Preoperative Assessment

Preoperative assessment begins with a comprehensive history and physical exam best performed by the physician who has the most continuity with the patient. For all children, but especially for neonates, infants, and toddlers, birth history is important. Prematurity can lead to a number of complications, reactive airway disease being the most pertinent for anesthetic management. Prematurity also has implications for the timing of surgery and the need for postoperative observation. Premature infants are more prone to apnea and bradycardia spells and so require a 24-h observation stay with cardiorespiratory monitoring after a general anesthetic until they are 52–60 weeks post-conceptual age, dependent on institutional practice [1, 2].

Past medical history should include craniofacial abnormalities commonly associated with difficult airway management. The most common examples include Pierre Robin sequence, craniofacial dysostosis, mandibulofacial dysostosis/Treacher Collins syndrome, and hemifacial microsomia, but many others exist [3].

Family history should include a history of adverse anesthetic reactions. Although rare, malignant hyperthermia (MH) is a life-threatening condition associated with exposure to volatile anesthetics or the depolarizing neuromuscular blocking drug succinylcholine. Any positive family history of MH should be clearly documented and conveyed to the anesthesia team as it would necessitate an alteration of typical anesthetic management. Resources can be found at www.​mhaus.​org.

One of the most important acute illnesses that is pertinent to anesthetic care of any child but specifically in children presenting for airway procedures is an upper respiratory infection (URI). URIs are ubiquitous in toddlers and young children yet have important implications for timing of the anesthetic and possible complications. Airway surgery puts patients with a URI at a higher risk of adverse events. Multiple studies have shown that children with an active or recent (within 2–4 weeks) URI are more prone to bronchospasm, laryngospasm, breath holding, oxygen desaturation <90%, and overall adverse respiratory events. It would be important to note if a patient has the following independent risk factors for these events: history of prematurity, personal or family history of reactive airway disease or eczema, and second-hand smoke exposure [4, 5]. When a patient has an active or recent URI, the decision to proceed versus cancel and reschedule must be a collaborative one between the surgical and anesthesia team. For some children, it can be hard to find a time when they are completely free of URI symptoms to safely proceed with operative evaluation.

Intraoperative Management

The workup for voice and swallowing disorders is now routinely conducted by aerodigestive programs performing a triple endoscopy, also known as the “triple scope”: laryngoscopy and rigid bronchoscopy, flexible bronchoscopy with bronchoalveolar lavage, and esophagogastroduodenoscopy. This involves coordination among the otolaryngology team, pediatric pulmonary team, and pediatric gastroenterology team.

Laryngoscopy and rigid bronchoscopy can be one of the most challenging anesthetic cases even for an experienced pediatric anesthesiologist. One must balance maintaining spontaneous respiration while also providing a deep plane of anesthesia to prevent movement, coughing, or laryngospasm. This becomes even more challenging with younger patients, as maintaining an adequate depth of anesthesia often comes with significant hypotension. During the procedure itself, end-tidal carbon dioxide monitoring, a standard American Society of Anesthesiology (ASA) monitor, is not reliable, and the anesthesiologist must use auscultation of breath sounds and visual inspection of chest rise as confirmation of ventilation.

In most young children, anesthesia is induced with a volatile anesthetic provided by face mask. Once an adequate depth of anesthesia is achieved, a peripheral intravenous catheter is placed while maintaining spontaneous respirations. Our institutional practice is to start with rigid bronchoscopy. There are two different anesthetic techniques to facilitate rigid bronchoscopy, and choice is determined by anesthesiologist and/or surgeon preference. There is limited evidence to suggest one technique is superior to another [6].

The first option is a total intravenous anesthetic. This is often accomplished with a propofol infusion with or without additional opiate, most commonly fentanyl bolus or remifentanil infusion. It takes time for the propofol to reach a steady state, but the patient often has residual volatile anesthetic from the mask induction to cover this period. The advantage of this technique is providing a measurable amount of anesthetic as well as limiting volatile anesthetic pollution to the operating room and providers.

The second choice is to continue providing anesthesia with inhaled volatile anesthetic. This can also be augmented with additional opiate analgesics. The advantage of this is simplicity, as no additional infusions need to be started. One may be less likely to induce apnea with this technique as well. The main disadvantage is the difficulty in measuring the amount of volatile anesthetic delivered, as delivery is occurring via a side port of a rigid bronchoscope or via an endotracheal tube positioned in the oral cavity. There is also significant amount of waste gas pollution to the operating room as high flows of oxygen are necessary to carry the volatile anesthetic to the patient. According to the Centers for Disease Control (CDC), exposure to high concentrations of waste anesthetic gases, even for a short time, may cause headache, irritability, fatigue, nausea, drowsiness, difficulties with judgment and coordination, and liver and kidney disease [7].

The anesthesia team will often give a dose of steroid (dexamethasone 0.5–1 mg/kg (up to 10 mg)) to prevent airway swelling. They will also provide the proceduralists with topical lidocaine to apply on the true vocal folds. The total dose is split between the otolaryngology team and the pulmonary team who will want to anesthetize the carina as well.

After completion of rigid bronchoscopy, a classic laryngeal mask airway (LMA) is placed to facilitate flexible bronchoscopy by the pulmonary team. Use of an LMA instead of an endotracheal tube allows for a larger flexible bronchoscope to be used. During this time, the anesthetic may proceed with IV anesthesia (propofol), volatile anesthetic (sevoflurane), or a combination of the two. One of the biggest challenges is again maintaining a depth of anesthesia to prevent coughing and movement while attempting to maintain spontaneous respirations. After the pulmonologist preforms bronchoalveolar lavage (BAL), the patient may experience transient desaturation due to shunting in the lung segment that was lavaged. The degree of desaturation is often dependent on the amount of fluid instilled and removed by suction.

The patient’s anesthetic management can proceed in a number of ways for the final step of the procedure, the upper endoscopy performed by the gastroenterologist. If the patient is stable without desaturation after the BAL, the LMA can be removed, and an IV-based anesthetic can proceed with spontaneous ventilation and oxygen delivery via nasal cannula. This technique prevents further airway manipulation and irritation. Certain patients, particularly younger patients, struggle to maintain unobstructed spontaneous respiration with an endoscope in the esophagus. In this case, there are two options. Some gastroenterologists are willing to work around the LMA already in place, although they often prefer to work around a flexible LMA. If this is not an option, or if the patient’s pulmonary status is tenuous after the flexible bronchoscopy, the patient will require endotracheal intubation. This is likely the safest way to proceed, but also the most invasive, and the patient can still struggle with coughing, desaturation, and laryngospasm upon emergence and extubation.

Although this is the typical course, there is currently no national standard for anesthetic management for these procedures, and within a given institution, there is often marked variability between providers. The American Association of Pediatrics (AAP) consensus statement on the structure and function of these programs highlights the benefit of fewer exposures to anesthesia when these services are performed together, yet it makes no mention of anesthetic techniques [8]. It is beneficial for an institution to have an anesthetic guide for management as these patients are often complex and coordination among so many providers on one case can be challenging. At our institution, a clinical guide helped standardize care and management for these procedures.

One final procedure to mention is the drug-induced sleep endoscopy (DISE). This procedure is often requested when there is concern for sleep-disordered breathing or obstructive sleep apnea. The goal for the otolaryngology team is to visualize the upper airway in a state that mimics natural sleep. From an anesthesia standpoint, this can be very challenging. The vast majority of mediations used in anesthesia cause transient respiratory depression and decreased pharyngeal muscle tone. Some otolaryngologists are willing to examine the airway with a small flexible fiberoptic endoscope inserted through the end-tidal sampling line port of the circuit elbow during mask ventilation. Although the anesthesia team will lose end-tidal monitoring during this time, the anesthetic can continue with face mask delivery of volatile anesthetic. Other otolaryngologists prefer to use agents that more closely mimic natural sleep. Our institutional practice limits oral premedications and proceeds with inhalation induction with volatile anesthetic. A dexmedetomidine (selective alpha-2 agonist) bolus is then given over the course of 10 min, while the volatile anesthetic is washed out through spontaneous respiration. We find a small bolus of ketamine (0.5–1 mg/kg) given just before nasal endoscopy helps the patient tolerate the procedure. Both ketamine and dexmedetomidine have the least effects on pharyngeal tone and respiratory drive of the commonly used anesthetic agents. A recently published review on DISE pointed out a lack of agreement for optimal anesthetic management/agents. They described the use of oral premedication, intranasal dexmedetomidine, nitrous oxide, fentanyl, ketamine, and topical anesthesia [9]. Again, standardization of technique within an institution and program will likely improve procedural and diagnostic outcomes.

Postoperative Management

Most patients presenting for triple endoscopy will be candidates for outpatient surgery. During phase 1 recovery, it is important to ensure a patent natural airway and adequate oxygen saturation without supplemental oxygen, especially if the patient underwent BAL. If there is concern for stridor and/or airway edema, racemic epinephrine may be used as a treatment, but the patient will need to stay at least 2 h after administration to ensure they do not have rebound swelling. As none of the endoscopy procedures are particularly painful, postoperative analgesia with acetaminophen is often sufficient. As with all ambulatory surgery patients, discharge readiness should be assessed with a validated tool such as the Pediatric Post Anesthesia Discharge Scoring System (Ped-PADSS). This score measures adequate vital signs, ambulation, nausea and/or vomiting, pain, and surgical bleeding [10]. In rare cases, if oxygen saturation is not adequate, if airway obstruction is present, or patients do not meet the ambulatory discharge criteria above, an inpatient observation may be necessary.