Providing safe and effective anesthesia for the pediatric population is an undertaking that involves several unique challenges the anesthesiologist must consider. To the untrained, it would seem everything is just smaller, however neonates, infants, and young children all pose differing challenges. In fact, there can be more variation from patient to patient in pediatrics than an adult provider might find in a busy surgical suite. Children are obviously smaller in stature, but their body proportions and organ functionality are also different. Tissues throughout the body change in quality with age, which makes them more vulnerable to injury by forces such as pressure, friction, tension, shear, etc. For the anesthesiologist, every act from mask ventilation to patient positioning must take this into strong consideration as the consequences of unintended injury can be severe, long lasting, and costly. There is no safety net for a lack of attention to detail, as errors like connecting a ventilator with tidal volumes set for a teenager to the airway of an infant can cause harm with the delivery of just a single breath. One can lethally overdose an infant with medication by administering a drug without confirming its concentration within a syringe. Providers must think and act quickly as there are no “standard” doses or “one size fits all” tools or techniques that can be applied uniformly to all pediatric patients, especially in life-threatening situations such as cardiopulmonary arrest. Furthermore, a heightened level of awareness must be exercised as a child’s status can change quickly without warning and can rapidly deteriorate if the problem is not noticed, correctly diagnosed, and intervened upon immediately.
Preoperatively, children are very prone to anxiety as they often have little or no understanding of anesthesia or surgery or may anticipate a painful experience based on their knowledge or prior experience. In addition, several different providers will be involved in perioperative care but will be perceived as strangers by young patients, making compliance during history/physical exam, induction of anesthesia, and awake procedures such as IV placement very challenging. Due to this concern, children are commonly anesthetized using a mask induction with placement of invasive line(s) after induction. Interventions such as midazolam premedication, parental presence, patient education, child life play therapy, distraction with books, toys, etc., are all options to treat and/or prevent preoperative anxiety.2,6 According to Fortier and Kaplan, 60% of pediatric patients experience preoperative anxiety and 25% of children who receive no prophylaxis experience forceful induction of anesthesia, which can lead to further negative sequelae.6 Monitoring in pediatric anesthesia is performed for similar indications to that seen in adults, however EKG leads and non-invasive blood pressure cuff are often placed after induction as they can also precipitate anxiety. Conversely, an oxygen saturation sensor is considered an essential monitor for anesthetic induction in children given their high risk for adverse respiratory events.
Generally, adolescents are able to tolerate premedication with pills and/or placement of an IV prior to induction of anesthesia but this can be variable, especially in patients with mental or behavioral disorders. If intravenous access is required prior to induction for younger children, eutectic mixture of local anesthetic (EMLA) cream, local anesthetic spray, cold topical spray, or another form of anesthetic may be used, however none of the currently available methods reliably produce ideal conditions for venous cannulation. A significant amount of onset time is required after EMLA application (~60 mins or more) prior to peripheral IV attempt and the local anesthetic may make the vessel more difficult to cannulate.9 If the anesthetized vessel infiltrates during or after placement, another site must be anesthetized prior to placement which can cause significant delays in procedural start time.
Regarding preoperative fasting, this is widely recommended in adults to reduce gastric volume, however the risk of aspiration must be weighed against that of hypovolemia and hypoglycemia for children, especially in infants.1 Fluid management for small children must also be done meticulously as one can easily overload a small child using a standard infusion setup if it is inadvertently left running during the case. Healthy children often tolerate this as their kidney function is substantial enough to handle large increases in circulating volume, however children with neurologic, cardiac, pulmonary, renal, endocrine, or metabolic derangements should have a fluid management plan prior to induction. Fluid management may also be dictated by the nature of the planned surgery. For this reason, a buretrol is often used to control the delivery of IV crystalloid. Buretrol infusers will also minimize the delivery of air into the venous circulation, which can be disastrous in children with patent foramen ovale or septal defects as even small amounts of air can cause cerebral arterial air embolism.
The pediatric airway is different structurally from the mature airway and behaves distinctly during the excitatory stage of anesthesia. Children have a relatively larger tongue and occiput, more collapsible airway, more compliant ribcage tissues, shorter and thinner epiglottis, anteriorly tilted glottis, weaker and less efficient diaphragmatic contraction, and variable primary versus permanent dentition. In addition, the narrowest point in the pediatric airway is at the cricoid cartilage versus the glottis in adults, which can cause difficulty passing ETT distal to glottis and may prompt a post-intubation tube exchange to optimize ventilation. The airway is also more delicate and sensitive to the pressure and micromotion an endotracheal tube cuff can place on the tracheal mucosa.10 Most of these differences make the pediatric airway potentially more difficult to instrument, which can lead to multiple airway attempts, a known risk factor for oxygen desaturation and bradycardia particularly in infants.
Likewise, children are also much more prone to perioperative respiratory adverse events (PRAEs) such as airway obstruction, laryngospasm, bronchospasm, and desaturation. There is potential for obstruction or laryngospasm to occur prior to placement of IV access after an inhalational induction, in which case the provider must be prepared to abort IV placement and re-establish a patent airway promptly. For this reason, an oxygen saturation probe is placed pre-induction due to the rapid desaturation that occurs during apnea given a child’s relatively high metabolic rate. These patients proceed quickly from apnea to hypoxia, bradycardia, hypotension, and cardiac arrest, which makes recognizing and treating these complications quickly of paramount importance.
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. https://anesthesiology.pubs.asahq.org/article.aspx?articleid=2738236. 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.