised to be present and 43% preferred to be present. Sixty-seven per cent of control group participants preferred to be present. Furthermore, in this study all of the family members who were present during resuscitation (experimental group) were glad that they were present to support their relative. The vast majority of the experimental group participants agreed that their presence during resuscitation helped them to come to terms with the patient's outcomes. Of the control group, 71.2% thought their presence would have helped them to cope better with their loved one's outcome. Participants in the experimental group (85%) felt their presence was beneficial to the patient's recovery. The findings of this research strongly support the presence of family during

in the study while those who refused it were excluded.

resuscitation, and have several clinical implications.

to the study findings.

48 Resuscitation Aspects

The health care providers' behaviours towards family members often affect the family members' decision to be present or leave during the resuscitation. In 2000, three studies of health professional attitudes towards family presence during resuscitation were released using a survey design, which was conducted in three different contexts throughout the world. A retrospective study was conducted in a university-affiliated level I trauma centre [7]. The authors surveyed a total of 96 medical staff; 14 physicians, 22 residents and 60 nurses, who had participated in resuscitation or an invasive procedure with family members. The participants were asked to complete a 33-item questionnaire developed for the study within 17 days of the resuscitation or invasive procedure event.

Most of the medical staff (96% of nurses, 79% of physicians and 19% of the residents) favoured family presence during resuscitation. The vast majority (95% of the nurses, 77% of physicians and 64% of the residents) were comfortable with family presence during resuscitation. The study also evaluated the perceived stress of the 96 health care providers who had performed resuscitation efforts with family members present. The majority (84%) believed their performance was unaffected by the family's presence. The study concluded that the provider discomfort and inexperience decreased the likelihood of a supportive family presence. Also, the authors claim that family members should be assessed for their coping abilities and emotional stability before the option of family presence during resuscitation is offered. The study resulted in the development of a policy for family presence during resuscitation. The accuracy of the recollections of the medical staff may be questioned in Meyers et al.'s study [7], because the survey was completed over 2 weeks after the actual event.

In the second study, researchers surveyed 368 members of the American Association for the Surgery of Trauma (AAST) and 1261 Emergency Nurses Association (ENA) members [20]. The study proposed to determine the health care providers' opinion regarding the phase of the trauma resuscitation in which family members should be allowed to be present. The results indicated that only 3% of AAST members' participants, but 59% of ENA members, favoured family presence during resuscitation. The authors concede that the findings were biased by, firstly, the overrepresentation of ENA members, and secondly because the AAST members do not represent ED staff. Similarly to the previous study, the current study suggested the implementation of family presence may cause conflicts and thus impact on the performance of the trauma team [20].

In a third study a retrospective study was conducted in the Accident and Emergency (A&E) Department which took place at Hope Hospital Salford in the United Kingdom [21]. The study included only non-traumatic adult cardio pulmonary resuscitation and was to determine whether the presence of relatives during resuscitation altered perceived symptoms of stress in medical staff. An anonymous structured questionnaire was used to survey 114 medical staff 24 h after participating in resuscitation to obtain symptoms and acute stress reaction based on ICD-10 diagnostic criteria. The results indicated that 25 medical staff reported at least more than two symptoms of acute stress reaction. Of the 25 reporting more than two symptoms, 13 reported with the family being present during resuscitation and 12 without the family being present: there was thus no significant difference between the two groups. The study included only non-traumatic adult resuscitation and excluded the traumatic resuscitation which would have enriched the study findings. The findings here substantiate [7] findings that the presence of relatives witnessing resuscitation did not affect self-reported stress symptoms.

Researchers surveyed 592 health care professionals attending the International Meeting of the American College of Chest Physicians in San Francisco, using a quantitative method [8]. The questionnaire distributed consisted of six questions about family presence practice and resuscitation experience with relatives. The study found that fewer physicians (20%) compared to nurses and allied health care workers combined (39%), would allow family members presence during adult resuscitation. Thus study indicating that the majority of intensive care professionals did not support it. They added that the intensive care professionals' opposition was based on many reasons, which included the fear of psychological trauma to the witnessing family members, performance anxiety among the CPR team, and the distraction of the resuscitation team. However, others believed strongly that the presence of family members in the resuscitation bay would positively affect patient care. An interesting significant relationship of this study was found in that the health care professionals with previous experience of family presence opposed the practice more than those with no experience.

A quantitative descriptive research study was undertaken using a 30-item survey on a random sample of 1500 members of the American Association of Critical-Care Nurses and 1500 members of the ENA [9]. The study sought to identify policies, preferences and practices of critical care and emergency nurses towards family presence during resuscitation and invasive procedures. The survey consisted of 20 items on demographic data, 9 items on practice, preferences and policies and 1 item for comments and experiences of the nurse. A total of 473 intensive care nurses, 465 emergency nurses and 55 nurses who either practised in both areas or did not provide detailed work information participated in the study. The results indicate that nearly all of the 984 respondents had no written policies for family presence during resuscitation and other invasive procedures, and most preferred it to be allowed. Nearly half the participants indicated that they worked in units that allow family presence without written policies. Thirty-seven per cent of the respondents preferred written policies allowing family presence. Furthermore, most intensive care and emergency nurses supported the practice. These findings are consistent with [7] findings. The findings of this study also add to the evidence that health care providers who have experience with family presence tend to support the practice more than those who do not have experience, in contrast to Ref. [8].

These findings are important and have implications for conducting research on this issue in different settings because many nurses receive requests from patients' family members to be present during resuscitation and other invasive procedures and nurses are often the facilitators of the family presence. The study concluded that family presence during resuscitation lacked written policy. The study did not undergo reliability testing and appeared to have no construct validity, also the generalisability of the study is limited to nurses.

Ellison applied a descriptive correlational study with qualitative components to identify the relationship between demographic variables and nurses' attitudes and beliefs regarding family presence during resuscitation or invasive procedures [22]. These demographic variables included educational preparation, specialty certification, experience, completion of a family presence educational offering, age, sex and ethnicity. A total of 208 hospital nurses and New Jersey ENA members completed the questionnaire. The study found a statistically significant difference between positive attitudes towards family presence and higher educational preparation (*r* = 0.216, *P* < 0.01), certification in emergency nursing (*r* = 0.216, *P* < 0.01) and emergency nurse specialisation (*r* = 0.234, *P* < 0.01). These findings support [20] study that certified nurses had more favourable attitudes towards family presence than noncertified nurses.

reported with the family being present during resuscitation and 12 without the family being present: there was thus no significant difference between the two groups. The study included only non-traumatic adult resuscitation and excluded the traumatic resuscitation which would have enriched the study findings. The findings here substantiate [7] findings that the presence

Researchers surveyed 592 health care professionals attending the International Meeting of the American College of Chest Physicians in San Francisco, using a quantitative method [8]. The questionnaire distributed consisted of six questions about family presence practice and resuscitation experience with relatives. The study found that fewer physicians (20%) compared to nurses and allied health care workers combined (39%), would allow family members presence during adult resuscitation. Thus study indicating that the majority of intensive care professionals did not support it. They added that the intensive care professionals' opposition was based on many reasons, which included the fear of psychological trauma to the witnessing family members, performance anxiety among the CPR team, and the distraction of the resuscitation team. However, others believed strongly that the presence of family members in the resuscitation bay would positively affect patient care. An interesting significant relationship of this study was found in that the health care professionals with previous experience of

A quantitative descriptive research study was undertaken using a 30-item survey on a random sample of 1500 members of the American Association of Critical-Care Nurses and 1500 members of the ENA [9]. The study sought to identify policies, preferences and practices of critical care and emergency nurses towards family presence during resuscitation and invasive procedures. The survey consisted of 20 items on demographic data, 9 items on practice, preferences and policies and 1 item for comments and experiences of the nurse. A total of 473 intensive care nurses, 465 emergency nurses and 55 nurses who either practised in both areas or did not provide detailed work information participated in the study. The results indicate that nearly all of the 984 respondents had no written policies for family presence during resuscitation and other invasive procedures, and most preferred it to be allowed. Nearly half the participants indicated that they worked in units that allow family presence without written policies. Thirty-seven per cent of the respondents preferred written policies allowing family presence. Furthermore, most intensive care and emergency nurses supported the practice. These findings are consistent with [7] findings. The findings of this study also add to the evidence that health care providers who have experience with family presence tend to support the practice more than those who do not

These findings are important and have implications for conducting research on this issue in different settings because many nurses receive requests from patients' family members to be present during resuscitation and other invasive procedures and nurses are often the facilitators of the family presence. The study concluded that family presence during resuscitation lacked written policy. The study did not undergo reliability testing and appeared to have no

Ellison applied a descriptive correlational study with qualitative components to identify the relationship between demographic variables and nurses' attitudes and beliefs regarding

construct validity, also the generalisability of the study is limited to nurses.

of relatives witnessing resuscitation did not affect self-reported stress symptoms.

family presence opposed the practice more than those with no experience.

have experience, in contrast to Ref. [8].

50 Resuscitation Aspects

Qualitative findings revealed that personal factors such as experience with crisis situations, ability to manage crisis situations and cultural differences between patients/families and nurses were identified as variables influencing respondents' attitudes towards family presence [22]. Qualitative findings also revealed organisational and social factors that can have a negative impact on nurses' attitudes towards family presence. Working in an environment with supportive colleagues such as those with higher education and specialised training was more likely to bring a change in behaviour. Additionally, nurses found family presence most acceptable when they or their families were patients [22]. Those findings are limited as the data was collected from only one hospital and one professional nursing organisation.

Another descriptive qualitative study was carried out [23]. The study explored nurses' beliefs regarding family presence during resuscitation. The data were gathered from ten Registered Nurses (RNs), one male and nine female with a minimum of 4 years clinical experience working in diverse acute care units through a semi structured interview. The interview consisted of 16 open-ended questions and lasted for 45 min. Certain findings in this study are similar to those in study [7], both studies revealed that families should be assigned with staff due to the possibility of psychological harm to the families; staff feelings of being watched; and increased professional behaviour on the part of the resuscitation team when families are present. The issue of disruption by family members was also raised but authors commented that nearly their entire health care provider sample of 60 RNs and 36 physicians responded that family behaviour towards resuscitation procedures was appropriate [7].

Findings in Refs. [9, 23] differed with respect to participants' views about the need for policies. Participants in Ref. [23] study were not asked to address the issue of having written policies regarding family presence. In contrast, findings from Ref. [9] indicated that most intensive care nurses preferred having policies in place for resuscitation. They also noted that nurses, more than physicians, supported family presence [9]. Family presence is not traditionally practised and it may not be considered, unless brought to the attention of administration by nursing staff committed to change their policy. The study group in current study was small (*n* = 10), the age group was limited to 31–41 years of age and those factors accordingly limited the generalisability of the study findings [23]. Furthermore, the setting of the interview was different for all nurses and this did not allow consistency in the interview process.

The experiences and attitudes of 124 European critical care nurses to the family presence during resuscitation of adult patients were explored [12]. The nurses were invited to participate in the study during the first conference of the European Federation of Critical Care Nursing Associations which was held in Paris in May 2002. A self-administered questionnaire was used to capture the attitudes and experiences of nurses. It consisted of biographical data, 6 questions concerning nurses' experiences of the practice and 30 questions concerning nurses' attitudes of family presence during resuscitation. Generally, critical care nurses supported the presence of family members and the majority (*n* = 94, 76.4%) thought that allowing family members to be present would reassure them to see that everything possible was done to save the patient.

Further, a majority of the nurses (*n* = 71, 57.3%) believed that family might draw comfort from sharing the last moment with patient. Nurses from the UK, however, held significantly more positive attitudes towards the practice than their non-UK counterparts. A more important finding of this study was the strong agreement among nurses that there should be a member of the resuscitation team facilitating family members throughout the experience, including providing emotional support, explanations and interpretations of the procedure, to the attending families. The authors believed that cultural values varying from country to country in Europe may have affected the experiences and attitudes of nurses towards family presence during resuscitation. This study relied on convenience sampling of critical care nurses, so there are difficulties in generalising the results to other areas. Additionally, the questionnaire was based on a review of the existing literature rather than an already validated tool; thus its validity and reliability might be questioned. In spite of the study limitations, the authors propose that further policy be developed accordingly to guide clinical practice.

The concept of family presence during resuscitation has also been researched in the Turkish context [14]. This descriptive study with a quantitative approach sought to explore experiences and opinions of critical care nurses regarding family presence during resuscitation in Turkey. The data were gathered using a 43-item questionnaire [12, 14]. The questionnaire consisted of three main areas: demographic characteristics of nurses, experiences of family presence during resuscitation and nurses' opinions of family presence. The study took place at 10 hospitals, 4 affiliated with the Turkish MOH, 3 affiliated with universities and 3 affiliated with Social Security Agency hospitals. A total of 409 eligible critical care nurses returned the self-report questionnaire [14].

The results indicated that more than half of the nurses had no experience of family presence during resuscitation and none of them had ever invited family members to be present during resuscitation [14]. The study indicated that the majority of the nurses did not agree that it was necessary for family members to be with the patient during resuscitation and they did not want family members to be present. In fact, none of the Turkish hospitals that participated in this study had a protocol or policy allowing family members to be present during resuscitation. The findings reveal that critical care nurses in Turkey are not familiar with the concept of family presence during resuscitation; accordingly, the authors further recommended educational programs about this issue and policy changes within the hospitals to enhance critical care.

Researchers designed and implemented a program of family presence during resuscitation at the Urban Academic Medical Centre [24]. The study assessed the attitudes of all nurses and physicians regarding family presence during resuscitation, using a two group pre-test posttest design. The initial survey was completed by 86 nurses and 35 physicians and the followup survey was completed by 89 nurses and 14 physicians. The questionnaire included three parts, demographic information, professional attitudes and behaviours and personal and professional experience of the practice. Consistent with the study [7–9] found that nurses showed stronger support for the rights of patients to have their families present than did physicians on both surveys. The authors in this study failed to identify the psychological effects of family presence during resuscitation on medical staff; also a limitation that was highlighted by the authors was that anonymity of participants did not allow the authors to evaluate individual change in the practice. Despite the differing concerns of nurses and physicians, the implementation of a family presence program was successful and is now the standard practice at the hospital where the study was conducted.

Associations which was held in Paris in May 2002. A self-administered questionnaire was used to capture the attitudes and experiences of nurses. It consisted of biographical data, 6 questions concerning nurses' experiences of the practice and 30 questions concerning nurses' attitudes of family presence during resuscitation. Generally, critical care nurses supported the presence of family members and the majority (*n* = 94, 76.4%) thought that allowing family members to be present would reassure them to see that everything possible was done to save the patient. Further, a majority of the nurses (*n* = 71, 57.3%) believed that family might draw comfort from sharing the last moment with patient. Nurses from the UK, however, held significantly more positive attitudes towards the practice than their non-UK counterparts. A more important finding of this study was the strong agreement among nurses that there should be a member of the resuscitation team facilitating family members throughout the experience, including providing emotional support, explanations and interpretations of the procedure, to the attending families. The authors believed that cultural values varying from country to country in Europe may have affected the experiences and attitudes of nurses towards family presence during resuscitation. This study relied on convenience sampling of critical care nurses, so there are difficulties in generalising the results to other areas. Additionally, the questionnaire was based on a review of the existing literature rather than an already validated tool; thus its validity and reliability might be questioned. In spite of the study limitations, the authors

propose that further policy be developed accordingly to guide clinical practice.

self-report questionnaire [14].

52 Resuscitation Aspects

The concept of family presence during resuscitation has also been researched in the Turkish context [14]. This descriptive study with a quantitative approach sought to explore experiences and opinions of critical care nurses regarding family presence during resuscitation in Turkey. The data were gathered using a 43-item questionnaire [12, 14]. The questionnaire consisted of three main areas: demographic characteristics of nurses, experiences of family presence during resuscitation and nurses' opinions of family presence. The study took place at 10 hospitals, 4 affiliated with the Turkish MOH, 3 affiliated with universities and 3 affiliated with Social Security Agency hospitals. A total of 409 eligible critical care nurses returned the

The results indicated that more than half of the nurses had no experience of family presence during resuscitation and none of them had ever invited family members to be present during resuscitation [14]. The study indicated that the majority of the nurses did not agree that it was necessary for family members to be with the patient during resuscitation and they did not want family members to be present. In fact, none of the Turkish hospitals that participated in this study had a protocol or policy allowing family members to be present during resuscitation. The findings reveal that critical care nurses in Turkey are not familiar with the concept of family presence during resuscitation; accordingly, the authors further recommended educational programs about this issue and policy changes within the hospitals to enhance critical care.

Researchers designed and implemented a program of family presence during resuscitation at the Urban Academic Medical Centre [24]. The study assessed the attitudes of all nurses and physicians regarding family presence during resuscitation, using a two group pre-test posttest design. The initial survey was completed by 86 nurses and 35 physicians and the followup survey was completed by 89 nurses and 14 physicians. The questionnaire included three At the same time that the study [24] was released, another study in different contexts has been published on family presence during resuscitation. It examined the perception of 90 emergency nurses towards the family presence during resuscitation at Cork University Hospital in Ireland [25]. The authors in this study used a descriptive quantitative design through a questionnaire utilised for the study, which was developed by the ENA. The sample was a convenience sample of 90 nurses working in a level 1 trauma ED with over 6 months' experience. The nurses were predominantly females (83.3%) in the 30–40 years age group and were employed as staff nurses (80%). Surprisingly, the study showed that 58.9% of the participants had invited family members to attend the resuscitation. Another 17.8% had not had the opportunity to do so, but would allow the family members to be present if the opportunity arose. However, 74.4% of the nurses preferred a written policy, which gives the family members the option of being present during resuscitation. In spite of using a quantitative design which did not allow the nurses' perceptions to be explored in detail, the study has clinical implications. The study emphasised the need to develop educational programs for nurses on the safe implementation and practices of families witnessing resuscitations.

A descriptive study using survey methods was conducted to investigate the outcomes of family presence on staff attitude immediately post-resuscitation [26]. The findings here are part of a larger project of family presence that was conducted at a tertiary referral hospital in Brisbane in Queensland, Australia. The participants of this study were any medical staff members present during resuscitation of patients who met the inclusion criteria for the study. The inclusion criteria for an eligible resuscitation were Australian patients presenting as Triage Categories 1 or 2, with or without an altered level of consciousness, hypotension, respiratory distress or the need for CPR. The majority of the informants were nurses, followed by registrars, residents, consultants then social workers. In this survey, the staff felt there were positive aspects and advantages for relatives being present during resuscitation. These advantages include being able to obtain a medical history quickly; the patients being comforted by having relatives present; and the relatives benefiting by being present; thus the staff thought it was easier to manage while the relatives were present.

This study provided an Australian and international perspective to the existing research literature on staff attitudes to family members present during resuscitation, and a new perspective as well by examining staff attitudes immediately post-resuscitation. The findings of this study further support the presence during resuscitation within an environment that supports staff to undertake the care of the patients with their family being present.

Nurses' opinions of family presence during resuscitation have been influenced by culture and religion, according to Cunes [27]. This study [12, 14] replicated survey to determine the experiences and attitudes of Turkish intensive care nurses concerning family presence during resuscitation. Using a descriptive design research study, they surveyed 135 intensive care nurses from 2 university hospitals in Izmir by structured questionnaires [12, 27]. The vast majority (88.1%) disagreed that family members should be given the option to remain with their loved one during resuscitation. Only 22.2% of the intensive care nurses participated in resuscitation where family members were present. Almost all nurses (91.1%) agreed that they did not want family members to be present.

In addition, all nurses indicated that they had no protocol on family presence during resuscitation. Nurses agreed (72.6%) that family members, if present, would interfere with the resuscitation team performance and 86.6% of nurses believed that witnessing resuscitation by family members is a traumatic experience and a very stressful situation. The findings of this study are consistent with those of Ref. [14] as to the lack of support of Turkish intensive care nurses, which is a result of nurses having no knowledge, and neither policy nor protocol for family presence during resuscitation. The researchers concluded that educational programs, if implemented together with the developmental of protocols and guidelines, should both aid in the acceptance of the concept by the intensive care nurses in Turkey. The instrument used did not have any open-ended questions to allow nurses to write their additional thoughts.

Authors from Germany conducted another descriptive survey study to explore the German intensive care nurses' experiences and attitudes towards family presence during resuscitation [28]. The study used the questionnaire which was developed by Fulbrook et al. [12]; however, a fourth section was added to allow delegates to further write any additional concerns related to the issue. Unlike Ref. [12], this qualitative data enhanced both the depth and comprehensiveness of the participants' experiences. A total of 164 intensive care nurses were recruited who attended the 26th Reutlinger Fortbildungstage held in Reutlingen, Baden-Wurttemberg, Germany during September 2008. According to the researchers, most of the participants (68%) did not agree that family members should be given the option of being present during the resuscitation of their loved one. Also, over half (56%) were concerned that family presence would disturb the performance of the resuscitation team.

Consistent with Ref. [12] informants in this study, 73.5% agreed that there should be a dedicated member of the resuscitation team who should be available to meet the family needs, for instance to support and explain the resuscitation procedure to the family members. Moreover, 68% of nurses believed that family presence could help them to know that everything possible was done for their patient, which was also found [12]. Nurses in this study indicated that they rarely invited family to be present, which might be due to the lack of unit protocol or practice guideline. Researchers interpreted that the nurses' decision regarding practice might have been influenced by the German cultural values and societal traditions. The study encouraged simulation training techniques to assist practitioners to increase their confidence, overcome their fears and support the family during the situation: those topics are to be introduced within the nursing curricula.

In Iran, a study was undertaken to determine the opinions of health care providers of family presence during resuscitation and other invasive procedures in four teaching hospitals in Tehran [29]. A total of 200 health care providers were surveyed by a questionnaire developed for the study which asked about the demographic characteristics of the respondents, years of working experience and opinions about relatives' presence during intubation and resuscitation. The participants' age, gender, experience and speciality did not correlate with the participants' attitudes towards family presence. However, participants with previous exposure to family presence were more in favour of family presence. Similar to a study previously sampled from nurses in another Muslim community in Turkey [14], the results of this study revealed that the majority (77.9%) opposed the practice. The most common reasons for the participants' opposition, as indicated by the authors, were the health care providers' fear of psychological trauma to family members, possible interference with patient care as the Muslim families are potentially closer and more prone to display emotions which may distract the resuscitation team.

Further, a total of 132 nurses were surveyed nurses using a self-administered questionnaire in two hospitals in Saudi Arabia [30]. The study found that 75.6% of the participants did not support the family presence practice indicating the same reasons as Ref. [29] for opposition such as witnessing resuscitation is a traumatic experience and fearing that family members will negatively impact on the resuscitation team. An interesting finding was a statistically significant relationship between nurses with previous experience of family presence and support for the practice [30]. Nurses with previous experience of family presence opposed the practice more than nurses with no previous experience (*P* = 0.001). However, this was not the case where ICU health care providers with previous experience of family presence during resuscitation were found to be more supportive of the practice, compared to the health care providers with no previous experience [28]. Authors maintained that the Islamic religion and the Saudi culture influenced the nurses' attitudes towards the practice of family presence [30].

Significantly, different perceptions can be perceived regarding family presence during resuscitation [31]. However, studies have shown that family members consider the need to be close to the patient as very important as the unpredicted admission without any warning causes high level of stress and anxiety among family members [31]. Additionally, the experience resuscitation creates an intense emotional situation for both patients and their family members [32]. The health care providers reported a need for training programmes to support the family when they attend resuscitation [30–32]. A number of studies also emphasised the need to develop educational programmes for medical staff on the safe implementation and practice of family presence [12, 24, 28]. The health care providers also indicated the need to develop policies to support family involvement and give family the option to attend resuscitation [31].

### **6. Conclusion**

Nurses' opinions of family presence during resuscitation have been influenced by culture and religion, according to Cunes [27]. This study [12, 14] replicated survey to determine the experiences and attitudes of Turkish intensive care nurses concerning family presence during resuscitation. Using a descriptive design research study, they surveyed 135 intensive care nurses from 2 university hospitals in Izmir by structured questionnaires [12, 27]. The vast majority (88.1%) disagreed that family members should be given the option to remain with their loved one during resuscitation. Only 22.2% of the intensive care nurses participated in resuscitation where family members were present. Almost all nurses (91.1%) agreed that they

In addition, all nurses indicated that they had no protocol on family presence during resuscitation. Nurses agreed (72.6%) that family members, if present, would interfere with the resuscitation team performance and 86.6% of nurses believed that witnessing resuscitation by family members is a traumatic experience and a very stressful situation. The findings of this study are consistent with those of Ref. [14] as to the lack of support of Turkish intensive care nurses, which is a result of nurses having no knowledge, and neither policy nor protocol for family presence during resuscitation. The researchers concluded that educational programs, if implemented together with the developmental of protocols and guidelines, should both aid in the acceptance of the concept by the intensive care nurses in Turkey. The instrument used did not have any open-ended questions to allow nurses to write their additional thoughts.

Authors from Germany conducted another descriptive survey study to explore the German intensive care nurses' experiences and attitudes towards family presence during resuscitation [28]. The study used the questionnaire which was developed by Fulbrook et al. [12]; however, a fourth section was added to allow delegates to further write any additional concerns related to the issue. Unlike Ref. [12], this qualitative data enhanced both the depth and comprehensiveness of the participants' experiences. A total of 164 intensive care nurses were recruited who attended the 26th Reutlinger Fortbildungstage held in Reutlingen, Baden-Wurttemberg, Germany during September 2008. According to the researchers, most of the participants (68%) did not agree that family members should be given the option of being present during the resuscitation of their loved one. Also, over half (56%) were concerned that family presence

Consistent with Ref. [12] informants in this study, 73.5% agreed that there should be a dedicated member of the resuscitation team who should be available to meet the family needs, for instance to support and explain the resuscitation procedure to the family members. Moreover, 68% of nurses believed that family presence could help them to know that everything possible was done for their patient, which was also found [12]. Nurses in this study indicated that they rarely invited family to be present, which might be due to the lack of unit protocol or practice guideline. Researchers interpreted that the nurses' decision regarding practice might have been influenced by the German cultural values and societal traditions. The study encouraged simulation training techniques to assist practitioners to increase their confidence, overcome their fears and support the family during the situation: those topics are to be introduced

In Iran, a study was undertaken to determine the opinions of health care providers of family presence during resuscitation and other invasive procedures in four teaching hospitals in

did not want family members to be present.

54 Resuscitation Aspects

would disturb the performance of the resuscitation team.

within the nursing curricula.

In general, most of the reviewed studies were descriptive, using either quantitative or qualitative approaches. The family members in those earlier reviewed studies indicated their desire and supported their presence during resuscitation. They also advocated further benefits including helping the patient, knowing everything possible was done to save their loved one and support provided to grieving family members. These findings highlight the importance of giving the health care providers the confidence in including the family during the care of the patient and considering them as part of the caring team. The studies also demonstrated that health care providers have significantly different opinions regarding family presence during resuscitation. Some oppose family presence for many reasons including that the practice would be offensive, produces stress in staff and that family members may interfere with the treatment. Other health care providers were comfortable with the family presence and believed that it would positively affect patient care, agreeing that their presence would reassure them that the best care is being provided. It was obvious that the research so far has failed to identify the psychological effects of family presence on the families during resuscitation. Regardless of the difference in health care providers' views, some endorsed the need for written policies to allow family presence and others suggested a 'nurse facilitator' dedicated to evaluate readiness of the family members to attend the procedure and explain it to them when they attend.

The findings of this research suggest a number of recommendations, including clinical implications and further research which include the following:

### **6.1. Clinical implication**

The decision to implement the family presence practice should be well prepared. The decision needs to be made at the individual level (health care providers) and organisational level (hospitals). The study helped also to identify some issues which needed to be addressed before offering the option to families to be present during the resuscitation attempts on their family member. The identified issues include guidelines, written policies, informed consent and family presence educational programs.

A significant concern should be given to the family presence policy. The policy must ensure providing the family members a safe and caring environment. Before the option is offered, the families should be assessed for coping abilities and the absence of extreme psychological and emotional disturbance. The policy also should stress on the nurse facilitator interventions regarding the follow-up and explanations to the family throughout the procedure. Therefore, this study suggested a proposed practice standard (Appendix A) that could help to fulfil the family as a whole, rather than treating the patient individually and assures the safe implementation of family presence during the resuscitation of the loved one.

Secondly, the family presence educational programs should benefit the health care providers and families who would like to attend the resuscitation of their loved one. Accordingly, staff support programs should be developed to assist families who want to be present during resuscitation. Health care facilities also should contribute educational sessions on the family presence practice for the society to be well informed and have adequate knowledge of the practice. Through different teaching strategies, the family presence practice can be instructed to the participants such as lectures or pamphlets. This study suggested a proposed assessment of the family members to cope with the situation, and the infection control practices for safe implementation by the health care providers.

### **6.2. Further research**

and support provided to grieving family members. These findings highlight the importance of giving the health care providers the confidence in including the family during the care of the patient and considering them as part of the caring team. The studies also demonstrated that health care providers have significantly different opinions regarding family presence during resuscitation. Some oppose family presence for many reasons including that the practice would be offensive, produces stress in staff and that family members may interfere with the treatment. Other health care providers were comfortable with the family presence and believed that it would positively affect patient care, agreeing that their presence would reassure them that the best care is being provided. It was obvious that the research so far has failed to identify the psychological effects of family presence on the families during resuscitation. Regardless of the difference in health care providers' views, some endorsed the need for written policies to allow family presence and others suggested a 'nurse facilitator' dedicated to evaluate readiness of the family members to attend the procedure and explain it to them

The findings of this research suggest a number of recommendations, including clinical impli-

The decision to implement the family presence practice should be well prepared. The decision needs to be made at the individual level (health care providers) and organisational level (hospitals). The study helped also to identify some issues which needed to be addressed before offering the option to families to be present during the resuscitation attempts on their family member. The identified issues include guidelines, written policies, informed consent and fam-

A significant concern should be given to the family presence policy. The policy must ensure providing the family members a safe and caring environment. Before the option is offered, the families should be assessed for coping abilities and the absence of extreme psychological and emotional disturbance. The policy also should stress on the nurse facilitator interventions regarding the follow-up and explanations to the family throughout the procedure. Therefore, this study suggested a proposed practice standard (Appendix A) that could help to fulfil the family as a whole, rather than treating the patient individually and assures the safe implementation of family presence during the resuscitation of the

Secondly, the family presence educational programs should benefit the health care providers and families who would like to attend the resuscitation of their loved one. Accordingly, staff support programs should be developed to assist families who want to be present during resuscitation. Health care facilities also should contribute educational sessions on the family presence practice for the society to be well informed and have adequate knowledge of the practice. Through different teaching strategies, the family presence practice can be instructed to the participants such as lectures or pamphlets. This study suggested a proposed assessment of the family members to cope with the situation, and the infection control practices for

cations and further research which include the following:

when they attend.

56 Resuscitation Aspects

loved one.

**6.1. Clinical implication**

ily presence educational programs.

safe implementation by the health care providers.

Future studies should include other health care providers' attitudes regarding family presence practice. It is most important to study the view of patients and family members as to whether they really want to and benefit from being the family presence during resuscitation for both adults and paediatric patients. This study also will act as a stimulus for further research in an area of family presence during resuscitation.

### **6.3. Recommendations for successful family presence program**

	- Assessment of family members' ability to cope with the situation and the absence of extreme emotional disturbance behaviours.
	- Removal of the non-essential equipment from the resuscitation room in order to make space for the family members.
	- Infection control practices, for example, the family members may be asked to wear gloves, gown or eye protection to prevent exposure to blood or body fluids.

### **7. Standard of practice for family presence during resuscitation**

### **7.1. Definition**

It is the presence of family members during the resuscitation of their loved one.

### **7.2. Purpose**

To treat the patients and families holistically and to support the family needs.

#### **7.3. Policy statement**

Family members will be permitted in the patient care during resuscitation of their family member.

### **7.4. Procedure**

**1.** The nurses will be responsible for assessing patient and family needs to be present during resuscitation.


The nurse facilitator will:


### **Author details**

Abbas Al Mutair

Address all correspondence to: abbas4080@hotmail.com

Inaya Medical College, Riyadh, Saudi Arabia

### **References**


[5] Moreland P, Manor B. Family presence during invasive procedures and resuscitation in the emergency department: A review of the literature. Journal of Emergency Nursing. 2005;**31**(1):58-72

**2.** The facilitator nurse is responsible for assessing the family members' ability to cope with the situation and the absence of extreme emotional disturbance behaviours before the op-

**3.** If the facilitator nurse agrees to allow the family members during the resuscitation, the

**4.** Only two of family members will be allowed in the resuscitation room, prioritising the

**5.** Prior to entering the resuscitation room, the facilitator will explain to the relatives about the patient's condition, treatments and equipment available in the room, where they stand

• Provide information about the expected outcomes and the patient's response to the

• Reassure the relatives, open space for the family's point of view and answer their questions.

[1] Doyle CJ, Post H, Burney RE, Maino J, Keefe M, Rhee KJ. Family participation during

[2] Hanson C, Strawser D. Family presence during cardiopulmonary resuscitation: Foote Hospital emergency department's nine-year perspective. Journal of Emergency Nursing.

[3] Emergency Nurses Association. Family presence at the bedside during invasive procedures and cardiopulmonary resuscitation. Emergency Nurses Association White Paper.

[4] Meyers TA, Eichborn DJ, Guzzetta CE, Clark AP, Taliaferro E. Family presence during invasive procedures and resuscitation: The experience of family members, nurses, and

physicians. Topics in Emergency Medicine. 2004;**26**(1):61-73

resuscitation: An option. Annuls of Emergency Medicine. 1987;**16**:673-675

patient (if conscious) will be asked if they agree for the family to be present.

in the room and when they may leave if any psychological distress appears.

**6.** The family members will be accompanied by the facilitator in the resuscitation room.

next of kin and at this time the consent must be secured by the family members.

tion can be offered.

58 Resuscitation Aspects

The nurse facilitator will:

treatment.

**Author details**

Abbas Al Mutair

**References**

1992;**18**:104-106

2005:1-6

• Explain the procedure to the family members.

Address all correspondence to: abbas4080@hotmail.com

Inaya Medical College, Riyadh, Saudi Arabia


**Extending Guidelines and Research**

[20] Helmer D, Shapiro M, Dors M, Karan S. Family presence during trauma resuscitation: A survey of American Association of Sleep Technologists and Emergency Nurses Association members. Journal of Trauma Injury Infection Critical Care. 2000;**48**:1015-1020

[21] Boyd R, White S. Does witnessed cardiopulmonary resuscitation alter perceived stress in accident and emergency staff? European Journal of Emergency Medicine. 2000;**7**:51-53

[22] Ellison S. Nurses' attitudes toward family presence during resuscitative efforts and inva-

[23] Knott A, Kee C. Nurses' beliefs about family presence during resuscitation. Applied

[24] Mian P, Warchal S, Whitney S, Fitzmaurice J, Tancredi K. Impact of a multifaceted intervention on nurses' and physicians' attitudes and behaviours toward family presence

[25] Madden E, Condon C. Emergency nurses current practices and understanding of family

[26] Holzhauser K, Finucane J. Part B: A survey of the staff attitudes immediately postresuscitation to family presence during resuscitation. Australasian Emergency Nursing

[27] Cunes U, Zaybak A. A study of Turkish critical care nurses' perspectives regarding family-witnessed resuscitation. Journal of Clinical Nursing. 2009;**18**:2907-2915

[28] Koberich S, Kaltwasser A, Rothaug O, Albarran J. Family witnessed resuscitation— Experience and attitudes of German intensive care nurses. British Association of Critical

[29] Kianmeher N, Mofidi M, Rahmani H, Shahin Y. The attitudes of team members towards family presence during hospital-based CPR: A study based in the Muslim setting of four Iranian teaching hospitals. Journal of Royal College and Physicians of Edinburgh.

[30] Al-Mutair A, Plummer V, Copnell B. Family presence during resuscitation: A descriptive study of nurses' attitudes from two Saudi hospitals. Nursing in Critical Care.

[31] Al-Mutair AS, Plummer V, O'brien A, Clerehan R. Family needs and involvement in the intensive care unit: A literature review. Journal of Clinical Nursing. 2013;**22**(13-14):

[32] Mohamed Z, Sasikala M, Nurfarieza MA, Ho SE. Needs of family members of critically ill patients in a Critical Care Unit at Universiti Kebangsaan Malaysia Medical Centre.

presence during CPR. Journal of Emergency Nursing.2007;**33**(5):433-440

sive procedures, Journal of Emergency Nursing. 2003;**29**(6):515-521

during resuscitation. Critical Care Nurse. 2007;**27**(1):52-61

Nursing Research. 2005;**18**;192-198

60 Resuscitation Aspects

Journal. 2008;**11**:114-122

2010;**40**:4-8

1805-1817

2012;**17**(2):90-98

Care Nurses. 2010;**5**(15):241-250

Medicine & Health. 2016; **11**(1):11-21

#### **Chest Compression-Only Cardiopulmonary Resuscitation** Chest Compression-Only Cardiopulmonary Resuscitation

DOI: 10.5772/intechopen.70830

#### Hui-Chun Chen and Shoa-Lin Lin Hui-Chun Chen and Shoa-Lin Lin

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.70830

### Abstract

The survival rate of out-of-cardiac arrest (OHCA) was very low, which was mainly due to the victims who do not receive cardiopulmonary resuscitation (CPR) immediately. It was estimated that if people who quickly get chest compression-only CPR while awaiting medical treatment have double or even triple the chance of surviving. In the true world, many individuals are unwilling to do mouth-to-mouth breathing due to fear of infections or unable to do mouth-to-mouth breathing at the same time in the situation of only one bystander. This article has performed an extensive review in order to update the concept of chest compression-only CPR.

Keywords: cardiac arrest, cardiopulmonary resuscitation (CPR), chest compression, out-of-hospital cardiac arrest (OHCA), return of spontaneous circulation (ROSC)

### 1. Introduction

More than 300,000 Americans died from cardiac arrest each year [1]. Cardiopulmonary resuscitation (CPR) provided by a bystander may improve outcome [2] but is generally performed in less than 30% of the cases [3, 4].

Survival rate of out-of-cardiac arrest (OHCA) is only about 7% [5] in previous 2 decades. According to etiology, cardiac arrest can be divided into asphyxial and non-asphyxial types. Asphyxial arrest is caused by situations inducing low blood oxygen status, like drawing, suicide on the hanging, monoxide carbon intoxication, etc. The non-asphyxial arrest is due to dysfunction of cardiac electrical activity [6]. This article will focus in non-asphyxial OHCA patients. The major reason of low survival rate of OHCA patients is that they do not receive CPR immediately. The 2010 American Heart Association (AHA) guidelines made a change of the sequence of CPR from A, airway; B, breathing; C, chest compression (A-B-C) to C-A-B to put an emphasis on chest compression and its rate and depth. This change could make CPR more easy to start and minimize delaying time for ventilation. Starting CPR from mouth-to-mouth

distribution, and eproduction in any medium, provided the original work is properly cited.

ventilation is a big barrier in real world due to fear of communicating infectious disease or other reasons. Except that it is easier to start CPR from chest compressions, this change from A-B-C to C-A-B make the cardiac arrest patient earlier to receive chest compression which is the most important element of CPR. The delay time for ventilation would also be shorter than before, like receiving ventilation after 30 chest compressions or is about only 18 seconds of delay at the speed of at least 100 chest compression/minute or even shorter if there two bystanders who resuscitated children or infant. Chest compression-only CPR is encouraged in certain condition like only one rescuer, untrained rescuers, or multiple rescuers who are unwilling to do mouthto-mouth ventilation [7]. There are randomized trials that support results of chest compressiononly CPR recently [8, 9]. Chest compression-only CPR is easier to do by untrained bystander and is easier to be introduced by dispatcher by phone and increase actual provision by bystanders [10].

In this work, we will firstly describe our recent successful experience treating a case with OHCA after chest compression-only CPR who has complete neurological recovery [11] and perform an extensive review in order to update the concept of chest compression-only CPR.

### 2. Case presentation

A 55-year-old male had smoking history for 40 years but without prior history of diabetes mellitus, hypertension, or hyperlipidemia. He developed collapse suddenly in the presence of his exercise partners when playing tennis. One exercise partner called for emergency medical service (EMS) team, and another partner began chest compression-only CPR immediately. The compression-only CPR was performed by one bystander for the initial 8 minutes, followed by two persons alternatively. After 28 minutes, the paramedic team arrived. At that time, the patient was unresponsive, no detectable blood pressure, pulseless, and without spontaneous respiration. The EMS team secured the airway and performed ventilation via Ambu bagging and continuous chest compression. After 10 minutes of CPR, the EMS found a detectable carotid pulse, the ECG monitor showed sinus rhythm but with wide QRS complex. For the prehospital resuscitation, the return of spontaneous circulation (ROSC) was achieved after 28 minutes of chest compression-only CPR by bystanders plus 10 minutes of assisted ventilation/chest compression by EMS. The patient had a blood pressure of 180/105 mmHg, heart rate of 88/minute, respiratory rate of 12/minute, and SpO2 of 99%. Nevertheless, he was still unresponsive with Glasgow Coma Scale of E1V1M1. The patient was then transported to our emergency department where he received endotracheal intubation immediately. The vital signs revealed body temperature, 36.1C; pulse rate, 125 bpm; respiratory rate, 20/minute; blood pressure, and 122/96 mmHg, but the coma scale was E1V1M1. He was transferred to the intensive care unit promptly. His conscious level mildly improved from E1V1M1 to E2VTM3 after admitted at the intensive care unit. On the third admission day, his consciousness recovered (from E2VTM3 to E4V5M6), and he was extubated. He was transferred to the general ward on the fourth hospital day. On the fifth hospital day, the percutaneous coronary intervention and electrophysiological study were suggested, but patient refused due to a personal reason. A computed tomographic coronary angiogram studied on the sixth hospital day showed significant stenosis of the right coronary artery and heavy calcifications of both left anterior and left circumflex coronary arteries. On the seventh hospital day, he was discharged without any neurological or memory impairment. Thus, this case supports the present CPR guideline that recommends effective chest compression without assisted ventilation by laypersons for managing patients in cardiac arrest.

### 3. Searching strategy

ventilation is a big barrier in real world due to fear of communicating infectious disease or other reasons. Except that it is easier to start CPR from chest compressions, this change from A-B-C to C-A-B make the cardiac arrest patient earlier to receive chest compression which is the most important element of CPR. The delay time for ventilation would also be shorter than before, like receiving ventilation after 30 chest compressions or is about only 18 seconds of delay at the speed of at least 100 chest compression/minute or even shorter if there two bystanders who resuscitated children or infant. Chest compression-only CPR is encouraged in certain condition like only one rescuer, untrained rescuers, or multiple rescuers who are unwilling to do mouthto-mouth ventilation [7]. There are randomized trials that support results of chest compressiononly CPR recently [8, 9]. Chest compression-only CPR is easier to do by untrained bystander and is easier to be introduced by dispatcher by phone and increase actual provision by

In this work, we will firstly describe our recent successful experience treating a case with OHCA after chest compression-only CPR who has complete neurological recovery [11] and perform an extensive review in order to update the concept of chest compression-only CPR.

A 55-year-old male had smoking history for 40 years but without prior history of diabetes mellitus, hypertension, or hyperlipidemia. He developed collapse suddenly in the presence of his exercise partners when playing tennis. One exercise partner called for emergency medical service (EMS) team, and another partner began chest compression-only CPR immediately. The compression-only CPR was performed by one bystander for the initial 8 minutes, followed by two persons alternatively. After 28 minutes, the paramedic team arrived. At that time, the patient was unresponsive, no detectable blood pressure, pulseless, and without spontaneous respiration. The EMS team secured the airway and performed ventilation via Ambu bagging and continuous chest compression. After 10 minutes of CPR, the EMS found a detectable carotid pulse, the ECG monitor showed sinus rhythm but with wide QRS complex. For the prehospital resuscitation, the return of spontaneous circulation (ROSC) was achieved after 28 minutes of chest compression-only CPR by bystanders plus 10 minutes of assisted ventilation/chest compression by EMS. The patient had a blood pressure of 180/105 mmHg, heart rate of 88/minute, respiratory rate of 12/minute, and SpO2 of 99%. Nevertheless, he was still unresponsive with Glasgow Coma Scale of E1V1M1. The patient was then transported to our emergency department where he received endotracheal intubation immediately. The vital signs revealed body temperature, 36.1C; pulse rate, 125 bpm; respiratory rate, 20/minute; blood pressure, and 122/96 mmHg, but the coma scale was E1V1M1. He was transferred to the intensive care unit promptly. His conscious level mildly improved from E1V1M1 to E2VTM3 after admitted at the intensive care unit. On the third admission day, his consciousness recovered (from E2VTM3 to E4V5M6), and he was extubated. He was transferred to the general ward on the fourth hospital day. On the fifth hospital day, the percutaneous coronary intervention and electrophysiological study were suggested, but patient refused due to a personal reason. A computed tomographic coronary angiogram studied on the sixth hospital

bystanders [10].

64 Resuscitation Aspects

2. Case presentation

We use a medical term as "chest compassion-only CPR" and search relevant papers from the PubMed, Medline + Journals@ Ovid, and Cochrane library. There were no restrictions for sex or populations. We do not restrict search criteria to humans or animals. We only limit search criteria to English language, review articles, and publication year from January 2010 to August 2017. We limit that the publication year is hoping to get the most updated information. We found that there were 35 review articles from PubMed, 11 review articles in Medline + Journals@ Ovid, and 1 review article in Cochrane, respectively. The repeated data were found in 10 articles; thus, only 37 articles were obtained in the systemic review. We will report the updated information relevant to the chest compression-only CPR. Other issues including mechanical chest compression devices, pharmacological agents in cardiac arrest, and postresuscitation care are not included in this article.

### 4. Increasing rates of bystander CPR

Successful treatment of OHCA patients remains an unmet health demand. The crucial components of treatment consist of early recognition of cardiac arrest, prompt and effective CPR, effective and early defibrillation, and organized post-resuscitation care. The initiation of bystander CPR followed by a prompt emergency response delivers high-quality CPR, which is critical to patients' outcomes. Before 2010, most OHCA patients do not receive any bystander CPR even if there is a bystander at the scene [12]. One of the probable reasons is due to the A-B-C sequence of CPR, which makes rescuers feel difficult to start CPR from opening the airway and delivering breaths with mouth-to-mouth ventilation. The bystanders would rather call emergent medical service (EMS) team and await emergency staff to arrive to start CPR. Thus, such cardiac arrest patient's outcome is very poor. Bystanders do not start CPR because they are afraid of get hurt, contacting infectious disease, not enough confidence to practice complicated conventional CPR, and following legal problems [13]. Changing CPR sequence as C-A-B in 2010 AHA guideline might encourage rescuers more easily to begin CPR from starting with chest compressions compared with staring from mouth-to-mouth ventilation. Besides, this change can let OHCA patients receive chest compression earlier without delay due to giving ventilation. Giving ventilation first not only delays chest compression but also increases thoracic pressure, decreases venous return, and decreases coronary artery pressure. This vicious cycle brings poor prognosis of cardiac arrest victim. A recent report found that the chance of selecting compression-only CPR markedly increased from 36.4% in 2005– 2007 to 63.7% in 2011–2012 [14]. This change in results may be explained by the increase of dispatcher instruction to lay rescuers, concept change after the 2010 AHA guideline, and most importantly the dissemination of compression-only CPR in the CPR training program [15, 16]. Thus, a few recommendations may be helpful to increase rate of bystander CPR including to broaden CPR training, provide reassurance to increase participation, improve EMS quality which are discussed in this section.

### 4.1. Broaden CPR training

In order to spread and accelerate CPR education, new approaches are required to reach a larger public audience. Lynch et al. have develop and validate a 30-minute CPR selfinstruction program for laypersons [17]. This CPR course has provided a useful tool for education outside the classroom. Another way to broaden CPR training might be through recently developed automated external defibrillator (AED) programs. The Cardiac Arrest Survival Act (CASA; Public Law 106–505) mandated establishment of lay rescuer AED programs in federal buildings. Many state governments have carried out AED programs in public places, like airport, hotels, gymnasiums, schools, nursing homes, and train stations. CPR trainings held by governments are inspired to provide CPR training for future rescuers as part of the comprehensive community lay rescuer AED plans. The AHA has provided information to schools to help them prepare to respond to medical emergencies, including sudden cardiac death [18].

### 4.2. Dispatcher-assisted "telephone CPR"

The broadened CPR training is helpful to the public laypersons. However, these CPR trainings may not resolve the problem for the cardiac arrest victims that occur at home, where only a few untrained witnesses may commonly be present. The development of dispatcher-assisted "telephone CPR" may allow for CPR instruction in real time even when rescuers have not received prior training. Dispatcher-assisted "telephone CPR" is especially important for cardiac arrest at home where without trained rescuers or available AEDs. Dispatcher-assisted CPR instruction variations have been surveyed [19, 20] and have found that this "training" method was a useful technique to lay rescuers for direct CPR care.

### 4.3. Offer reassurance to increase participation

Bystander reluctance to perform CPR is common. The government officers must announce that the chance of disease transmission is very low. To the best of our knowledge, there was no case report of human immunodeficiency virus or hepatitis transmission through performance of CPR up-to-date. In combination with Occupational Safety and Health Administration recommendations for places of working, decision-makers should provide devices of mouth-to-mouth barrier and gloves where AEDs are available. Those devices can assist CPR performance when AEDs are used. CPR classes should be included in Good Samaritan legislation [21] and published near AED installations. The public should realize that the survival chance of OHCA victim can be double or triple if bystanders practicing CPR immediately, while the CPR performance is at little risk to the rescuer.

### 4.4. Strengthen CPR practice and EMS quality

dispatcher instruction to lay rescuers, concept change after the 2010 AHA guideline, and most importantly the dissemination of compression-only CPR in the CPR training program [15, 16]. Thus, a few recommendations may be helpful to increase rate of bystander CPR including to broaden CPR training, provide reassurance to increase participation, improve EMS quality

In order to spread and accelerate CPR education, new approaches are required to reach a larger public audience. Lynch et al. have develop and validate a 30-minute CPR selfinstruction program for laypersons [17]. This CPR course has provided a useful tool for education outside the classroom. Another way to broaden CPR training might be through recently developed automated external defibrillator (AED) programs. The Cardiac Arrest Survival Act (CASA; Public Law 106–505) mandated establishment of lay rescuer AED programs in federal buildings. Many state governments have carried out AED programs in public places, like airport, hotels, gymnasiums, schools, nursing homes, and train stations. CPR trainings held by governments are inspired to provide CPR training for future rescuers as part of the comprehensive community lay rescuer AED plans. The AHA has provided information to schools to help them prepare to respond to medical emergencies, including sudden cardiac

The broadened CPR training is helpful to the public laypersons. However, these CPR trainings may not resolve the problem for the cardiac arrest victims that occur at home, where only a few untrained witnesses may commonly be present. The development of dispatcher-assisted "telephone CPR" may allow for CPR instruction in real time even when rescuers have not received prior training. Dispatcher-assisted "telephone CPR" is especially important for cardiac arrest at home where without trained rescuers or available AEDs. Dispatcher-assisted CPR instruction variations have been surveyed [19, 20] and have found that this "training"

Bystander reluctance to perform CPR is common. The government officers must announce that the chance of disease transmission is very low. To the best of our knowledge, there was no case report of human immunodeficiency virus or hepatitis transmission through performance of CPR up-to-date. In combination with Occupational Safety and Health Administration recommendations for places of working, decision-makers should provide devices of mouth-to-mouth barrier and gloves where AEDs are available. Those devices can assist CPR performance when AEDs are used. CPR classes should be included in Good Samaritan legislation [21] and published near AED installations. The public should realize that the survival chance of OHCA victim can be double or triple if bystanders practicing CPR immediately, while the CPR

which are discussed in this section.

4.2. Dispatcher-assisted "telephone CPR"

4.3. Offer reassurance to increase participation

performance is at little risk to the rescuer.

method was a useful technique to lay rescuers for direct CPR care.

4.1. Broaden CPR training

66 Resuscitation Aspects

death [18].

Lay rescuers and EMS training projects of the community must include a course of continuous quality improvement that includes reviewing of resuscitation attempts, CPR quality, and dispatcher CPR instructions that will be offered to bystanders. Healthcare provider systems must perform continuous quality improvement plans that include monitoring the quality of CPR practiced during any resuscitation efforts. These monitored data must be used to maximize resuscitation care quality, including CPR practice quality. Nowadays, several devices have been made to both estimate and offer feedback about CPR practice, either extra capabilities of CPR monitor of defibrillators or stand-alone equipment which rescuers can use before a defibrillator available at the scene of cardiac arrest [22, 23]. Some of these devices, like "pistontype mechanical cardiopulmonary resuscitation device," can also record CPR performance and provide opportunities for training [24]. These tools may have an important impact on this quality improvement goal.

### 5. Quality of chest compression element of CPR

Chest compression is the most important element of CPR. Excellent chest compression can maximize coronary perfusion pressure and increase the chance of ROSC. Chest compression helps blood from the heart to arterial system and coronary artery system. At the release phase of chest compression, the blood returns to the heart under negative thoracic pressure, so that external chest compression helps the "heart works again" and provides about 30% blood supply as normal heart works [25, 26].

New data continuously come out which validate the importance of both the practicing CPR per set and assuring CPR quality are most favorable. The International Liaison Committee for Resuscitation performed a systematic review of evidence for the optimal chest compression characteristics during the 2010 Consensus on Science and Treatment Recommendations Conference. The final conclusions of this review were recommendations for deeper (≧5 cm) and quicker (≧100/minute) chest compressions, ensuring full release of pressure between compression and minimizing interruptions in chest compressions [27]. Here we will discuss in-depth of each element of CPR.

### 5.1. Chest compression rate and depth

External chest compression rate is suggested at least 100/minute in 2010 AHA guideline. Chest compression number is an important determination of survival with good neurological function and ROSC which is the most powerful predictor of survival from OHCA [3]. The OHCA patient who receives chest compression rate between 100 and 120/minute has a greatest chance to survival to discharge according to 2010 AHA guideline [28].

Except chest compression rate, chest compression depth is suggested to at least 2 in (5 cm) in 2010 AHA guideline but not 1½–2 in (4–5 cm) before. Chest compression depth directly compresses the heart and increases to create intrathoracic pressure to generate blood flow, which bring oxygen to the brain and heart. Deeper chest compression is associated with higher chance of survival to hospital. Every 0.5 cm increase depth doubles the chance of successful resuscitation [29]. Enough depth of chest compression is also a key to survival. However, chest compression depth has a reverse relation to chest compression rate. The higher chest compression rate and the lower chest compression depth have been noted. If chest compression rate up to 145/minute is done, the depth of chest compression becomes unacceptable according to 2005 AHA guideline [30].

The 2010 AHA guideline suggests chest compression depth of at least 2 in (5 cm) in adult's CPR equally without consideration of patients' thoracic diameter and body size. If chest compression depth is too deeper (residual of chest diameter less than 2 cm), chest compression may not be helpful to patient but hurt intrathoracic organs and lead to complications. For lowbody-weight patients, an alternative chest compression depth of one-fourth of the external anterior to posterior thoracic depth is recommended [31].

### 5.2. Allowing complete chest recoil

Not only emphasizing chest compression rate and depth, but allowing total chest complete recoil at each chest compression is also mentioned by 2010 AHA guideline. Complete chest recoil makes negative thoracic pressure to draw venous blood back to the heart and thus increases preload of the heart, higher coronary perfusion pressure, and good cerebral perfusion pressure. Allowing complete chest recoil at each chest compression is suggested at the speed of at least 100 chest compressions/minute. But this condition will make rescuer easily fatigue because upward force needs to be full against gravity which induce major energy consumption of the rescuer. Fatigue of rescuer will lead to chest wall incomplete decompression and smaller chest compression depth and increase residual intrathoracic pressure during chest decompression stage. Increased residual intrathoracic pressure will obscure venous return, make less increase in systemic arterial pressure when chest compression, and decrease cerebral and coronary perfusion pressure. Even 1 minute of incomplete chest decompression during CPR will bring negative effect [32]. Changing sequential persons is an effective way to keep cardiopulmonary resuscitation quality by keeping chest compression rate at least 100/ minute and allowing complete chest recoil.

### 5.3. Minimalize chest compression interruptions

Minimalizing chest compression interruptions is an index of high quality of chest compression component. Chest compression phase replaces systolic pressure of the heart, and the recoil phase replaces diastolic pressure of the heart. Chest compression interruptions result in no cardiac support during CPR. This situation is called no flow time (NFT). Such chest compression interruptions make poor prognosis of OHCA [33, 34]. The change of the ventilation to chest compression ratio from 2:15 to 2:30 according to 2005 CPR guideline suggests to increase chest compression velocity per minute and minimalize interruptions induced by ventilation. These interruptions made 25% reduction in the NFT [35].

Chest compression is also interrupted by pulse and rhythm check. Cessation of chest compression for automated external defibrillators (AEDs) to analyze electrocardiogram can lead to 10% no flow time (NFT) events. When asystole and ventricular fibrillation (VF) are analyzed, additional confirmatory pulse checking makes delay chest compression. These two kinds of no flow times (NFTs) can be prevented by immediate chest compression when asystole is revealed by electrocardiogram or just defibrillated ventricular fibrillation (VF) rhythm. Filtering out artifact wave from chest compression by cardiac monitor or automated external defibrillator (AED) avoids chest compression interruptions and increases cardiopulmonary resuscitation (CPR) efficiency [36].

Pre-/post-defibrillation pauses may cause chest compression interruptions and create no flow times (NFTs) due to defibrillator charging, pulse and rhythm check, or lack of quick chest compressions [37]. Shortening pre-/post-defibrillation pauses of chest compression increases 13 fold chance of ROSC [38]. Besides, decrease pre-defibrillation pause of chest compression increases chance of successful defibrillation and effects of termination ventricular tachycardia (VT)/ventricular fibrillation (VF) situation [39]. Even now, a safe and effective tool for "handson" defibrillation solves chest compression interruption of pre-/post-defibrillation pause and increases chance of successful defibrillation. Though, it is still studied [40].

In out-of-hospital cardiac arrest (OHCA), transferring patient from arrest situation to ambulance is also a reason of no flow time (NFT) [41]. Rescuers should be educated that transferring cardiac arrest patient can lead to NFT. Besides, rescuer team should not move OHCA patient until ROSC is successful after giving professional advance life resuscitation or move OHCA patient with compressions and using Advance Cardiology Consultants and Diagnostics (ACCDs) [42].

Besides, many other reasons can influence the chest compression interruptions. Cardiopulmonary resuscitation scene has a high emotional stress; human behavior can cause nonspecific NFTs. Like poor leadership, poor task distribution by a leader who gives double or even triple orders which lead rescuer hard to member to produce high cognition load will result in poor rescuer concentration and poor awareness of CPR situations. The abovementions will cause nonspecific NFTs. In the contrast, if the leader gives rescuer members a single, clear order which can make rescuers decrease cognition load increases teamwork quality and decreases NFTs [43]. There are several common reasons causing NFTs [43], such as (1) rescuer fatigue and change chest compressor, (2) performing ventilation, (3) performing airway maintenance, (4) application CPR device, (5) pulse and rhythm check, (6) pre-/post-defibrillation pause, (7) performing vascular access, and (8) transferring patient to ambulance.

Rescuer fatigue and change chest compressor are the most common reasons to induce NFT events. Especially, chest compressor fatigue is usually found after 1 minute of CPR work. In 2010 AHA guideline, chest compressor change every 2 minutes is suggested. Changing chest compressors also interrupts chest compression. To minimize chest compression interruptions, chest compressor switch must be done within 5 seconds. If there are two rescuers, they should be positioned on either side of the patient. One rescuer should be ready and wait to change "working compressor" every 2 minutes [44].

### 5.4. Avoid excessive ventilation

chance of survival to hospital. Every 0.5 cm increase depth doubles the chance of successful resuscitation [29]. Enough depth of chest compression is also a key to survival. However, chest compression depth has a reverse relation to chest compression rate. The higher chest compression rate and the lower chest compression depth have been noted. If chest compression rate up to 145/minute is done, the depth of chest compression becomes unacceptable according to 2005

The 2010 AHA guideline suggests chest compression depth of at least 2 in (5 cm) in adult's CPR equally without consideration of patients' thoracic diameter and body size. If chest compression depth is too deeper (residual of chest diameter less than 2 cm), chest compression may not be helpful to patient but hurt intrathoracic organs and lead to complications. For lowbody-weight patients, an alternative chest compression depth of one-fourth of the external

Not only emphasizing chest compression rate and depth, but allowing total chest complete recoil at each chest compression is also mentioned by 2010 AHA guideline. Complete chest recoil makes negative thoracic pressure to draw venous blood back to the heart and thus increases preload of the heart, higher coronary perfusion pressure, and good cerebral perfusion pressure. Allowing complete chest recoil at each chest compression is suggested at the speed of at least 100 chest compressions/minute. But this condition will make rescuer easily fatigue because upward force needs to be full against gravity which induce major energy consumption of the rescuer. Fatigue of rescuer will lead to chest wall incomplete decompression and smaller chest compression depth and increase residual intrathoracic pressure during chest decompression stage. Increased residual intrathoracic pressure will obscure venous return, make less increase in systemic arterial pressure when chest compression, and decrease cerebral and coronary perfusion pressure. Even 1 minute of incomplete chest decompression during CPR will bring negative effect [32]. Changing sequential persons is an effective way to keep cardiopulmonary resuscitation quality by keeping chest compression rate at least 100/

Minimalizing chest compression interruptions is an index of high quality of chest compression component. Chest compression phase replaces systolic pressure of the heart, and the recoil phase replaces diastolic pressure of the heart. Chest compression interruptions result in no cardiac support during CPR. This situation is called no flow time (NFT). Such chest compression interruptions make poor prognosis of OHCA [33, 34]. The change of the ventilation to chest compression ratio from 2:15 to 2:30 according to 2005 CPR guideline suggests to increase chest compression velocity per minute and minimalize interruptions induced by ventilation.

Chest compression is also interrupted by pulse and rhythm check. Cessation of chest compression for automated external defibrillators (AEDs) to analyze electrocardiogram can lead to 10% no flow time (NFT) events. When asystole and ventricular fibrillation (VF) are analyzed,

anterior to posterior thoracic depth is recommended [31].

5.2. Allowing complete chest recoil

minute and allowing complete chest recoil.

5.3. Minimalize chest compression interruptions

These interruptions made 25% reduction in the NFT [35].

AHA guideline [30].

68 Resuscitation Aspects

In 2010 AHA guideline, rescue ventilation is less emphasized than before. During low blood flow due to cardiopulmonary resuscitation status, oxygen supply is mainly from limited blood flow, and chest compression presents as "working heart." Thus, chest compression is emphasized in the first few minutes of witnessed cardiac arrest [45]. Excessive ventilation increases high thoracic pressure which results in lower coronary perfusion pressure, decreased venous return, and poor survival rate [46]. In 2010 AHA guideline, suggested ventilator rate during CPR is giving two breaths (1 second each) during a brief (about 3–4 seconds) pause after is every 30 chest compressions [47].

In conclusion, chest compression is the key component of CPR. High quality of chest compression is the mostly important determination of ROSC which is the most important predictor of survival from cardiac arrest. Besides, high quality of chest compression combined by rate and depth, minimalizing chest interruptions, and avoiding excessive ventilation, is an important determination of survival with good neurological outcome [3].

### 6. Compression-only CPR

Compression-only CPR is easier to teach; it does not require mouth-to-mouth ventilation (which can be an impediment to bystanders starting CPR), and it reduces interruptions in chest compressions. Hupfl et al. [8] have conducted a systematic review and meta-analysis in two settings of CPR in OHCA patients—chest compression-only bystander CPR and standard bystander CPR (chest compression plus rescue ventilation). A primary meta-analysis included trials that patients of those trials were randomized to attribute to accept one of the two CPR techniques which are commended by dispatchers, and another meta-analysis included studies of chest compression-only CPR as observational cohort studies. Survival to hospital discharge was the primary outcome. The pooled data of three randomized trials revealed that chest compression-only CPR survival chance was greater (14% [211/1500]) than that of the standard CPR (12% [178/1531]; risk ratio 1.22, 95% CI 1.01–1.46). The absolute increase in survival was 2.4% (95% CI 0.1–4.9). In the secondary meta-analysis of seven observational cohort studies, no difference was recorded between the two CPR techniques (8% [223/2731] and 8% [863/11152]; risk ratio 0.96, 95% CI 0.83–1.11). They concluded that for adults with out-of-hospital cardiac arrest, instructions to bystanders from emergency medical services dispatch should focus on chest compression-only CPR.

A more recent review reported by Zhan et al. [6] have compared the effects of continuous chest compression CPR (with or without rescue breathing) versus conventional CPR plus rescue breathing (interrupted chest compression with pauses for breaths) of non-asphyxial OHCA in large scales of patients. They included three randomized controlled trials (RCTs) and one cluster RCT (with a total of 26,742 participants analyzed). According to CPR methods, this report divided CPR into "CPR administered by untrained bystander" and "CPR administered by a trained professional."

For the CPR administered by untrained bystander, bystanders administered CPR under telephone instruction from emergency services. They found that better OHCA patient survival to hospital discharge rate (2.4%; 14 versus 11.6%; RR 1.21, 95% confidence interval (CI) 1.01–1.46; 3 studies, 3031 participants) was those who received continuous chest compression CPR without rescue breathing compared with those who received interrupted chest compression with rescue breathing (ratio 15:2). For the CPR administered by a trained professional from emergency medical service (EMS) professionals, there were 23,711 participants who received either continuous chest compression CPR (100/minute) with asynchronous rescue breathing (10/minute) or interrupted chest compression with pauses for rescue breathing (ratio 30:2). Results revealed that lower risk of survival to hospital discharge was noted for continuous chest compression CPR with asynchronous rescue breathing (9.0%) compared with interrupted chest compression with rescue breathing (9.7%). Both have an adjusted risk difference (ARD) of 0.7%; 95% CI (1.5 to 0.1%) (moderate-quality evidence).

Return of spontaneous circulation is likely to be slightly lower in people treated with continuous chest compression CPR plus asynchronous rescue breathing (24.2 versus 25.3%; 1.1% (95% CI 2.4 to 0.1)) (high-quality evidence).

This report found that following OHCA, bystander-administered chest compression-only CPR, supported by telephone instruction, increases the proportion of people who survive to hospital discharge compared with conventional interrupted chest compression CPR plus rescue breathing. However, when CPR performed by EMS providers, continuous chest compressions plus asynchronous rescue breathing did not result in higher rates for survival to hospital discharge compared to interrupted chest compression plus rescue breathing [6]. Thus, due to these experiences, it is reasonable to suggest that bystander should perform CPR and as soon as possible (1) do basic life support protocol, if trained (in CPR) and willing and (2) do compression-only CPR, if untrained or unwilling to include ventilation. Healthcare professionals should perform CPR with combined compressions and ventilations.

Another animal study compared survival of VF-arrested swine treated with chest compression-only CPR or with realistic bystander CPR where each set of chest compressions was interrupted with a realistic 16 seconds for ventilations. Survival was 80% with chest compression-only CPR and 13% with standard bystander CPR [48]. Similar authors have performed their extensive efforts to advocate and teach chest compression-only CPR as part of cardiocerebral resuscitation for patients with primary cardiac arrest in the state of Arizona. They found that for OHCA patients, the survival rate was 7.8% in those receiving guidelines of CPR and 13.3% for those who received chest compression-only CPR. In the subset of patients with a witnessed cardiac arrest and a shockable rhythm, the survival rate was 17.7% in those receiving guidelines of CPR and 34% in those patients receiving chest compression-only CPR [49, 50]. These findings support the usefulness of chest compression-only CPR in managing OHCA patients.

### 7. Future direction

flow, and chest compression presents as "working heart." Thus, chest compression is emphasized in the first few minutes of witnessed cardiac arrest [45]. Excessive ventilation increases high thoracic pressure which results in lower coronary perfusion pressure, decreased venous return, and poor survival rate [46]. In 2010 AHA guideline, suggested ventilator rate during CPR is giving two breaths (1 second each) during a brief (about 3–4 seconds) pause after is

In conclusion, chest compression is the key component of CPR. High quality of chest compression is the mostly important determination of ROSC which is the most important predictor of survival from cardiac arrest. Besides, high quality of chest compression combined by rate and depth, minimalizing chest interruptions, and avoiding excessive ventilation, is an important

Compression-only CPR is easier to teach; it does not require mouth-to-mouth ventilation (which can be an impediment to bystanders starting CPR), and it reduces interruptions in chest compressions. Hupfl et al. [8] have conducted a systematic review and meta-analysis in two settings of CPR in OHCA patients—chest compression-only bystander CPR and standard bystander CPR (chest compression plus rescue ventilation). A primary meta-analysis included trials that patients of those trials were randomized to attribute to accept one of the two CPR techniques which are commended by dispatchers, and another meta-analysis included studies of chest compression-only CPR as observational cohort studies. Survival to hospital discharge was the primary outcome. The pooled data of three randomized trials revealed that chest compression-only CPR survival chance was greater (14% [211/1500]) than that of the standard CPR (12% [178/1531]; risk ratio 1.22, 95% CI 1.01–1.46). The absolute increase in survival was 2.4% (95% CI 0.1–4.9). In the secondary meta-analysis of seven observational cohort studies, no difference was recorded between the two CPR techniques (8% [223/2731] and 8% [863/11152]; risk ratio 0.96, 95% CI 0.83–1.11). They concluded that for adults with out-of-hospital cardiac arrest, instructions to bystanders from emergency medical services dispatch should focus on

A more recent review reported by Zhan et al. [6] have compared the effects of continuous chest compression CPR (with or without rescue breathing) versus conventional CPR plus rescue breathing (interrupted chest compression with pauses for breaths) of non-asphyxial OHCA in large scales of patients. They included three randomized controlled trials (RCTs) and one cluster RCT (with a total of 26,742 participants analyzed). According to CPR methods, this report divided CPR into "CPR administered by untrained bystander" and "CPR administered

For the CPR administered by untrained bystander, bystanders administered CPR under telephone instruction from emergency services. They found that better OHCA patient survival to hospital discharge rate (2.4%; 14 versus 11.6%; RR 1.21, 95% confidence interval (CI) 1.01–1.46; 3 studies, 3031 participants) was those who received continuous chest compression CPR

every 30 chest compressions [47].

70 Resuscitation Aspects

6. Compression-only CPR

chest compression-only CPR.

by a trained professional."

determination of survival with good neurological outcome [3].

It has been reported that the use of Internet-based CPR education and certification may expand current training program coverage, according to the expanding use of Internet via television, mobile telephone, and other personal devices [51]. In certain conditions, simpler procedure of by bystander resuscitation, like chest compression-only CPR, may broaden participation and remain a field that needs further studies [20]. For EMS-CPR and resuscitation companies, college or institute of EMT training systems, and other professional CPR providers, the use of accurate simulation with video recording and debriefing may be very useful in resuscitation training; the use of such patient simulators is rapidly an expanding area that deserves a lot of attention [52, 53].

### 8. Conclusion

OHCA remains a common event and is associated with high mortality. Strengthening the chain of survival with prompt initiation of high-quality CPR, minimizing interruptions in chest compressions and organized post-resuscitation care, provides focused opportunities to improve outcomes. CPR must be started as soon as possible after a victim of OHCA, and bystander should (1) do full CPR, if trained (in CPR) and willing and (2) do chest compression-only CPR, if untrained or unwilling to perform mouth-to-month ventilation. Healthcare professionals should perform CPR with combined compressions and ventilations. Improved survival rates depend on a public trained and motivated to recognize the emergency, activate EMS or the emergency response system, initiate high-quality CPR, and use an AED if available.

### Author details

Hui-Chun Chen<sup>1</sup> and Shoa-Lin Lin2,3\*

\*Address all correspondence to: sllin@yuanhosp.com.tw

1 Department of Internal Medicine, Kaohsiung Municipal Min-Sheng Hospital, Kaohsiung City, Taiwan

2 Division of Cardiology, Department of Internal Medicine, Yuan's General Hospital, Kaohsiung City, Taiwan

3 National Defense Medical College, Taipei, Taiwan

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remain a field that needs further studies [20]. For EMS-CPR and resuscitation companies, college or institute of EMT training systems, and other professional CPR providers, the use of accurate simulation with video recording and debriefing may be very useful in resuscitation training; the use of such patient simulators is rapidly an expanding area that deserves a lot of

OHCA remains a common event and is associated with high mortality. Strengthening the chain of survival with prompt initiation of high-quality CPR, minimizing interruptions in chest compressions and organized post-resuscitation care, provides focused opportunities to improve outcomes. CPR must be started as soon as possible after a victim of OHCA, and bystander should (1) do full CPR, if trained (in CPR) and willing and (2) do chest compression-only CPR, if untrained or unwilling to perform mouth-to-month ventilation. Healthcare professionals should perform CPR with combined compressions and ventilations. Improved survival rates depend on a public trained and motivated to recognize the emergency, activate EMS or the emergency

1 Department of Internal Medicine, Kaohsiung Municipal Min-Sheng Hospital, Kaohsiung

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2 Division of Cardiology, Department of Internal Medicine, Yuan's General Hospital,

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72 Resuscitation Aspects

8. Conclusion

Author details

City, Taiwan

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Hui-Chun Chen<sup>1</sup> and Shoa-Lin Lin2,3\*

\*Address all correspondence to: sllin@yuanhosp.com.tw

3 National Defense Medical College, Taipei, Taiwan

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Provisional chapter

### **Audiovisual Feedback Devices for Chest Compression Quality during CPR** Audiovisual Feedback Devices for Chest Compression Quality during CPR

DOI: 10.5772/intechopen.70742

Digna M. González-Otero, Sofía Ruiz de Gauna, Jesus M. Ruiz, José Julio Gutiérrez, Purificación Saiz and Mikel Leturiondo Digna M. González-Otero, Sofía Ruiz de Gauna, Jesus M. Ruiz, José Julio Gutiérrez,

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

Purificación Saiz and Mikel Leturiondo

http://dx.doi.org/10.5772/intechopen.70742

### Abstract

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76 Resuscitation Aspects

During cardiopulmonary resuscitation (CPR), chest compression quality is the key for patient survival. However, several studies have shown that both professionals and laypeople often apply CPR at improper rates and depths. The use of real-time feedback devices increases adherence to CPR quality guidelines. This chapter explores new alternatives to provide feedback on the quality of chest compressions during CPR. First, we describe and evaluate three methods to compute chest compression depth and rate using exclusively the chest acceleration. To evaluate the accuracy of the methods, we used episodes of simulated cardiac arrest acquired in a manikin model. One of the methods, based on the spectral analysis of the acceleration, was particularly accurate in a wide range of conditions. Then, we assessed the feasibility of using the transthoracic impedance (TI) signal acquired through defibrillation pads to provide feedback on chest compression depth and rate. For that purpose, we retrospectively analyzed three databases of out-of-hospital cardiac arrest episodes. When a wide variety of patients and rescuers were included, TI could not be used to reliably estimate the compression depth. However, compression rate could be accurately estimated. Development of simpler methods to provide feedback on CPR quality could contribute to the widespread of these devices.

Keywords: cardiopulmonary resuscitation, chest compression quality, compression depth, compression rate, feedback devices, chest acceleration, thoracic impedance

### 1. Introduction

The sequence of actions linking a victim of out-of-hospital cardiac arrest with survival is described by the chain of survival, which consists of four independent links: early activation

© 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited.

of the emergency medical services, early cardiopulmonary resuscitation (CPR), early defibrillation, and early advanced care. The four links of the chain of survival are important, but early CPR and early defibrillation are pivotal for a successful outcome of the patient [1]. CPR consists of cycles of chest compressions and ventilations delivered to the patient to artificially maintain a minimal flow of oxygenated blood to the vital organs, whereas defibrillation consists in the passage of electrical current through the myocardium (cardiac muscle) to terminate certain lethal arrhythmias. In out-of-hospital settings, early defibrillation is normally procured using an automated external defibrillator (AED).

There is a strong evidence that the quality of chest compressions is related to the chance of successful defibrillation [2–4]. Current resuscitation guidelines [1] emphasize the importance of providing chest compressions with an adequate depth (between 5 and 6 cm) and rate (between 100 and 120 compressions per minute [cpm]), completely releasing the chest between compressions and minimizing interruptions. However, several studies have shown that both professionals and laypeople often apply CPR at improper rates and depths [5, 6].

In an effort to alleviate this problem, since 2010, resuscitation guidelines recommend monitoring CPR quality and using metronomes and real-time feedback systems to guide rescuers during resuscitation attempts [7]. Metronomes generate regular audible beats that help rescuers to follow the rhythm, while feedback devices are more sophisticated; they measure CPR performance in real time and provide audiovisual messages to guide the rescuer toward target depth and rate. The clinical studies conducted to date had an insufficient power to demonstrate improved survival with the use of feedback devices [8]. As a consequence, ERC guidelines 2015 recommend the use of CPR feedback devices as part of a broader system of care that should include comprehensive CPR quality improvement initiatives, rather than as an isolated intervention. There is, however, strong evidence that feedback improves chest compression quality, [9–12] which has been linked to survival from cardiac arrest [5, 8].

This chapter explores new alternatives to provide feedback on the quality of chest compressions during CPR. First, we briefly describe the history of feedback devices and the different technologies used. Then, we present three methods to provide feedback on chest compression depth and rate based solely on chest acceleration. One of the methods presented particularly a high accuracy in a wide range of conditions and is further discussed in three challenging scenarios. Finally, we assessed the feasibility of using the transthoracic impedance (TI) signal acquired through defibrillation pads to provide feedback on chest compression depth and rate.

### 2. History of feedback devices

The first CPR feedback devices were mechanical and used force or pressure sensors to provide feedback on chest compression depth [13]. Devices in this category include CPRplus (Kelly Medical Products, Princeton, USA), CPREzy (Health Affairs, London, England), and the more recent Cardio First Angel (Schiller, Baar, Switzerland). These systems guide the rescuer toward the target depth based on the force applied on the chest for each compression. However, stiffness of the chest is not linear [14] and varies among individuals. Tomlinson et al. [15] simultaneously measured compression force and depth in 91 adult out-of-hospital cardiac arrest patients. In the studied population, the force required to achieve 38 mm varied from 10 to 54 kg. Even if some of the devices in this category take into account the approximate size of the patient, the wide variation in chest wall elasticity and its changes with time impede an accurate estimation of compression depth from compression force.

of the emergency medical services, early cardiopulmonary resuscitation (CPR), early defibrillation, and early advanced care. The four links of the chain of survival are important, but early CPR and early defibrillation are pivotal for a successful outcome of the patient [1]. CPR consists of cycles of chest compressions and ventilations delivered to the patient to artificially maintain a minimal flow of oxygenated blood to the vital organs, whereas defibrillation consists in the passage of electrical current through the myocardium (cardiac muscle) to terminate certain lethal arrhythmias. In out-of-hospital settings, early defibrillation is normally

There is a strong evidence that the quality of chest compressions is related to the chance of successful defibrillation [2–4]. Current resuscitation guidelines [1] emphasize the importance of providing chest compressions with an adequate depth (between 5 and 6 cm) and rate (between 100 and 120 compressions per minute [cpm]), completely releasing the chest between compressions and minimizing interruptions. However, several studies have shown that both

In an effort to alleviate this problem, since 2010, resuscitation guidelines recommend monitoring CPR quality and using metronomes and real-time feedback systems to guide rescuers during resuscitation attempts [7]. Metronomes generate regular audible beats that help rescuers to follow the rhythm, while feedback devices are more sophisticated; they measure CPR performance in real time and provide audiovisual messages to guide the rescuer toward target depth and rate. The clinical studies conducted to date had an insufficient power to demonstrate improved survival with the use of feedback devices [8]. As a consequence, ERC guidelines 2015 recommend the use of CPR feedback devices as part of a broader system of care that should include comprehensive CPR quality improvement initiatives, rather than as an isolated intervention. There is, however, strong evidence that feedback improves chest compression

This chapter explores new alternatives to provide feedback on the quality of chest compressions during CPR. First, we briefly describe the history of feedback devices and the different technologies used. Then, we present three methods to provide feedback on chest compression depth and rate based solely on chest acceleration. One of the methods presented particularly a high accuracy in a wide range of conditions and is further discussed in three challenging scenarios. Finally, we assessed the feasibility of using the transthoracic impedance (TI) signal acquired through defibrillation pads to provide feedback on chest compression depth and rate.

The first CPR feedback devices were mechanical and used force or pressure sensors to provide feedback on chest compression depth [13]. Devices in this category include CPRplus (Kelly Medical Products, Princeton, USA), CPREzy (Health Affairs, London, England), and the more recent Cardio First Angel (Schiller, Baar, Switzerland). These systems guide the rescuer toward the target depth based on the force applied on the chest for each compression. However, stiffness of the chest is not linear [14] and varies among individuals. Tomlinson et al. [15]

professionals and laypeople often apply CPR at improper rates and depths [5, 6].

quality, [9–12] which has been linked to survival from cardiac arrest [5, 8].

2. History of feedback devices

procured using an automated external defibrillator (AED).

78 Resuscitation Aspects

To overcome the limitations of force and pressure sensors, electronic systems based on accelerometers were developed. These devices sense the acceleration of the patient's chest during CPR, and they process it in real time to obtain compression depth. By definition, acceleration is the first derivative of velocity with respect to time, and velocity is the first derivative of displacement. Consequently, chest displacement can be obtained from acceleration by applying double integration. However, integration is an inherently unstable process: small integration errors rapidly accumulate causing a significant drift in displacement that impedes accurate estimation of the compression depth. Figure 1 illustrates the problem of double integration of the chest acceleration with a record acquired while chest compressions were provided to a resuscitation manikin. The acceleration signal (top panel) and the reference compression depth signal obtained from a displacement sensor placed inside the manikin's chest (bottom panel, solid line) were registered. The second panel shows the reference velocity signal computed differentiating the reference compression depth signal (solid line), and the velocity signal computed by numerically integrating the acceleration signal (dashed line). Integration errors quickly accumulate, and during the last seconds, the computed velocity presents a noticeable offset with respect to the reference signal. When numeric integration is performed again, this offset leads to big errors in the computed displacement (bottom panel, dashed line), of more than 20 cm after only 8 s in this example.

Figure 1. Integration errors in the displacement signal after the application of direct double integration to the acceleration signal.

A possible strategy to reduce the accumulation of integration errors would be to perform the integration for small signal segments, for example, for each compression cycle. For that purpose, the offset of each chest compression should be first identified, and the integration should be reset by applying boundary conditions after each cycle, that is, setting velocity and displacement at those points to zero. Over the last decade, several mechanisms to identify the offset of chest compressions have been conceived, giving rise to complex commercial devices that incorporate additional sensors or use elaborate signal processing techniques. For example, PocketCPR (Zoll Medical, Chelmsford, USA) applies signal processing techniques to set boundary conditions and compensate integrating drift, while CPRmeter (Laerdal Medical, Stavanger, Norway) incorporates an additional force sensor. Both devices are rigid and must be placed between the chest of the patient and the rescuer's hands during CPR to measure chest acceleration.

More recently, Physio-Control (Redmond, USA) presented TrueCPR, a solution to provide feedback on chest compression rate, depth, and chest release based on triaxial magnetic field induction. The device comprises two rigid pads: one of them is positioned between the rescuer's hands and the chest of the patient during CPR, and the other one, longer and flatter, beneath the patient's back. Feedback metrics are estimated from the changes in magnetic field between both pads during CPR. The main disadvantage of this device is that it is bulkier than the others and also rigid.

### 3. Use of the acceleration signal for chest compression quality

This section briefly describes three methods to compute chest compression rate and depth and to provide CPR feedback to the rescuers using only chest acceleration. For a more detailed description of the methods, see reference [16]. The first method derives from the traditional approach; it consists in applying double integration to compute the compression depth signal. In our proposal, integration is approximated using a stable band-pass filter (BPF) that performs integration while suppressing low frequencies of the signal. The second and third methods do not require computing the compression depth signal: the second method computes velocity to calculate a compression rate and depth value for each compression, while the third one computes rate and depth from the spectral analysis of the acceleration signal (SAA). We used episodes of simulated cardiac arrest acquired using a resuscitation manikin to evaluate the accuracy of the three methods.

### 3.1. Experimental set-up and data collection

We equipped a Resusci Anne QCPR manikin (Laerdal Medical, Norway) with a photoelectric sensor to register the reference compression depth signal. Chest compressions were delivered in the center of the manikin's chest with a triaxial accelerometer encased in a metal box placed beneath the rescuer's hands. The reference compression depth signal and the three axes of the acceleration were digitized and recorded using a National Instruments (Austin, USA) acquisition card connected to a laptop computer. Figure 2 shows the experimental set-up used to perform the data collection.

Audiovisual Feedback Devices for Chest Compression Quality during CPR http://dx.doi.org/10.5772/intechopen.70742 81

Figure 2. Experimental setup: Resusci Anne QCPR manikin fitted with a displacement sensor, triaxial accelerometer encased in a metallic box, acquisition card, and laptop computer.

Twenty-eight volunteers participated in the recording sessions. They were grouped in couples, and for each couple, four 10-min episodes were recorded. During each episode, volunteers alternated providing 2-min CPR series, each series involving 30 compressions with 5-s pauses in between. A total of 56 episodes were acquired. The experimental protocol was approved by the ethical committee for research involving human subjects of the University of the Basque Country (CEISH UPV/EHU).

### 3.2. Methods to estimate chest compression rate and depth

### 3.2.1. Band-pass filter

A possible strategy to reduce the accumulation of integration errors would be to perform the integration for small signal segments, for example, for each compression cycle. For that purpose, the offset of each chest compression should be first identified, and the integration should be reset by applying boundary conditions after each cycle, that is, setting velocity and displacement at those points to zero. Over the last decade, several mechanisms to identify the offset of chest compressions have been conceived, giving rise to complex commercial devices that incorporate additional sensors or use elaborate signal processing techniques. For example, PocketCPR (Zoll Medical, Chelmsford, USA) applies signal processing techniques to set boundary conditions and compensate integrating drift, while CPRmeter (Laerdal Medical, Stavanger, Norway) incorporates an additional force sensor. Both devices are rigid and must be placed between the chest of the patient and the rescuer's hands during CPR to measure

More recently, Physio-Control (Redmond, USA) presented TrueCPR, a solution to provide feedback on chest compression rate, depth, and chest release based on triaxial magnetic field induction. The device comprises two rigid pads: one of them is positioned between the rescuer's hands and the chest of the patient during CPR, and the other one, longer and flatter, beneath the patient's back. Feedback metrics are estimated from the changes in magnetic field between both pads during CPR. The main disadvantage of this device is that it is bulkier than

This section briefly describes three methods to compute chest compression rate and depth and to provide CPR feedback to the rescuers using only chest acceleration. For a more detailed description of the methods, see reference [16]. The first method derives from the traditional approach; it consists in applying double integration to compute the compression depth signal. In our proposal, integration is approximated using a stable band-pass filter (BPF) that performs integration while suppressing low frequencies of the signal. The second and third methods do not require computing the compression depth signal: the second method computes velocity to calculate a compression rate and depth value for each compression, while the third one computes rate and depth from the spectral analysis of the acceleration signal (SAA). We used episodes of simulated cardiac arrest acquired using a resuscitation manikin to evalu-

We equipped a Resusci Anne QCPR manikin (Laerdal Medical, Norway) with a photoelectric sensor to register the reference compression depth signal. Chest compressions were delivered in the center of the manikin's chest with a triaxial accelerometer encased in a metal box placed beneath the rescuer's hands. The reference compression depth signal and the three axes of the acceleration were digitized and recorded using a National Instruments (Austin, USA) acquisition card connected to a laptop computer. Figure 2 shows the experimental set-up used to

3. Use of the acceleration signal for chest compression quality

chest acceleration.

80 Resuscitation Aspects

the others and also rigid.

ate the accuracy of the three methods.

perform the data collection.

3.1. Experimental set-up and data collection

There are a number of discrete integration algorithms available, the most common one being the trapezoidal rule, because of its trade-off between simplicity and accuracy. Analytically, the implementation of this rule derives in an unstable linear system [16]. In practice, that means that small low-frequency components in the input signal generate low-frequency components in the output with amplitude that increases with time. If no technique is applied to compensate this accumulation of error in the output signal, the system could suffer a numeric overflow.

Our first approach consists in approximating the integration by a stable band-pass filter, designed as the series connection of a high-pass filter and the trapezoidal rule filter, which presents a low-pass response. The high-pass filter is aimed at compensating the instability of the trapezoidal rule filter for low frequencies. Figure 3 shows the magnitude of the frequency response of the band-pass filter, HBPF(f), represented by a solid line. Note that for frequencies above 0.6 Hz, the system matches the ideal response of the trapezoidal rule, depicted with a dashed line, whereas for low frequencies, it is stable (it does not tend to infinity, as opposed to the trapezoidal rule response).

Figure 3. Frequency response of the band-pass filter (solid line) compared to the ideal frequency response of the trapezoidal rule filter (dashed line).

Figure 4 illustrates the process of computing compression depth with this method. First, the acceleration signal a(t) (first panel) is processed with the band-pass filter to obtain velocity, v(t) (second panel). Then, this process is repeated with the velocity to obtain the computed compression depth signal sc(t) (third panel). Because of the suppression of the low-frequency components and the waveform distortion caused by the filtering process, sc(t) and the reference compression depth signal s(t) (fourth panel) have different waveforms. However, compression depth and rate can be easily computed by applying a peak detector to sc(t) and measuring the peak-to-peak amplitude and the distance between the peaks, respectively. Compression rate is computed as the inverse of the distance between two consecutive peaks,

Figure 4. BPF method, based on band-pass filtering.

expressed in compressions per minute (cpm). In Figure 4, the detected compressions and their corresponding depths are depicted by vertical lines in the third and fourth panels.

### 3.2.2. Detection of zero-crossing instants in the velocity signal (ZCV)

In this second method, the compression rate and depth values are directly calculated from the velocity signal, without computing the compression depth signal. For that purpose, the bandpass filter described in the previous section is applied to the acceleration once to obtain the velocity signal. The resulting signal is quite stable and can be processed to identify the zerocrossing instants from positive to negative, which represent the onset of each compression cycle (marked by circles in the second panel of Figure 5) and the zero-crossing instants from negative to positive, which correspond to the points of maximum displacement of the chest (marked by crosses in the second panel). For each compression cycle, the compression depth is computed as the area of the velocity signal between the onset and the maximum displacement point (shadowed in the second panel of the figure). Finally, the rate of the chest compressions can be computed as the inverse of the interval between two consecutive zero-crossing instants from positive to negative. In the bottom panel of Figure 5, the computed depth values (represented by vertical lines) are drawn over the reference compression depth signal for comparison.

### 3.2.3. Spectral analysis of the acceleration signal

Figure 4 illustrates the process of computing compression depth with this method. First, the acceleration signal a(t) (first panel) is processed with the band-pass filter to obtain velocity, v(t) (second panel). Then, this process is repeated with the velocity to obtain the computed compression depth signal sc(t) (third panel). Because of the suppression of the low-frequency components and the waveform distortion caused by the filtering process, sc(t) and the reference compression depth signal s(t) (fourth panel) have different waveforms. However, compression depth and rate can be easily computed by applying a peak detector to sc(t) and measuring the peak-to-peak amplitude and the distance between the peaks, respectively. Compression rate is computed as the inverse of the distance between two consecutive peaks,

Figure 3. Frequency response of the band-pass filter (solid line) compared to the ideal frequency response of the

frequency (Hz)

time (s)

0 2 4 6 8

0 1 2 3


trapezoidal rule filter (dashed line).

82 Resuscitation Aspects

*a*(*t*) (m/s2)

*v*(*t*) (cm/s)

*s*c(*t*) (mm)

*s*(*t*) (mm)

10 0 -10

50

0


25

0



Figure 4. BPF method, based on band-pass filtering.

0

2

1

0

In this third method, neither the compression depth nor the velocity signal is computed by integration. Instead of that, average compression rate and depth values are computed every 2 s by applying spectral analysis to the acceleration signal [17]. The basis of this method is the assumption that during short intervals with continuous chest compressions, the acceleration

Figure 5. ZCV method, based on the analysis of velocity.

and the displacement signals are quasi-periodic. Consequently, both signals can be modeled as a periodic acceleration and a periodic depth, with a fundamental frequency that represents the average frequency of the chest compressions during the interval. We modeled each 2-s segment of the acceleration and displacement signals using the first three harmonics of their Fourier series representation, without considering the direct current component. Figure 6 illustrates the procedure followed to apply this method. We first computed the fast Fourier transform (FFT) of the windowed acceleration signal and estimated the module and phase of the three first harmonic components of the acceleration. In the example shown in the figure, the selected window is shaded in the first panel, and its FFT with the identified harmonics is shown in the second panel. Taking into account that acceleration is the second derivative of displacement, when both signals are modeled as periodic, the amplitudes and phases of the spectral components of the compression depth can be derived from the ones of the acceleration. Using these values, a periodic version of the chest displacement during the analysis window can be reconstructed. This last step is represented in the third panel of Figure 6. The reference compression depth signal is plotted using a solid line, and the reconstructed signal for the selected window is represented by a dashed line. The reconstructed signal is periodic; i.e., it has the same amplitude for all the compressions, which represent the average compression depth during the analysis window. Average compression rate for each 2-s analysis window is computed from the fundamental frequency of the acceleration, fcc.

#### 3.3. Results

Panel (A) of Figure 7 shows the boxplots of the error in the estimation of compression depth for each of the methods. On each box, the central mark is the median, and the edges of the box

Figure 6. SAA method, based on the spectral analysis of the acceleration.

Audiovisual Feedback Devices for Chest Compression Quality during CPR http://dx.doi.org/10.5772/intechopen.70742 85

Figure 7. Boxplots of the global error in depth (A) and in rate (B) for the three methods.

are the percentiles 25 and 75, P<sup>25</sup> and P75, respectively. The whiskers extend to the most extreme data points not considered outliers i.e., within the 1.5 interquartile range (IQR) interval. Differences in the errors between methods were statistically significant (p < 0.001). SAA provided the highest accuracy, while BPF and ZCV displayed a slight tendency to overestimate depth values. Median (P25-P75) unsigned percent error in depth calculation for each method was 5.9 (2.8–10.3), 6.3 (2.9–11.3), and 2.5 (1.2–4.4)%.

Boxplots of the error in rate estimation are represented in panel (B) of Figure 7. For the ZCV method, errors were clearly concentrated around zero. Median (P25-P75) unsigned percent error in rate calculation was 1.7 (0.0–2.3), 0.0 (0.0–2.0), and 0.9 (0.4–1.6)% for BPF, ZCV, and SAA, respectively. Differences between methods in error in rate estimation were not statistically significant (p = 0.49).

#### 3.4. Discussion

and the displacement signals are quasi-periodic. Consequently, both signals can be modeled as a periodic acceleration and a periodic depth, with a fundamental frequency that represents the average frequency of the chest compressions during the interval. We modeled each 2-s segment of the acceleration and displacement signals using the first three harmonics of their Fourier series representation, without considering the direct current component. Figure 6 illustrates the procedure followed to apply this method. We first computed the fast Fourier transform (FFT) of the windowed acceleration signal and estimated the module and phase of the three first harmonic components of the acceleration. In the example shown in the figure, the selected window is shaded in the first panel, and its FFT with the identified harmonics is shown in the second panel. Taking into account that acceleration is the second derivative of displacement, when both signals are modeled as periodic, the amplitudes and phases of the spectral components of the compression depth can be derived from the ones of the acceleration. Using these values, a periodic version of the chest displacement during the analysis window can be reconstructed. This last step is represented in the third panel of Figure 6. The reference compression depth signal is plotted using a solid line, and the reconstructed signal for the selected window is represented by a dashed line. The reconstructed signal is periodic; i.e., it has the same amplitude for all the compressions, which represent the average compression depth during the analysis window. Average compression rate for each 2-s analysis win-

dow is computed from the fundamental frequency of the acceleration, fcc.

*<sup>A</sup> <sup>A</sup>*<sup>3</sup> <sup>2</sup>

Figure 6. SAA method, based on the spectral analysis of the acceleration.

*A*1

Panel (A) of Figure 7 shows the boxplots of the error in the estimation of compression depth for each of the methods. On each box, the central mark is the median, and the edges of the box

time (s)

frequency (Hz)

time (s)

0 1 2 3 4 5 6 7 8

0 *f*cc 5 10 15 20 25

0 2 4 6 8

3.3. Results

84 Resuscitation Aspects

*a*(*t*) (m/s2)


*s*(*t*) (mm)

10 0 -10

4

2

0

0


This section presents three strategies for feedback on the rate and depth of chest compressions during CPR by processing exclusively the acceleration signal and assesses their accuracy in a simulated manikin scenario.

The BPF and ZCV tended to overestimate chest compression depth and presented errors above 5 mm in 25% of the compressions. The SAA method, in contrast, was very accurate and not biased, with an error above 5 mm in only about 5% of the cases.

Percent error in rate estimation was very low for the three methods (median of 1.7, 0.0, and 0.9% for BPF, ZCV, and SAA, respectively). Errors of BPF and ZCV methods were mainly caused by the filter transient, particularly at the beginning of each compression series. This influence was higher for the BPF method, in which the filter was applied twice.

Most current CPR feedback devices rely on accelerometry and double integration to estimate chest compression depth. Manufacturers have designed different solutions for the instability problem, often protected by patent rights, based on either using additional pressure or force sensors to detect the onset of each compression cycle, or on advanced filtering techniques requiring reference signals. All these solutions lead to complex devices, limiting their widespread use in the practice, especially for bystanders and first responders to a cardiac arrest.

The methods discussed in this section are based solely on accelerometry and could lead to simpler, flexible, and cheaper devices. For its simplicity and accuracy, the method based on the spectral analysis of the acceleration might be a good candidate for implementation. To further test this method in challenging scenarios, we conducted three additional studies to evaluate the accuracy of the method: (1) when chest compressions were provided to a patient laying on a soft surface, (2) when the feedback device was attached to the rescuer's back of the hand, or to the wrist, or to the forearm, instead of being placed in the usual position between the chest and the rescuer's hands, and (3) when CPR was performed in a moving vehicle, particularly in a moving long-distance train.

When the patient is lying on a mattress or on any soft surface, accelerometer feedback devices overestimate chest compression depth, [18] as the calculated depth corresponds to the total displacement of the chest, that is, the sternal-spinal displacement plus the mattress displacement. This would lead to erroneous feedback, which could contribute to the delivery of shallow chest compressions. We proposed a solution based on two accelerometers incorporating the spectral method. One is placed on the chest to measure the total displacement of the chest, while the other one is placed at the back of the patient and measures the mattress compression distance. The difference between both measurements will correspond to the actual compression depth. This method presented a high accuracy. Detailed results are presented in reference [19].

Current positioning of CPR feedback devices may cause soft-tissue damage to the patient or to the rescuer, along with wrist discomfort. We analyzed the accuracy of the spectral method when the accelerometer was placed in alternative positions that reduce discomfort: the rescuer's back of the hand, the wrist, and the forearm. We compared these results with those obtained in the traditional position and concluded that positioning the device at the back of the hand was the optimal sensor position. Fixed to the wrist or to the forearm, the sensor was subjected to swinging movements or hands separation from the chest, which caused a large overestimation of compression depth. Readers are encouraged to consult reference [20] for further details.

Finally, we studied the performance of the spectral method when tested in a moving longdistance train. Currently, defibrillators are increasingly being installed in public transportation settings, in an effort to provide an early response to sudden cardiac arrest. Early CPR should be also administered in such scenarios, and the CPR feedback devices could increase CPR quality, but to date how the movement of the vehicles affects accelerometer-based devices has not been sufficiently studied. We tested the spectral method in a long distance train with a manikin setup and compared the results with those obtained in static conditions. Errors in depth estimation tended higher in the train, but no statistical differences were found. Rate estimation was very accurate. Our conclusion was that, as the spectral method does not consider frequency components of the acceleration out of the range of chest compressions (1–10 Hz), movement did not affect performance [21].

In conclusion, the spectral method was accurate to compute chest compression depth and rate in a wide set of conditions and could be used to develop a new CPR feedback device. However, the method is not capable of detecting inadequate rescuer's leaning between compressions. Leaning decreases the blood flow throughout the heart and can decrease venous return and cardiac output. Guidelines recommend minimizing leaning, but human studies show that a majority of rescuers often lean during CPR and do not allow the chest to recoil fully between compressions. This is the current major drawback of any attempt to derive feedback only from accelerometers. For this reason, some commercial accelerometer-based devices use force sensors to provide feedback on this quality parameter.

### 4. Transthoracic impedance signal for chest compression quality

The methods discussed in this section are based solely on accelerometry and could lead to simpler, flexible, and cheaper devices. For its simplicity and accuracy, the method based on the spectral analysis of the acceleration might be a good candidate for implementation. To further test this method in challenging scenarios, we conducted three additional studies to evaluate the accuracy of the method: (1) when chest compressions were provided to a patient laying on a soft surface, (2) when the feedback device was attached to the rescuer's back of the hand, or to the wrist, or to the forearm, instead of being placed in the usual position between the chest and the rescuer's hands, and (3) when CPR was performed in a moving vehicle, particularly in

When the patient is lying on a mattress or on any soft surface, accelerometer feedback devices overestimate chest compression depth, [18] as the calculated depth corresponds to the total displacement of the chest, that is, the sternal-spinal displacement plus the mattress displacement. This would lead to erroneous feedback, which could contribute to the delivery of shallow chest compressions. We proposed a solution based on two accelerometers incorporating the spectral method. One is placed on the chest to measure the total displacement of the chest, while the other one is placed at the back of the patient and measures the mattress compression distance. The difference between both measurements will correspond to the actual compression depth. This method presented a high accuracy. Detailed results are

Current positioning of CPR feedback devices may cause soft-tissue damage to the patient or to the rescuer, along with wrist discomfort. We analyzed the accuracy of the spectral method when the accelerometer was placed in alternative positions that reduce discomfort: the rescuer's back of the hand, the wrist, and the forearm. We compared these results with those obtained in the traditional position and concluded that positioning the device at the back of the hand was the optimal sensor position. Fixed to the wrist or to the forearm, the sensor was subjected to swinging movements or hands separation from the chest, which caused a large overestimation of compression depth. Readers are encouraged to consult reference [20] for further details.

Finally, we studied the performance of the spectral method when tested in a moving longdistance train. Currently, defibrillators are increasingly being installed in public transportation settings, in an effort to provide an early response to sudden cardiac arrest. Early CPR should be also administered in such scenarios, and the CPR feedback devices could increase CPR quality, but to date how the movement of the vehicles affects accelerometer-based devices has not been sufficiently studied. We tested the spectral method in a long distance train with a manikin setup and compared the results with those obtained in static conditions. Errors in depth estimation tended higher in the train, but no statistical differences were found. Rate estimation was very accurate. Our conclusion was that, as the spectral method does not consider frequency components of the acceleration out of the range of chest compressions

In conclusion, the spectral method was accurate to compute chest compression depth and rate in a wide set of conditions and could be used to develop a new CPR feedback device. However, the method is not capable of detecting inadequate rescuer's leaning between compressions. Leaning decreases the blood flow throughout the heart and can decrease venous

a moving long-distance train.

86 Resuscitation Aspects

presented in reference [19].

(1–10 Hz), movement did not affect performance [21].

Most defibrillators, particularly the simplest devices, acquire only the ECG and the TI signal through the defibrillation pads. A straightforward solution for monitoring and providing feedback on the quality of chest compressions could be using the already available signals in current defibrillators. TI measures the resistance of the thorax to current flow. It is calculated by passing an alternate current (usually 2–3 mA at 20–30 kHz) through the tissue, measuring the voltage drop, and calculating the impedance using the Ohm's law. TI is used to check if defibrillation pads are correctly attached to the patient and to adjust the energy of the defibrillation pulse.

Baseline TI is approximately 70–80 Ω in adults, but changes in tissue composition due to redistribution and movement of fluids cause fluctuations on the TI. For example, blood circulation and respiration (or ventilation) generate oscillations of different amplitudes in the TI. In addition, chest compressions during CPR cause a disturbance in the electrode-skin interface, inducing artifacts on the TI. With each compression, the TI fluctuates around the baseline impedance with amplitude varying from 0.15 Ω to several Ohms. Figure 8 shows a segment of the compression depth and the TI signals recorded during CPR. In the example, two series of 15 compressions were provided, with pauses for two ventilations in between. The oscillations in the TI signal reflect compressions and ventilations. In general, the waveform of the fluctuations induced by chest compressions is very variable between patients and even along each resuscitation episode.

The aim of this section is to explore the feasibility of using TI signal to provide feedback on the rate and depth of chest compressions.

Figure 8. Segment of compression depth and TI signals during CPR. Artifact induced by chest compressions and fluctuation induced by ventilations is clearly visible in the TI signal.

### 4.1. Use of the TI signal for chest compression quality assessment

Several researchers have investigated the use of TI signal for gathering information on the quality of chest compressions. Some studies focused on detecting the instants of the chest compressions in the TI signals to derive compression rate. Others have studied the relationship between compression depth and the amplitude of the TI fluctuations.

### 4.1.1. Chest compression rate

The commercial program Codestat (Physio-Control, Redmond, USA) incorporates an automated chest compression and ventilation detector based primarily on the analysis of the TI. The program annotates compression positions and derives the quality parameters compression rate and chest compression fraction (the percentage of time during which chest compressions are provided). Different filtering options allow the user to highlight chest compressions oscillations or ventilation oscillations. Other authors used the TI signal to automatically detect chest compressions in order to estimate the instantaneous compression rate [22]. They found a high correlation between the instantaneous rate computed from the TI and from the compression depth signal. The TI was used also to detect pauses in chest compressions [23] and could be used to measure chest compression fraction.

A comprehensive study that aimed to determine the feasibility of a generic algorithm for feedback on chest compression rate using the TI signal recorded through the defibrillation pads was recently published [24]. Out-of-hospital cardiac arrest episodes were collected equally from three different emergency services and different defibrillator models. The algorithm for computing compression rate was based on the spectral analysis of the TI signal. The gold standard was obtained from reference signals such as the force or the ECG. This approach was accurate under different device front ends and a wide range of conditions, proving the generality of the results. The availability of feedback on the rate of chest compressions could have a significant impact on the quality of CPR, especially in basic life-support emergency systems.

### 4.1.2. Chest compression depth

Regarding the relationship between chest compression depth and the amplitude of the fluctuations induced in the TI, contradictory results have been found in the literature. An experimental study conducted with swine reported higher amplitudes in the TI oscillations for higher compression depths [25]. Another study using porcine models reported high correlations between TI and systolic blood pressure, end-tidal CO2, cardiac output, and carotid flow [26]. Two clinical studies suggested the potential of TI to identify adequate chest compression depth in patients under cardiac arrest [27, 28]. However, none of those studies included any objective measurement of the actual compression depth; i.e., no gold standard was used to validate the hypothesis. In subsequent studies in which a reference compression depth was included, contradictory results were found, and limited details were provided on the methods and the data analyzed [29, 30]. Finally, a prospective, experimental study with swine by Zhang et al. [31] reported a high correlation between TI and both the compression depth and the coronary perfusion. They found significant differences in the TI fluctuation amplitude between adequate and shallow chest compressions, and a strong linear relationship between TI amplitude and compression depth. Authors concluded that changes in the TI had the potential to serve as an indicator of the quality of chest compressions. Nevertheless, they acknowledged that further research was required to extrapolate these conclusions to humans.

We present a study aimed to go further into this remaining question regarding TI signal and its application to provide feedback on chest compression quality: Is there a relationship between chest compression depth and TI in humans?

### 4.2. Estimation of chest compression depth from TI signal

The aim of this study was to analyze the relationship between TI fluctuations and compression depth during out-of-hospital cardiac arrest episodes. First, we analyzed the overall correlation between three morphologic features of the TI and the compression depth. Second, we evaluated the influence of the patient by computing this correlation independently for each patient. Third, we studied the influence of the rescuer, by isolating series of chest compressions corresponding to a unique rescuer-patient pair. Finally, we tried to replicate the experiments by Zhang et al., focusing on the correlation analysis with series of optimal and suboptimal chest compressions, and we assessed the discrimination power of the TI signals to distinguish between shallow and nonshallow chest compressions.

### 4.2.1. Data collection

4.1. Use of the TI signal for chest compression quality assessment

between compression depth and the amplitude of the TI fluctuations.

the quality of CPR, especially in basic life-support emergency systems.

4.1.1. Chest compression rate

88 Resuscitation Aspects

4.1.2. Chest compression depth

be used to measure chest compression fraction.

Several researchers have investigated the use of TI signal for gathering information on the quality of chest compressions. Some studies focused on detecting the instants of the chest compressions in the TI signals to derive compression rate. Others have studied the relationship

The commercial program Codestat (Physio-Control, Redmond, USA) incorporates an automated chest compression and ventilation detector based primarily on the analysis of the TI. The program annotates compression positions and derives the quality parameters compression rate and chest compression fraction (the percentage of time during which chest compressions are provided). Different filtering options allow the user to highlight chest compressions oscillations or ventilation oscillations. Other authors used the TI signal to automatically detect chest compressions in order to estimate the instantaneous compression rate [22]. They found a high correlation between the instantaneous rate computed from the TI and from the compression depth signal. The TI was used also to detect pauses in chest compressions [23] and could

A comprehensive study that aimed to determine the feasibility of a generic algorithm for feedback on chest compression rate using the TI signal recorded through the defibrillation pads was recently published [24]. Out-of-hospital cardiac arrest episodes were collected equally from three different emergency services and different defibrillator models. The algorithm for computing compression rate was based on the spectral analysis of the TI signal. The gold standard was obtained from reference signals such as the force or the ECG. This approach was accurate under different device front ends and a wide range of conditions, proving the generality of the results. The availability of feedback on the rate of chest compressions could have a significant impact on

Regarding the relationship between chest compression depth and the amplitude of the fluctuations induced in the TI, contradictory results have been found in the literature. An experimental study conducted with swine reported higher amplitudes in the TI oscillations for higher compression depths [25]. Another study using porcine models reported high correlations between TI and systolic blood pressure, end-tidal CO2, cardiac output, and carotid flow [26]. Two clinical studies suggested the potential of TI to identify adequate chest compression depth in patients under cardiac arrest [27, 28]. However, none of those studies included any objective measurement of the actual compression depth; i.e., no gold standard was used to validate the hypothesis. In subsequent studies in which a reference compression depth was included, contradictory results were found, and limited details were provided on the methods and the data analyzed [29, 30]. Finally, a prospective, experimental study with swine by Zhang et al. [31] reported a high correlation between TI and both the compression depth and the coronary perfusion. They found significant differences in the TI fluctuation amplitude between adequate and shallow chest compressions, and a strong linear relationship between TI amplitude and compression depth. Authors concluded that changes in the TI had the potential to The data set used in this study was collected by Tualatin Valley Fire & Rescue (TVF&R), a first response advanced life-support fire agency serving 11 incorporated cities in Oregon, USA. It comprised 623 out-of-hospital cardiac arrest episodes recorded during CPR. The compression depth and TI signals were available for 189 of the 623 episodes. We extracted 60 episodes containing both signals concurrently, with a minimum of 1000 chest compressions per episode. Only chest compressions included in series of at least 10 compressions were considered, yielding a total of 11,667,9 chest compressions. Then, we extracted intervals where the singlerescuer-single-patient pattern was guaranteed. Interruptions in compressions longer than 1.5 s were identified as a possible change of rescuer. We gathered 75 series of this type.

### 4.2.2. Signal processing and extraction of TI features

Compression depth signal was first processed to compute the maximum depth for each chest compression, Dmax. The instants when Dmax was achieved were computed using a negative peak detector with a static threshold of 15 mm. The cycle of each chest compression was then identified using these instants both in the compression depth and in the TI signals. This procedure is illustrated in Figure 9, where each cycle is delimited with vertical dotted lines. TI signal was band-pass filtered to remove baseline and fluctuations caused by ventilations and high-frequency noise. To characterize TI fluctuations, we defined three TI waveform features computed for each chest compression:


Figure 9. Two examples of the features extracted from the TI signal. The maximum depth is represented in the compression depth signal (top) and the TI features in the TI signal (bottom). Compression cycles are delimited by vertical dotted lines.

Figure 9 illustrates two examples with the extracted features depicted in the compression depth (top) and in the filtered TI signal (bottom). Panel (A) shows quite sinusoidal TI fluctuations, and panel (B) shows a more irregular TI waveform. This is why we computed area and curve length in addition to the peak-to-peak value of TI, as this single feature cannot discriminate between regular and irregular fluctuations. In order to smooth the values of the computed features, the average value of each parameter was computed every 5 s.

#### 4.2.3. Data analysis

The linear relationship between Dmax and the TI features was tested for the whole population, for each patient independently, and for series of compressions provided by a single rescuer on a single patient. Pearson's correlation coefficient r was computed for each analysis. Univariate linear regression was used to model the relationship between Dmax and the TI features.

In order to avoid potential variability introduced by the rescuer, we analyzed the relationship between Dmax and Zpp in a single-rescuer-single-patient pattern. Series with a minimum standard deviation of 7 mm in Dmax were considered. To avoid bias, a single series per patient was selected, the one with the highest standard deviation. A total of nine series were extracted. Univariate linear regression was used to predict Dmax using Zpp, and r coefficient was computed for each series and jointly for the whole set.

In order to replicate the procedure by Zhang et al. in their swine model [31], we selected series with optimal and suboptimal series of chest compressions. A series was suboptimal when at least 75% of the compressions were below 38 mm, and optimal when at least 75% of the compressions were above 50 mm. A total of 12 series (one per patient) were selected. They were jointly analyzed computing r and applying univariate linear regression.

Finally, we assessed the discrimination power of the three TI features to classify each 5-s window as shallow (below 38 mm) or nonshallow (above 43 mm) according to the criteria stated by 2005 resuscitation guidelines (valid at the time episodes were collected). We applied a multivariate logistic regression model for the classifier. We split the 60 episodes into a training (40) and a test set (20). The power of the classifier was evaluated in terms of the area under the curve (AUC), and of the sensitivity and specificity in the diagnosis of shallow chest compressions.

### 4.2.4. Results

Figure 9 illustrates two examples with the extracted features depicted in the compression depth (top) and in the filtered TI signal (bottom). Panel (A) shows quite sinusoidal TI fluctuations, and panel (B) shows a more irregular TI waveform. This is why we computed area and curve length in addition to the peak-to-peak value of TI, as this single feature cannot discriminate between regular and irregular fluctuations. In order to smooth the values of the com-

Figure 9. Two examples of the features extracted from the TI signal. The maximum depth is represented in the compression depth signal (top) and the TI features in the TI signal (bottom). Compression cycles are delimited by vertical dotted

depth (mm)

(A) (B)

*z*p[n] (

Ω)

0



1.0

0


*Z*pp*<sup>i</sup>*

*Ci*<sup>+</sup><sup>1</sup> *Ai*<sup>+</sup><sup>2</sup>

time (s)

0 1 2

The linear relationship between Dmax and the TI features was tested for the whole population, for each patient independently, and for series of compressions provided by a single rescuer on a single patient. Pearson's correlation coefficient r was computed for each analysis. Univariate

In order to avoid potential variability introduced by the rescuer, we analyzed the relationship between Dmax and Zpp in a single-rescuer-single-patient pattern. Series with a minimum standard deviation of 7 mm in Dmax were considered. To avoid bias, a single series per patient was selected, the one with the highest standard deviation. A total of nine series were extracted. Univariate linear regression was used to predict Dmax using Zpp, and r coefficient was com-

In order to replicate the procedure by Zhang et al. in their swine model [31], we selected series with optimal and suboptimal series of chest compressions. A series was suboptimal when at least 75% of the compressions were below 38 mm, and optimal when at least 75% of the

linear regression was used to model the relationship between Dmax and the TI features.

puted features, the average value of each parameter was computed every 5 s.


*Ci*<sup>+</sup><sup>1</sup> *Ai*<sup>+</sup><sup>2</sup>

time (s)

0 1 2

puted for each series and jointly for the whole set.

4.2.3. Data analysis

*D*max*<sup>i</sup>*

*Z*pp*<sup>i</sup>*

depth (mm)

90 Resuscitation Aspects

*z*p[n] (

lines.

Ω)

0


1.0

0


Figure 10 shows the scatterplots of Dmax against each of the TI features for the whole population and the model fitted in each case. In all cases, there was a high dispersion around the regression line. The value of r was 0.34, 0.36, and 0.37 for Zpp, A, and C, respectively. However,

Figure 10. Scatterplots of Dmax with respect to TI features for the whole population. For each scatterplot, the fitted regression line and the value of r are depicted.

the analysis within patients yielded a median (IQR) correlation coefficient r of 0.40 (0.24–0.66) for Zpp, 0.43 (0.26–0.66) for A, and 0.47 (0.25–0.68) for C.

For the nine series in which the single-patient-single-rescuer pattern was maintained, the individual analysis of each series yielded a median r of 0.81 (0.51–0.83). However, when all of them were considered jointly, r decreased to 0.47.

In the analysis parallel to the one conducted by Zhang et al., we considered the set of twelve optimal and suboptimal series. For the optimal group, Dmax was 57 (54–63) mm and Zpp was 3.0 (2.5–3.7) Ω. For the suboptimal group, Dmax was 32 (30–34) mm, and Zpp was 0.9 (0.6–1.5) Ω. We obtained a correlation coefficient of 0.87, quite similar to the 0.89 reported by Zhang et al.

Finally, when analyzing the power of each feature to classify 5-s windows as shallow or nonshallow, we found significant differences between groups, but a high overlap between distributions. The logistic regression classifier showed sensitivity, specificity, and AUC of 89%, 49%, and 0.8 for the test set.

### 4.2.5. Discussion

Our study included a set of out-of-hospital cardiac arrest episodes with a wide variety of patients and rescuers. The results obtained from the analysis of 14,424 values for each feature showed very low correlation with Dmax (r < 0.38 in any case). Prediction of chest compression depth with any of the TI features was highly unreliable. For instance, for any given Zpp value, the probability of error in the prediction of Dmax is high because of the wide range of corresponding Dmax values.

The variability of the results between patients was also high. Sex, chest size, body mass, and pads position have been reported to affect TI baseline, and TI fluctuations during ventilations are correlated with the thoracic fat and thoracic circumference. Our results showed also a great dispersion with respect to the regression line between Dmax and Zpp from one patient to another. Although, for some patients, little dispersion and high correlation values could be observed along the episode, different tendencies were also found within each episode, showing the influence of different rescuers. In these cases, a single regression model will hardly fit all the values.

With a single rescuer, the dispersion of each series decreased, and linearity between Dmax and Zpp increased notably. Nevertheless, interpatient factors such as chest/electrodes characteristics of the nine patients caused a low correlation when all the series were considered jointly. This emphasizes the inability to define a confident global linear fit.

Finally, we could replicate the high linearity observed between depth and TI amplitude reported by Zhang et al. in the animal model. We also found significant differences between the optimal and the suboptimal groups, but we also found that for a given value of Zpp, Dmax varied widely. For a proper interpretation of the apparent observed linearity, we should consider the limitations of the analysis. On the one hand, considering only optimal and suboptimal chest compressions shows a biased picture of human out-of-hospital CPR. When the complete range of compression depths is considered, the correlation coefficient drops to 0.34. On the other hand, the set of patients and rescuers was small (12 patients/12 rescuers in our study, 14 animals/2 rescuers in the study by Zhang et al.). When we included a greater variability (60 patients and 2 to 6 rescuers), higher dispersion was observed and correlation coefficient decreased substantially.

In summary, TI signal can be a feasible indicator for CPR quality parameters such as chest compression rate, chest compression fraction or chest compression pauses. Unfortunately, in this study, we proved that TI is unreliable to predict the key quality parameter of chest compression depth. Nevertheless, we further analyzed, from a practical perspective, the power to discriminate shallow from nonshallow chest compressions, in an effort to achieve a quality feedback method. We tried to discriminate chest compressions <38 mm from those >43 mm. Each TI feature showed different distributions between the two categories, but high overlap between them. The results of the logistic regression classifier allowed us to conclude that it is not possible to safely identify shallow chest compressions using the TI signal.

### 5. Conclusions

the analysis within patients yielded a median (IQR) correlation coefficient r of 0.40 (0.24–0.66)

For the nine series in which the single-patient-single-rescuer pattern was maintained, the individual analysis of each series yielded a median r of 0.81 (0.51–0.83). However, when all of

In the analysis parallel to the one conducted by Zhang et al., we considered the set of twelve optimal and suboptimal series. For the optimal group, Dmax was 57 (54–63) mm and Zpp was 3.0 (2.5–3.7) Ω. For the suboptimal group, Dmax was 32 (30–34) mm, and Zpp was 0.9 (0.6–1.5) Ω. We obtained a correlation coefficient of 0.87, quite similar to the 0.89 reported by Zhang

Finally, when analyzing the power of each feature to classify 5-s windows as shallow or nonshallow, we found significant differences between groups, but a high overlap between distributions. The logistic regression classifier showed sensitivity, specificity, and AUC of

Our study included a set of out-of-hospital cardiac arrest episodes with a wide variety of patients and rescuers. The results obtained from the analysis of 14,424 values for each feature showed very low correlation with Dmax (r < 0.38 in any case). Prediction of chest compression depth with any of the TI features was highly unreliable. For instance, for any given Zpp value, the probability of error in the prediction of Dmax is high because of the wide range of

The variability of the results between patients was also high. Sex, chest size, body mass, and pads position have been reported to affect TI baseline, and TI fluctuations during ventilations are correlated with the thoracic fat and thoracic circumference. Our results showed also a great dispersion with respect to the regression line between Dmax and Zpp from one patient to another. Although, for some patients, little dispersion and high correlation values could be observed along the episode, different tendencies were also found within each episode, showing the influence of different rescuers. In these cases, a single regression model will hardly fit

With a single rescuer, the dispersion of each series decreased, and linearity between Dmax and Zpp increased notably. Nevertheless, interpatient factors such as chest/electrodes characteristics of the nine patients caused a low correlation when all the series were considered jointly. This

Finally, we could replicate the high linearity observed between depth and TI amplitude reported by Zhang et al. in the animal model. We also found significant differences between the optimal and the suboptimal groups, but we also found that for a given value of Zpp, Dmax varied widely. For a proper interpretation of the apparent observed linearity, we should consider the limitations of the analysis. On the one hand, considering only optimal and suboptimal chest compressions shows a biased picture of human out-of-hospital CPR. When

emphasizes the inability to define a confident global linear fit.

for Zpp, 0.43 (0.26–0.66) for A, and 0.47 (0.25–0.68) for C.

them were considered jointly, r decreased to 0.47.

89%, 49%, and 0.8 for the test set.

corresponding Dmax values.

et al.

92 Resuscitation Aspects

4.2.5. Discussion

all the values.

During CPR, the quality of chest compressions is related to patient's survival. Feedback devices guide the rescuers toward target compression depth and rate, and contribute to increase the CPR quality. This chapter explored new alternatives to provide feedback on the quality of chest compressions during CPR. Two strategies were studied: the use of the chest acceleration, which can be acquired using an extra pad placed on the chest of the patient during CPR and the use of the transthoracic impedance (TI) signal, which is acquired by current defibrillators through defibrillation pads. Chest acceleration can be used to accurately compute chest compression rate and depth in a wide range of conditions. TI, in contrast, can be used to accurately compute chest compression rate, but not to identify too shallow chest compressions. The development of simpler feedback devices could contribute to their widespread use and to increase the CPR quality.

### Acknowledgements

This book chapter derives from the thesis work Feedback systems for the quality of chest compressions during cardiopulmonary resuscitation carried out by author Digna M. González-Otero, under the supervision of co-authors Jesus Ruiz and Sofía Ruiz de Gauna. Several parts of this work have been published in indexed journals or presented at international conferences.

This research received financial support from the Spanish Government through the project TEC2012-31144 and from the Basque Government through the grant no. BFI-2011-166 and through the project IT1087-16.

Authors thank all volunteers participating in the manikin study and the TVF&R emergency medical services providers for collecting the out-of-hospital cardiac arrest data.

### Author details

Digna M. González-Otero\*, Sofía Ruiz de Gauna, Jesus M. Ruiz, José Julio Gutiérrez, Purificación Saiz and Mikel Leturiondo

\*Address all correspondence to: dignamaria.gonzalez@ehu.eus

University of the Basque Country (UPV/EHU), Bilbao, Spain

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Author details

94 Resuscitation Aspects

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\*Address all correspondence to: dignamaria.gonzalez@ehu.eus

University of the Basque Country (UPV/EHU), Bilbao, Spain

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**Provisional chapter**
