Anesthetic Management Challenges in Pediatric Patients (Cont)

Ventilation strategies for infants and children are also important to tailor to each patient as there is greater risk for barotrauma and atelectrauma. The closing capacity of an infant’s lungs may be higher than functional residual capacity, making them prone to atelectasis and desaturation. Ventilation should be monitored continuously using end tidal CO2 monitoring intraoperatively as well as chest-rise and auscultation in the perioperative phases. In children at increased risk of apnea, a portable oxygen saturation monitor can be particularly useful during transport between care areas.

Induction is a very critical phase which can be approached in various ways, but may be dictated by the patient’s age, anxiety level, aspiration risk, or airway anatomy. Infants, toddlers, young children, and adolescents each require slightly different approaches to induction, depending on presence of peripheral access, level of anxiety, willingness to cooperate with mask induction, and reaction to the smell of the mask and sevoflurane. In some instances, nitrous oxide is used to “stun” the patient prior to use of sevoflurane to prevent the need for forceful restraint on induction. In general, children have a higher volume of distribution and thus require increased doses of intravenous anesthetic to achieve induction of anesthesia (the same is true for neuromuscular blockade). Inhalational induction is commonly used unless there is a concerning component to the patient’s status such as a difficult airway or full stomach, in which case rapid sequence intubation is indicated and a pre-induction IV must be placed. Premedication with midazolam or parental presence can be very effective in preventing an uncontrolled induction that may require forceful restraint of the child’s limbs and head.2 Such an event can be particularly harmful in patients with a preexisting injury or congenital malformation. The audiovisual environment of the operating room at time of induction must also be managed. Parents, if available, should be readily visible to the child, the OR should be quiet, and nursing staff should not be busy moving in the background. All available staff should be attentive and prepared to assist if needed during this critical phase. A pre-induction checklist is useful to prevent the need to search or ask for equipment during induction. Young children are at increased risk of laryngospasm if depth of anesthesia is lost due to forceful or interrupted mask induction.5 Thus, succinylcholine 3mg/kg with an IM needle should be readily available and the provider should already have the dose required in mind prior to induction. The use of succinylcholine must take into account the possibility of an undiagnosed muscular dystrophy in infants, which will present as hyperkalemia, rhabdomyolysis, and possibly renal dysfunction perioperatively. Finally, inhaled induction poses a risk of hypotension if large doses of volatile anesthetic are rapidly delivered to the point of causing bradycardia. This is due to the pediatric heart’s lack of dynamic compliance and its dependence on preload and heart rate for maintenance of cardiac output.

Maintenance of anesthesia in children has its own unique set of considerations. Again, there is a higher volume of distribution, shorter half-life, and quicker clearance for many of the commonly used IV anesthetics; thus their weight-based dose requirements are often higher. The minimum alveolar concentration (MAC) required for general anesthesia is also higher in children, peaking in infants up to around six months old and decreasing thereafter. Propofol, for example, requires administration of twice the adult infusion rate for maintenance of a total intravenous anesthetic and at least 50% increase in bolus doses for induction. Regarding neuromuscular blockade, neonates are actually more sensitive to paralysis and while the required induction dose may be relatively higher, the maintenance dose should be decreased. Children have higher incidence of postoperative nausea and vomiting (PONV) as well as emergence delirium; this must be considered and planned for preoperatively in order to prevent postoperative complications. In fact, children who experience preoperative anxiety are 3.5 times more likely to exhibit negative behavior postoperatively.2 Medications such as ondansetron and dexmedetomidine are useful for prophylaxis of PONV and emergence delirium respectively but must be dosed and timed appropriately for optimum effect. Temperature management must also be conducted aggressively It begins preoperatively with warming of the entire OR suite, and includes the use of forced air warmers and under-body blankets placed appropriately to avoid thermal injury. Pediatric patients are more prone to heat loss in the perioperative period due to their relatively larger head and higher surface area to mass ratio but are also more vulnerable to skin burns if warming devices are placed too close to the skin.

Emergence and extubation are just as critical as induction and intubation, given a child’s predisposition to PRAEs. The primary goal during this phase is to ensure adequate spontaneous oxygenation and ventilation, avoid laryngospasm, and to remove the airway either before or after Stage II, as this excitatory period is when children are most prone to PRAEs.3 Choosing between awake and deep extubation can be challenging in complex cases but is typically guided by patient factors such as: type of surgery, presence of difficult/airway, risk of aspiration or obstruction, risk of hematoma or damage to surgical closure with coughing, and risk of bronchospasm. For surgeries about the airway and neck, deep extubation is preferred to avoid hematoma formation which itself can completely obstruct the pediatric airway. If the airway is tenuous for any reason, awake extubation is preferred as this minimizes the potential for obstruction during emergence. Prior to deep extubation, adequate spontaneous ventilation, reversal of paralysis, and depth of anesthesia >1 MAC must be confirmed. Oropharyngeal and/or orogastric suctioning and manipulation of the airway within the trachea are commonly performed to remove any potentially stimulating secretions and assess patient reaction to mucosal stimulation. For awake extubation, confirmation of adequate spontaneous ventilation, reversal of paralysis, and observation for conjugate gaze and grimacing with suctioning should be performed to confirm recovery from anesthesia. Should laryngospasm occur in either setting, delivery of 100% oxygen with positive pressure ventilation via a mask with a tight seal will break mild laryngospasm; however more severe episodes may require increasing the depth of anesthesia with propofol or paralysis with succinylcholine. Thereafter, the patient should be supported with mask ventilation and/or intubation.

In planning the setting of surgery and postoperative care for children, the risk of postoperative apnea must be considered. Those patients with a history of obstructive sleep apnea or prematurity, and infants less than <44 weeks post-menstrual age are at increased risk of this complication and should be strongly considered for postoperative admission.4,8

In summary, pediatric anesthesiology is a challenging yet rewarding field that incorporates much of what providers have learned from their adult patients, but also requires the addition of several special considerations and a thorough understanding of pediatric anatomy, physiology, and pharmacokinetics. Some of the challenges seen in caring for adult patients, such as preoperative anxiety and adverse respiratory events, are more commonly seen in children and must be anticipated. Every aspect of the anesthesiologist’s approach to a case, from preoperative evaluation to extubation and recovery must be modified to the unique needs and constraints presented by children as they traverse the stages of their development. Success or failure depends heavily on how effective one is at recognizing and either preventing or diagnosing and treating these common anesthetic challenges and complications.

1. Apfelbaum, Caplan, Connis, Epstein, Nickinovich, Warner. Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: Application to healthy patients undergoing elective procedures: An updated report by the american society of anesthesiologists task force on preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration. Anesthesiology. 2011;114(3):495-511. doi: 10.1097/ALN.0b013e3181fcbfd9.

2. Banchs RJ, MD, Lerman, Jerrold, MD, FRCPC, FANZCA. Preoperative anxiety management, emergence delirium, and postoperative behavior. Anesthesiology Clinics. 2014;32(1):1-23. doi: 10.1016/j.anclin.2013.10.011.

3. Butz SF. Pediatric ambulatory anesthesia challenges. Anesthesiol Clin. 2019;37(2):289-300. Accessed Nov 3, 2019. doi: 10.1016/j.anclin.2019.01.002.

4. Coté CJ, Kelly DH. Postoperative apnea in a full-term infant with a demonstrable respiratory pattern abnormality. Anesthesiology. 1990;72(3):559-561. Accessed Nov 4, 2019. doi: 10.1097/00000542-199003000-00027.

5. De Francisci G, Papasidero AE, Spinazzola G, et al. Update on complications in pediatric anesthesia. Pediatric reports. 2013;5(1):e2. doi: 10.4081/pr.2013.e2.

6. Fortier MA, Kain ZN. Treating perioperative anxiety and pain in children: A tailored and innovative approach. Paediatr Anaesth. 2015;25(1):27-35. Accessed Nov 3, 2019. doi: 10.1111/pan.12546.

7. Gálvez JA, Acquah S, Ahumada L, et al. Hypoxemia, bradycardia, and multiple laryngoscopy attempts during anesthetic induction in InfantsA single-center, retrospective study. Anesthes. 2019;131(4):830-839. Accessed Nov 3, 2019. doi: 10.1097/ALN.0000000000002847.

8. Mamie C, Habre W, Delhumeau C, Argiroffo CB, Morabia A. Incidence and risk factors of perioperative respiratory adverse events in children undergoing elective surgery. Paediatr Anaesth. 2004;14(3):218-224. Accessed Nov 3, 2019. doi: 10.1111/j.1460-9592.2004.01169.x.

9. Petroski A, Frisch A, Joseph N, Carlson JN. Predictors of difficult pediatric intravenous access in a community emergency department. J Vasc Access. 2015;16(6):521-526. Accessed Nov 3, 2019. doi: 10.5301/jva.5000411.

10. Santillanes G, Gausche-Hill M. Pediatric airway management. Emerg Med Clin North Am. 2008;26(4):96-975, ix. Accessed Nov 3, 2019. doi: 10.1016/j.emc.2008.08.004.