**5. Intraoperative management of anesthesia**

#### **5.1. Induction of anesthesia**

The anesthesia station is the working area of the anesthetist. Before the surgical procedure, all drugs and equipments required for anesthetic administration should be checked. The neonate should be properly monitored and placed on a forced-air warming mattress before the induction of anesthesia. A safe intravenous access should be established for drug use and fluid therapy. The use of a topical anesthetic such as EMLA cream facilitates awake placement of intravenous cannula [30].

In addition to routine monitoring, direct observation of the neonate is also an important monitoring method. This observation allows the anesthetist to recognize early signs of certain clinic situations (such as cyanosis and pallor).

difficult pediatric airway, advanced airway devices (such as Glidescope, Airtraq) which allow

The anesthesia device must be pre-checked before surgical procedure and anesthesia practice. It is essential that the anesthesia ventilator has the ability to provide neonatal compliance, small tidal volume *(*usually in pressure controlled ventilator mode) and positive end-expiratory pressure [24]. In recent years, new generation anesthesia machines have been developed which is able to small tidal volumes [28] and to provide the ability to ventilate using pressure

Heart rate-electrocardiography, non-invasive blood pressure, pulse oximetry, and tempera-

In neonates whom more risky for surgical procedures, in major surgical procedures and a special circumstances (such as congenital cardiac surgery, oesophageal atresia, congenital diaphragmatic hernia, expected ventilation-perfusion anomalies, hemodynamic changes, and acid-base imbalance), invasive arterial blood pressure and central venous pressure should be

Two oxygen saturation probes (the right arm probe – pre ductal, the leg probe - post ductal) must be plugged. This approach may provide the diagnosis as, with reverting to transitional

In last three decades, continuous monitoring of respiratory gases (inspiratory oxygen and expiratory end-tidal carbon dioxide and monitoring of gas flows) and continuous use of ven-

The precordial oesophageal stethoscope is a traditional and still valid method of monitoring the newborn. With this method, changes in heart rate and respiratory parameters can be

The anesthesia station is the working area of the anesthetist. Before the surgical procedure, all drugs and equipments required for anesthetic administration should be checked. The neonate should be properly monitored and placed on a forced-air warming mattress before the induction of anesthesia. A safe intravenous access should be established for drug use and fluid therapy. The use of a topical anesthetic such as EMLA cream facilitates awake placement of

circulation and is important to evaluate possible PDA mediated shunt development.

tilator disconnection devices are observed routinely in most anesthesia clinic [27].

ture monitorizations are sufficient for basic monitorizations in a healthy newborn.

indirect visualization of the larynx should be available [27].

*4.3.2. Anesthesia devices*

134 Selected Topics in Neonatal Care

support ventilation (PSV) [29].

*4.3.3. Monitoring*

monitored.

identified in early phase.

**5.1. Induction of anesthesia**

intravenous cannula [30].

**5. Intraoperative management of anesthesia**

Inhalation agents or intravenous anesthetics may be used for induction of anesthesia. Although depending on the choice of anesthetist, induction with inhalation anesthetics is a more preferred method. One of the characteristics of the newborns that are different from older children and adults is that they have relatively high alveolar ventilation but low functional residual capacity [6, 14, 24]. This higher minute ventilation to FRC ratio with relatively higher blood flow to vessel rich organs contributes to a rapid increase in alveolar anesthetic concentration*.* These features enable rapid induction and rapid recovery in general anesthesia [6].

Inhalational induction has the advantage of protection of spontaneous ventilation (especially, important in neonates with potentially difficult airway).

With the advantages we have mentioned above, volatile anesthetics cause dose dependent cardiac and respiratory depressant effect in neonates. These effects can result bradycardia, hypotension and postoperative apnea. This hypotensive effect is also more pronounced in neonates and preterms with cardiovascular instability than older children.

Also, immature airway and respiratory system may cause airway obstruction in mask ventilation during induction phase. Laryngospasm is a frequent occurrence in neonatal anesthesia in this period [31] and if it is intervened early is usually easy to manage. However, laryngospasm, hypoventilation, hypoxia are among the causes of apnea during induction (especially in cases of late notice) [32].

In short surgical procedures, mask ventilation or laryngeal mask airway may be suitable to support respiration. However, endotracheal intubation is frequently performed in patients with emergency surgical procedures, long and major surgical interventions, conditions that requiring muscle relaxation and aspiration risk.

In situation that where inhalation anesthetics are contraindicated or not preferred, intravenous anesthetics may be used to induce and maintain anesthesia.

As we have already mentioned, total body water and extracellular fluid are increased in neonates [16]. These different fluid component affect volumes of distribution of intravenous anesthetic drugs (this means increasing the volume of distribution, especially for water-soluble drugs).

In addition, due to the immaturity of hepatic functions, duration of action will be prolonged in neonates if the drug depends on hepatic metabolism [6].

Muscle relaxant may be required for some neonatal surgical procedures. However, due to immaturity of the neuromuscular junction, neonates have an increased sensitivity to the effects of nondepolarizing neuromuscular blocking drugs [33]. For this reason, prolonged effects may occur at additional doses.

#### **5.2. Intraoperative period**

Balanced general anesthesia management is usually achieved by inhalation anesthesia supplemented with different class and wide range of drugs and/or muscle relaxants and regional techniques or achieved by total intravenous anesthesia.

However, in some situations (such as in major surgical procedures, urgent surgery, full stom-

Neonatal Care for Anesthesiologists http://dx.doi.org/10.5772/intechopen.71952 137

In these patients, in these patients there are many factors that determine postoperative extu-

In major surgeries, (such as NEC, oesophageal atresia, diaphragmatic hernia) endotracheal intubation safer for these neonatal patients. In these neonates usually require elective postop-

Estuation period is a critical as intubation. Likewise, it requires to be careful and attentive. It should be take care with regard to residual neuromuscular block and the neuromuscular blocker drugs should be reversed. In extubation period, we may encounter with side effects such as bradycardia, hypoxia, bronchospasm, which can be seen in induction of anesthesia. Intubation equipments and drugs should be available in the anesthesia theater for immediate

Post-conceptional age (PCA) is important factor in ex-premature babies, for day case surgical procedures. Most ex-premature babies are suitable for day case surgical procedures at greater than 60 weeks post-conceptional age (PCA). Prior to 60 weeks PCA, especially in premature infants less than 44 weeks PCA, postoperative apnea risk increased. In these neonates is recommended postoperative saturation and apnea monitoring in postoperative 24 hours period. Pain in neonatal patients has for many years been ignored. However, the theory that new-

Recent studies have shown that neuroanatomical and neuroendocrine systems of premature

Untreated pain causes restlessness, increased oxygen consumption, ventilation/perfusion deficiency, and reduced food intake in early period of neonatal life. Long-term effects are learning disability and developmental retardation. Surgical trauma causes pain and a hormonal stress response that is directly related to the severity and urgency of surgery. Opioids (such as fentanyl, ultra-short acting remifentanil or traditional longer acting morphine) reduce the stress response and catecholamine release in response to painful stimuli. In addition, opioids provide effective pain control so decrease the pulmonary vasoconstrictor responses to

In recent years, intravenous paracetamol has begun to be used in the treatment protocol of

One of the most interesting topics in the last 20 years is the general anesthetic effect on the

**6. General anesthesia and developing brain. A special highlight for** 

ach, etc.) endotracheal intubation must be done to secure the airway.

erative mechanical ventilator support in early postoperative period in NICU.

borns do not feel pain has become a subject that has lost its validity nowadays.

newborns are sufficient for the transmission and perception of pain [37].

bation (including surgical conditions).

intervention.

painful stimuli in NICU.

**neonatal anesthesia**

developing brain and neurocognitive functions.

pain in neonates [38].

Barbiturates, opioids, propofol, ketamine listed among these intravenous drugs [14]. Longacting agents such as morphine should be avoided especially in day-case surgery or procedures and postoperative apnea risk should be kept in mind.

In neonatal patients, reduced hepatic glycogen stores, inadequate muscle glycogen reserve and gluconeogenesis enzyme activity require close monitoring of blood glucose concentration [34].

Intravenous glucose infusion may be required to maintain normoglycemia (serum glucose concentration of 40–90 mg dL [1, 24].

All maintenance fluids and blood products used intraoperatively must be warmed before use. Intravenous fluids should be titrated with an infusion pump or a fluid-adjusted burette to avoid excessive fluid loading and to give a controlled fluid.

Following the first few days of baby's life, in all newborns of gestational age, adequate intake of sodium is essential for continued normal developmental activity [1]. In full term neonates, it is not usually necessary to add sodium in maintenance fluids in the first 24 hours of life. However, sodium is added to the maintenance fluids after the second day to replace the sodium losses from the renal and gastrointestinal tract [35]. Also, non-hypotonic, dextrosecontaining fluids for sodium replacement may also be used. But, hypotonic fluids should be avoided. These fluids are most common cause of potentially lethal postoperative hyponatremia [35, 36].

Intraoperative fluid requirement should also be met, depending on pre-existing fluid deficits, quality and duration of operation, and the extent of blood loss.

It should not be allowed hypothermia during the intraoperative period. Hypothermia may cause stress in the newborn, leading to postoperative respiratory insufficiency and ventilatory support [10]. On the other hand, the only stressor factor that to avoid in newborns is not hypothermia. Many stress factors (such as hypotension episodes, hypoxia, hypercapnia, acidosis, anemia) can occur during intraoperative period. These factors leads increase PVR and can cause return of the transitional circulation [Ivanova-24]. Different therapeutic maneuvers such as hyperventilation, deepening anesthesia, increased inspired oxygen, and volume expansion may also help in treatment [10].

#### **5.3. Postoperative period and pain practices in neonate**

Many neonates undergoing day-case surgery can be anesthetized using mask ventilation and/or LMA by continuing spontaneous breathing without the use of muscle relaxants and intubation.

However, in some situations (such as in major surgical procedures, urgent surgery, full stomach, etc.) endotracheal intubation must be done to secure the airway.

**5.2. Intraoperative period**

136 Selected Topics in Neonatal Care

concentration of 40–90 mg dL [1, 24].

tion [34].

mia [35, 36].

intubation.

techniques or achieved by total intravenous anesthesia.

dures and postoperative apnea risk should be kept in mind.

to avoid excessive fluid loading and to give a controlled fluid.

quality and duration of operation, and the extent of blood loss.

expansion may also help in treatment [10].

**5.3. Postoperative period and pain practices in neonate**

Balanced general anesthesia management is usually achieved by inhalation anesthesia supplemented with different class and wide range of drugs and/or muscle relaxants and regional

Barbiturates, opioids, propofol, ketamine listed among these intravenous drugs [14]. Longacting agents such as morphine should be avoided especially in day-case surgery or proce-

In neonatal patients, reduced hepatic glycogen stores, inadequate muscle glycogen reserve and gluconeogenesis enzyme activity require close monitoring of blood glucose concentra-

Intravenous glucose infusion may be required to maintain normoglycemia (serum glucose

All maintenance fluids and blood products used intraoperatively must be warmed before use. Intravenous fluids should be titrated with an infusion pump or a fluid-adjusted burette

Following the first few days of baby's life, in all newborns of gestational age, adequate intake of sodium is essential for continued normal developmental activity [1]. In full term neonates, it is not usually necessary to add sodium in maintenance fluids in the first 24 hours of life. However, sodium is added to the maintenance fluids after the second day to replace the sodium losses from the renal and gastrointestinal tract [35]. Also, non-hypotonic, dextrosecontaining fluids for sodium replacement may also be used. But, hypotonic fluids should be avoided. These fluids are most common cause of potentially lethal postoperative hyponatre-

Intraoperative fluid requirement should also be met, depending on pre-existing fluid deficits,

It should not be allowed hypothermia during the intraoperative period. Hypothermia may cause stress in the newborn, leading to postoperative respiratory insufficiency and ventilatory support [10]. On the other hand, the only stressor factor that to avoid in newborns is not hypothermia. Many stress factors (such as hypotension episodes, hypoxia, hypercapnia, acidosis, anemia) can occur during intraoperative period. These factors leads increase PVR and can cause return of the transitional circulation [Ivanova-24]. Different therapeutic maneuvers such as hyperventilation, deepening anesthesia, increased inspired oxygen, and volume

Many neonates undergoing day-case surgery can be anesthetized using mask ventilation and/or LMA by continuing spontaneous breathing without the use of muscle relaxants and In these patients, in these patients there are many factors that determine postoperative extubation (including surgical conditions).

In major surgeries, (such as NEC, oesophageal atresia, diaphragmatic hernia) endotracheal intubation safer for these neonatal patients. In these neonates usually require elective postoperative mechanical ventilator support in early postoperative period in NICU.

Estuation period is a critical as intubation. Likewise, it requires to be careful and attentive.

It should be take care with regard to residual neuromuscular block and the neuromuscular blocker drugs should be reversed. In extubation period, we may encounter with side effects such as bradycardia, hypoxia, bronchospasm, which can be seen in induction of anesthesia. Intubation equipments and drugs should be available in the anesthesia theater for immediate intervention.

Post-conceptional age (PCA) is important factor in ex-premature babies, for day case surgical procedures. Most ex-premature babies are suitable for day case surgical procedures at greater than 60 weeks post-conceptional age (PCA). Prior to 60 weeks PCA, especially in premature infants less than 44 weeks PCA, postoperative apnea risk increased. In these neonates is recommended postoperative saturation and apnea monitoring in postoperative 24 hours period.

Pain in neonatal patients has for many years been ignored. However, the theory that newborns do not feel pain has become a subject that has lost its validity nowadays.

Recent studies have shown that neuroanatomical and neuroendocrine systems of premature newborns are sufficient for the transmission and perception of pain [37].

Untreated pain causes restlessness, increased oxygen consumption, ventilation/perfusion deficiency, and reduced food intake in early period of neonatal life. Long-term effects are learning disability and developmental retardation. Surgical trauma causes pain and a hormonal stress response that is directly related to the severity and urgency of surgery. Opioids (such as fentanyl, ultra-short acting remifentanil or traditional longer acting morphine) reduce the stress response and catecholamine release in response to painful stimuli. In addition, opioids provide effective pain control so decrease the pulmonary vasoconstrictor responses to painful stimuli in NICU.

In recent years, intravenous paracetamol has begun to be used in the treatment protocol of pain in neonates [38].
