**9. Cardiac arrest in special circumstances**

#### **9.1 Traumatic cardiac arrest**

The traumatic arrest is one of the etiologies of cardiac arrest with a very poor outcome [86–92]. To improve its outcome, there is a need to draw our attention to the possible reversible causes of traumatic cardiac arrest [93].

Recent data has clarified that traumatic cardiac arrest patients have no worse outcome than that of the medical causes of cardiac arrest [94]. Some of the reversible causes of cardiac arrest in traumatic patients are hypovolemia, tension pneumothorax, and cardiac tamponade.

#### *9.1.1 Hypovolemia and rapid fluid resuscitation*

In-depth analysis of traumatic cardiac arrest patients has demonstrated that the majority of the survivable traumatic cardiac arrest patients have pulseless electrical activity (PEA) [95]. This implies that the heart is beating, but the peripheral pulse is not palpable. It is often seen that this is a low output state rather than a true cardiac arrest. This is supported by the fact that such patients often have multiple wounds and suffer significant blood loss. Chest compressions are more effective in euvolemic patients as compared to suspected hypovolemic patients of traumatic cardiac arrest, rather they can worsen coronary perfusion [96]. Considering the etiology, the treatment algorithm must also be modified in these cases. Treatment must involve external compression to stop further loss, gaining access to wide-bore cannula, and initiate rapid transfusion of blood and blood products along with the attempts of CPR. In contrast to the traditional teaching, blood and blood products are preferred over the crystalloid transfusion [97, 98]. Although supportive evidence has demonstrated improved survival in patients receiving more fluid resuscitation (crystalloids) [99].

#### *9.1.2 Tension pneumothorax*

Tension pneumothorax may be suspected when there is decreased air entry even after checking the position of the endotracheal tube. It is one of the reversible causes of cardiac arrest, it is stated that chest compression should not delay the treatment of the reversible cause. It can either be achieved by immediate needle decompression or thoracotomy. In the case of positive pressure ventilation, thoracostomy is a preferred technique as it is more effective than needle decompression and less time-consuming that chest tube insertion [86]. Whereas, in the case of needle decompression, there can be technical difficulties like kinking, dislodgment, insufficient length of needle leading to insufficient decompression [100]. Decompression demonstrated the return of ROSC in these patients [101]. On the scene, decompression is recommended for all patients of traumatic cardiac arrest with tension pneumothorax [102].

#### *9.1.3 Cardiac tamponade*

Low energy penetrating wounds can cause myocardial injury leading to an accumulation of blood in pericardial space. Cardiac tamponade can be a cause of arrest in 10% of cardiac arrests in trauma. Cardiac tamponade needs to be evacuated immediately to achieve successful resuscitation post-CPR. Retrospective data collected from a military hospital has demonstrated survival as high as 21.5% in post-traumatic cardiac arrest patients post thoracotomy [95].

Ultrasound can help in timely diagnosis PEA, cardiac tamponade, tension pneumothorax, and even hypovolemia by IVC diameter [103].

#### **9.2 Cardiac arrest after cardiac surgery**

Cardiac arrests after cardiac surgeries are unique entities that need to be addressed uniquely. It usually takes place within the hospital facility which thereby increases the chances of early diagnosis. Timely resuscitation is possible in the presence of expertise with easy access to defibrillator or pacing facility, early CPR, and rapid sternotomy. About 8% of the cardiac surgery patients suffer from perioperative cardiac arrest, with a shockable rhythm in 30–50% and mechanical causes like cardiac tamponade or graft failure in 28% of the cases [104]. The incidence of different arrhythmias varies in different studies. A recent study reported the incidence of VF and pVT in 70%, asystole in 17%, and PEA in 13% of cardiac arrests [105].

During the cardiac arrest, various monitoring waveforms like arterial pressure, central venous pressure, and pulmonary artery pressure are non-pulsatile. If the ECG tracing reveals VF/ p VT, three stalked shocks must be delivered if available within 1 min. Brief CPR in patients shortly after cardiac surgery can induce lacerations and hemorrhage due to serrated sternal edges and projecting steel wires and hence not preferred [106, 107]. Numerous studies have demonstrated improved outcomes with early defibrillation for witnessed arrest [108, 109]. In the scenario of OHCA, single shock protocol is preferred but the same may not be applicable for witnessed IHCA and procedural settings. Subsequent shocks given within 1 min showed statistically significant survival benefits over the deferred second shock in VF/pVT [110]. Thus, considering the risks and benefits it is recommended to give three sequential shocks without intervening external cardiac massage in patients of VF/pVT if available within 1 min. A bolus of 300 mg intravenous amiodarone should be given via central line after failed defibrillation and CPR should be initiated [111]. Studies have demonstrated the advantage of internal cardiac massage as compared to external in establishing adequate cerebral and coronary perfusion (CPP) [112, 113]. Maximal CPP is a direct indicator of ROSC [114]. It is recommended to perform cardiac massage at the rate of 100–120 per minute with a target systolic pressure of at least 60 mm of Hg.

If the CPR is performed correctly, and still the target pressure is not achieved, it suggests a surgical problem like cardiac tamponade. PEA is commonly seen in cardiac tamponade or hemorrhage. Rapid sternotomy is the treatment of choice and once compression is released; internal massaging can be continued allowing initial stabilization while the patient is shifted back to the operating room. Direct visualization allows the diagnosis of the mechanical cause of the arrest and early intervention. Pottle and colleagues have demonstrated survival benefit when the

**13**

[104, 117].

*Cardiopulmonary Resuscitation: Recent Advances DOI: http://dx.doi.org/10.5772/intechopen.91866*

tation protocol for cardiac surgery patients [111].

the midclavicular line to decompress immediately.

ordered by an experienced clinician.

**9.3 Cardiac arrest in pregnancy**

over external [115].

witnessed cardiac arrest.

sternotomy was done within 5 min of arrest supporting internal cardiac massage

In asystole, epicardial pacing (DOO mode, maximal atrial, and ventricular output, 80–100/min) should be initiated within 1 min if available before CPR and resternotomy otherwise transcutaneous pacing may be used. Transcutaneous pacing involves delivery of electrical impulses through the patient chest by applying pads on thoracic wall stimulating the heart. It is mainly indicated during hemodynamic instability due to refractory bradycardia, sick sinus syndrome, and asystolic cardiac arrest. Transcutaneous pacing during cardiac arrest is more successful in

In cases of PEA, the pacemaker should be temporarily turned off to check the rhythm as it can mask the VF. Atropine is not recommended as a part of the resusci-

Epinephrine is not routinely recommended as a part of the resuscitation protocol in post-cardiac surgery patients. Studies have demonstrated it can cause more harm than help. Although successful in restoring the circulation, it can raise the blood pressure to such high levels that can damage the anastomosis sutures leading to hemorrhage. Many research trials have shown the success of epinephrine in starting the initial rhythm but poor overall survival rates and increase brain damage [116]. If required, it can be used in impending arrest at a lower dose (50–300 mcg) only if

Usually, the post-cardiac surgical patients are intubated, there is a risk of endobronchial intubation, pneumothorax, and hemothorax. Management of airway and ventilation involves increasing the FiO2 to 100% and excluding the positive end expiration pressure, checking the position of the endotracheal tube and excluding tension pneumothorax or hemothorax [39]. In case of tension pneumothorax or hemothorax, a wide-bore needle should be inserted in second intercostal's space,

Cardiac arrests in post-cardiac surgery patients is a unique entity that mandates necessary changes in conventional resuscitation protocols to improve their outcome

Cardiac arrest in pregnant patients is dealt with as a separate entity. Recent data has shown most etiology due to reversible cause with a high survival rate of >50% [118]. This challenges the historical concept of poor survival and futility of resuscitation [119]. This special group of young people responds well to resuscitation

First and foremost is the need to identify common causes of arrest in pregnant patients, which must be reversed while resuscitating the patients to improve the chances of ROSC. Anesthetic complications like inadvertent spinal injection and airway complications are the most common cause followed by hemorrhage (intrapartum or postpartum) [120]. Other causes can be attributed to cardiovascular causes like peripartum cardiomyopathy, heart failure owing to pre-existing valve

Resuscitation in pregnant patients requires sequential coordinated simultaneous interventions. A multidisciplinary team of health care providers including an obstetrician, neonatologist, anesthesiologist, intensivist, a cardiologist, and cardiovascular surgeon should be involved during resuscitation. High-quality chest compressions of 5–6 cm depth at the rate of 100–120 per minute at the mid sternal position with adequate recoil will provide a good circulatory function. The gravid uterus can lead to aortocaval compression, impairing venous return. Tilting

efforts, encouraging us to streamline resuscitation guidelines [118].

disease, drugs errors, anaphylaxis, and thromboembolic complications.

*Cardiopulmonary Resuscitation: Recent Advances DOI: http://dx.doi.org/10.5772/intechopen.91866*

*Sudden Cardiac Death*

with tension pneumothorax [102].

**9.2 Cardiac arrest after cardiac surgery**

systolic pressure of at least 60 mm of Hg.

*9.1.3 Cardiac tamponade*

insufficient length of needle leading to insufficient decompression [100]. Decompression demonstrated the return of ROSC in these patients [101]. On the scene, decompression is recommended for all patients of traumatic cardiac arrest

Low energy penetrating wounds can cause myocardial injury leading to an accumulation of blood in pericardial space. Cardiac tamponade can be a cause of arrest in 10% of cardiac arrests in trauma. Cardiac tamponade needs to be evacuated immediately to achieve successful resuscitation post-CPR. Retrospective data collected from a military hospital has demonstrated survival as high as 21.5% in

Ultrasound can help in timely diagnosis PEA, cardiac tamponade, tension

Cardiac arrests after cardiac surgeries are unique entities that need to be addressed uniquely. It usually takes place within the hospital facility which thereby increases the chances of early diagnosis. Timely resuscitation is possible in the presence of expertise with easy access to defibrillator or pacing facility, early CPR, and rapid sternotomy. About 8% of the cardiac surgery patients suffer from perioperative cardiac arrest, with a shockable rhythm in 30–50% and mechanical causes like cardiac tamponade or graft failure in 28% of the cases [104]. The incidence of different arrhythmias varies in different studies. A recent study reported the incidence of VF and pVT in 70%, asystole in 17%, and PEA in 13% of cardiac arrests [105]. During the cardiac arrest, various monitoring waveforms like arterial pressure, central venous pressure, and pulmonary artery pressure are non-pulsatile. If the ECG tracing reveals VF/ p VT, three stalked shocks must be delivered if available within 1 min. Brief CPR in patients shortly after cardiac surgery can induce lacerations and hemorrhage due to serrated sternal edges and projecting steel wires and hence not preferred [106, 107]. Numerous studies have demonstrated improved outcomes with early defibrillation for witnessed arrest [108, 109]. In the scenario of OHCA, single shock protocol is preferred but the same may not be applicable for witnessed IHCA and procedural settings. Subsequent shocks given within 1 min showed statistically significant survival benefits over the deferred second shock in VF/pVT [110]. Thus, considering the risks and benefits it is recommended to give three sequential shocks without intervening external cardiac massage in patients of VF/pVT if available within 1 min. A bolus of 300 mg intravenous amiodarone should be given via central line after failed defibrillation and CPR should be initiated [111]. Studies have demonstrated the advantage of internal cardiac massage as compared to external in establishing adequate cerebral and coronary perfusion (CPP) [112, 113]. Maximal CPP is a direct indicator of ROSC [114]. It is recommended to perform cardiac massage at the rate of 100–120 per minute with a target

If the CPR is performed correctly, and still the target pressure is not achieved, it suggests a surgical problem like cardiac tamponade. PEA is commonly seen in cardiac tamponade or hemorrhage. Rapid sternotomy is the treatment of choice and once compression is released; internal massaging can be continued allowing initial stabilization while the patient is shifted back to the operating room. Direct visualization allows the diagnosis of the mechanical cause of the arrest and early intervention. Pottle and colleagues have demonstrated survival benefit when the

post-traumatic cardiac arrest patients post thoracotomy [95].

pneumothorax, and even hypovolemia by IVC diameter [103].

**12**

sternotomy was done within 5 min of arrest supporting internal cardiac massage over external [115].

In asystole, epicardial pacing (DOO mode, maximal atrial, and ventricular output, 80–100/min) should be initiated within 1 min if available before CPR and resternotomy otherwise transcutaneous pacing may be used. Transcutaneous pacing involves delivery of electrical impulses through the patient chest by applying pads on thoracic wall stimulating the heart. It is mainly indicated during hemodynamic instability due to refractory bradycardia, sick sinus syndrome, and asystolic cardiac arrest. Transcutaneous pacing during cardiac arrest is more successful in witnessed cardiac arrest.

In cases of PEA, the pacemaker should be temporarily turned off to check the rhythm as it can mask the VF. Atropine is not recommended as a part of the resuscitation protocol for cardiac surgery patients [111].

Epinephrine is not routinely recommended as a part of the resuscitation protocol in post-cardiac surgery patients. Studies have demonstrated it can cause more harm than help. Although successful in restoring the circulation, it can raise the blood pressure to such high levels that can damage the anastomosis sutures leading to hemorrhage. Many research trials have shown the success of epinephrine in starting the initial rhythm but poor overall survival rates and increase brain damage [116]. If required, it can be used in impending arrest at a lower dose (50–300 mcg) only if ordered by an experienced clinician.

Usually, the post-cardiac surgical patients are intubated, there is a risk of endobronchial intubation, pneumothorax, and hemothorax. Management of airway and ventilation involves increasing the FiO2 to 100% and excluding the positive end expiration pressure, checking the position of the endotracheal tube and excluding tension pneumothorax or hemothorax [39]. In case of tension pneumothorax or hemothorax, a wide-bore needle should be inserted in second intercostal's space, the midclavicular line to decompress immediately.

Cardiac arrests in post-cardiac surgery patients is a unique entity that mandates necessary changes in conventional resuscitation protocols to improve their outcome [104, 117].

#### **9.3 Cardiac arrest in pregnancy**

Cardiac arrest in pregnant patients is dealt with as a separate entity. Recent data has shown most etiology due to reversible cause with a high survival rate of >50% [118]. This challenges the historical concept of poor survival and futility of resuscitation [119]. This special group of young people responds well to resuscitation efforts, encouraging us to streamline resuscitation guidelines [118].

First and foremost is the need to identify common causes of arrest in pregnant patients, which must be reversed while resuscitating the patients to improve the chances of ROSC. Anesthetic complications like inadvertent spinal injection and airway complications are the most common cause followed by hemorrhage (intrapartum or postpartum) [120]. Other causes can be attributed to cardiovascular causes like peripartum cardiomyopathy, heart failure owing to pre-existing valve disease, drugs errors, anaphylaxis, and thromboembolic complications.

Resuscitation in pregnant patients requires sequential coordinated simultaneous interventions. A multidisciplinary team of health care providers including an obstetrician, neonatologist, anesthesiologist, intensivist, a cardiologist, and cardiovascular surgeon should be involved during resuscitation. High-quality chest compressions of 5–6 cm depth at the rate of 100–120 per minute at the mid sternal position with adequate recoil will provide a good circulatory function. The gravid uterus can lead to aortocaval compression, impairing venous return. Tilting the patient to a lateral position relieves the compression but does not allow chest compression. A study on mannequin demonstrated that a tilt of 27° was enough during chest compression to stop mannequin from falling but with the limitation of achieving 80% of force for CCs as compared to supine position [121]. A virtual gastroscopy demonstrated lateral displacement of the heart on lateral tilt offsetting the pumping action of chest compression [122]. A study utilized MRI to demonstrate compression of inferior vena cava and partial release on the lateral tilt of 30° in pregnant patients as compared to non-pregnant patients [123]. Considering this, manual displacement of the uterus can relieve the compression without affecting the vector force during chest compression, although delivery of the fetus is the ultimate and most comprehensive way of relieving the aortocaval compression. CPR is performed at a ratio of 30 compressions and 2 breaths. Oxygenation is the ultimate goal, the airway must be secured as soon as possible. It prevents aspiration and provides treatment for the respiratory cause of arrest. Considering the physiological changes of pregnancy and experienced laryngoscopist must perform intubation with an endotracheal tube of a smaller diameter. Recent studies have shown no advantage of the advanced airway during CPR in-hospital resuscitation, but this may not hold in pregnant patients keeping in view the physiological changes of pregnancy [124].

Rhythm analysis, defibrillation, and drugs used are similar to non-pregnant patients. Intravenous cannulation must be established above the diaphragm, to prevent the cut off of drugs due to gravid uterus causing aortocaval compression.

It is reasonable to perform perimortem caesarian delivery within 5 min of resuscitation maternal cardiac arrest. It maximizes the neonatal outcome as well as improves the maternal outcome [118].
