Ronald S. Litman

Clinical Practice Guideline Tonsillectomy in Children

Objective Tonsillectomy is one of the most common surgical procedures in the United States, with more than 530 000 procedures performed annually in children younger than 15 years. Tonsillectomy is defined as a surgical procedure performed with or without adenoidectomy that completely removes the tonsil including its capsule by dissecting the peritonsillar space between the tonsil capsule and the muscular wall. Depending on the context in which it is used, it may indicate tonsillectomy with adenoidectomy, especially in relation to sleep-disordered breathing. This guideline provides evidence-based recommendations on the preoperative, intraoperative, and postoperative care and management of children 1 to 18 years old under consideration for tonsillectomy. In addition, this guideline is intended for all clinicians in any setting who interact with children 1 to 18 years of age who may be candidates for tonsillectomy. Purpose The primary purpose of this guideline is to provide clinicians with evidence-based guidance in identifying children who are the best candidates for tonsillectomy. Secondary objectives are to optimize the perioperative management of children undergoing tonsillectomy, emphasize the need for evaluation and intervention in special populations, improve counseling and education of families of children who are considering tonsillectomy for their child, highlight the management options for patients with modifying factors, and reduce inappropriate or unnecessary variations in care. Results The panel made a strong recommendation that clinicians should administer a single, intraoperative dose of intravenous dexamethasone to children undergoing tonsillectomy. The panel made a strong recommendation against clinicians routinely administering or prescribing perioperative antibiotics to children undergoing tonsillectomy. The panel made recommendations for (1) watchful waiting for recurrent throat infection if there have been fewer than 7 episodes in the past year or fewer than 5 episodes per year in the past 2 years or fewer than 3 episodes per year in the past 3 years; (2) assessing the child with recurrent throat infection who does not meet criteria in statement 2 for modifying factors that may nonetheless favor tonsillectomy, which may include but are not limited to multiple antibiotic allergy/intolerance, periodic fever, aphthous stomatitis, pharyngitis and adenitis, or history of peritonsillar abscess; (3) asking caregivers of children with sleep-disordered breathing and tonsil hypertrophy about comorbid conditions that might improve after tonsillectomy, including growth retardation, poor school performance, enuresis, and behavioral problems; (4) counseling caregivers about tonsillectomy as a means to improve health in children with abnormal polysomnography who also have tonsil hypertrophy and sleep-disordered breathing; (5) counseling caregivers that sleep-disordered breathing may persist or recur after tonsillectomy and may require further management; (6) advocating for pain management after tonsillectomy and educating caregivers about the importance of managing and reassessing pain; and (7) clinicians who perform tonsillectomy should determine their rate of primary and secondary posttonsillectomy hemorrhage at least annually. The panel offered options to recommend tonsillectomy for recurrent throat infection with a frequency of at least 7 episodes in the past year or at least 5 episodes per year for 2 years or at least 3 episodes per year for 3 years with documentation in the medical record for each episode of sore throat and 1 or more of the following: temperature >38.3°C, cervical adenopathy, tonsillar exudate, or positive test for group A β-hemolytic streptococcus.

Developmental changes of laryngeal dimensions in unparalyzed, sedated children.

Background Knowledge of the influence of age on laryngeal dimensions is essential for all practitioners whose interest is the pediatric airway. Early cadaver studies documented that the larynx is conically shaped, with the apex of the cone caudally positioned at the nondistensible cricoid cartilage. These dimensions change during childhood, as the larynx assumes a more cylindrical shape. The authors analyzed laryngeal dimensions during development to determine if this relationship continues in unparalyzed children in whom laryngeal muscles are tonically active. The authors determined the relationships between the vocal cord, sub–vocal cord, and cricoid ring dimensions and the influence of age on these relationships. Methods Infants and children undergoing magnetic resonance imaging with propofol sedation had determinations of the transverse and anterior–posterior (AP) dimensions of the larynx at the most cephalad level of the larynx (vocal cords) and the most caudad level (cricoid). Most patients had an additional measurement (sub–vocal cord) at a level between the vocal cords and the cricoid ring. Relationships were obtained by plotting age against laryngeal dimensions and the ratio of laryngeal dimensions at different levels within the larynx. Results The authors measured transverse and AP laryngeal dimensions in 99 children, aged 2 months–13 yr. The relationship between the transverse and AP dimensions at all levels of the larynx did not change during development. Transverse and AP dimensions increased linearly with age at all levels of the larynx. In all children studied, the narrowest portion of the larynx was the transverse dimension at the level of the vocal cords. Transverse dimensions increased linearly in a caudad direction through the larynx (P < 0.001), while AP dimensions did not change relative to laryngeal level. The shape of the cricoid ring did not change throughout childhood. Conclusions In sedated, unparalyzed children, the narrowest portions of the larynx are the glottic opening (vocal cord level) and the immediate sub–vocal cord level, and there is no change in the relationships of these dimensions relative to cricoid dimensions throughout childhood.

Malignant hyperthermia and muscular dystrophies.

BACKGROUND: Patients with muscular dystrophy have been reported to experience a variety of life-threatening complications during and after general anesthesia. We performed a systematic analysis to define the spectrum of anesthetic-related complications in patients with muscular dystrophy, with an emphasis on malignant hyperthermia susceptibility. METHODS: A literature search was undertaken using multiple search engines and the appropriate articles were reviewed by the authors to determine anesthetic-associated complications in patients with muscular dystrophy. Of all the types of muscular dystrophy, Duchenne muscular dystrophy (DMD) and Becker dystrophy (BD) represent nearly all the anesthesia-related reports. RESULTS: Anesthetic complications in patients with DMD and BD include intraoperative heart failure, inhaled anesthetic-related rhabdomyolysis (absence of succinylcholine), and succinylcholine-induced rhabdomyolysis and hyperkalemia. CONCLUSION: We did not find an increased risk of malignant hyperthermia susceptibility in patients with DMD or BD compared with the general population. However, dystrophic patients who are exposed to inhaled anesthetics may develop disease-related cardiac complications, or rarely, a malignant hyperthermia-like syndrome characterized by rhabdomyolysis. This latter complication may also occur postoperatively. Succinylcholine administration is associated with life-threatening hyperkalemia and should be avoided in patients with DMD and BD.

Breathing patterns and levels of consciousness in children during administration of nitrous oxide after oral midazolam premedication

PURPOSE The combination of midazolam and nitrous oxide is commonly used to achieve sedation and analgesia during pediatric oral procedures, yet there are few, if any, data that illustrate the ventilatory effects of N2O in children, especially when used in combination with additional central nervous system (CNS) depressants. It was hypothesized that the addition of N2O inhalation to oral midazolam premedication would enhance the sedative effects of the midazolam and add analgesia without causing significant respiratory depression. The purpose of this study was to test this hypothesis. MATERIALS AND METHODS Thirty-four healthy children about to undergo restorative dental treatment under general anesthesia were premedicated with oral midazolam, 0.7 mg/kg, and were then exposed to 40% N2O for 15 minutes after a 5-minute control period. The effect of adding N2O on SpO2, respiratory rate, PETCO2, VT, and VT/TI was examined and the levels of consciousness (conscious vs deep sedation) before and during N2O inhalation were determined. RESULTS During the course of the study, no child developed hypoxemia (SpO2 < 92%) nor clinically significant upper airway obstruction. Four children who did not develop hypoventilation (defined as PETCO2 > 45 mm Hg) during the control period did so after initiation of N2O. Overall, there were no significant differences in SpO2, PETCO2, VT, or VT/TI between the control and study periods. However, respiratory rates were significantly higher in the first 10 minutes of N2O inhalation when compared with the control period. Before starting N2O administration, 14 children were not clinically sedated, 19 children met the criteria for conscious sedation, and one child met the criteria for deep sedation. At the end of 15 minutes of N2O inhalation, 12 children were not clinically sedated, 17 children met the definition of conscious sedation, three were deeply sedated, and one child had no response to IV insertion, implying a state of general anesthesia. There were no differences in sedation scores between the control and study periods (P = .6). Overall, seven children had an increase in their sedation score while breathing N2O, four had a decrease in their sedation score, and 22 had no change. CONCLUSIONS The addition of 40% N2O to oral midazolam, 0.7 mg/kg, did not result in clinically meaningful respiratory depression nor upper airway obstruction, but did, in some children, cause an increase in the level of sedation beyond simple conscious sedation.

Anesthesia for tracheal or bronchial foreign body removal in children: an analysis of ninety-four cases.

IMPLICATIONS This report is a description of the ventilation techniques used in 94 children undergoing general anesthesia for foreign body removal of the bronchus. No particular technique was found to be associated with a greater incidence of adverse outcomes.

Effect of Lateral Positioning on Upper Airway Size and Morphology in Sedated Children

Background:Lateral positioning decreases upper airway obstruction in paralyzed, anesthetized adults and in individuals with sleep apnea during sleep. The authors hypothesized that lateral positioning increases upper airway cross-sectional area and total upper airway volume when compared with the supine position in sedated, spontaneously breathing children. Methods:Children aged 2–12 yr requiring magnetic resonance imaging examination of the head or neck region using deep sedation with propofol were studied. Exclusion criteria included any type of anatomical or neurologic entity that could influence upper airway shape or size. T1 axial scans of the upper airway were obtained in the supine and lateral positions, with the head and neck axes maintained neutral. Using software based on fuzzy connectedness segmentation (3D-VIEWNIX; Medical Imaging Processing Group, University of Pennsylvania, Philadelphia, PA), the magnetic resonance images were processed and segmented to render a three-dimensional reconstruction of the upper airway. Total airway volumes and cross-sectional areas were computed between the nasal vomer and the vocal cords. Two-way paired t tests were used to compare airway sizes between supine and lateral positions. Results:Sixteen of 17 children analyzed had increases in upper airway total volume. The total airway volume (mean ± SD) was 6.0 ± 2.9 ml3 in the supine position and 8.7 ± 2.5 ml3 in the lateral position (P < 0.001). All noncartilaginous areas of the upper airway increased in area in the lateral compared with the supine position. The region between the tip of the epiglottis and vocal cords demonstrated the greatest relative percent change. Conclusions:The upper airway of a sedated, spontaneously breathing child widens in the lateral position. The region between the tip of the epiglottis and the vocal cords demonstrates the greatest relative percent increase in size.

Pediatric airway foreign body retrieval: surgical and anesthetic perspectives

Airway foreign body aspiration most commonly occurs in young children and is associated with a high rate of airway distress, morbidity, and mortality. The presenting symptoms of foreign body aspiration range from none to severe airway obstruction, and may often be innocuous and nonspecific. In the absence of a choking or aspiration event, the diagnosis may be delayed for weeks to months and contribute to worsening lung disease. Radiography and high resolution CT scan may contribute to the eventual diagnosis. Bronchoscopy is used to confirm the diagnosis and retrieve the object. The safest method of removing an airway foreign body is by utilizing general anesthesia. Communication between anesthesiologist and surgeon is essential for optimal outcome. The choice between maintenance of spontaneous and controlled ventilation is often based on personal preference and does not appear to affect the outcome of the procedure. Complications are related to the actual obstruction and to the retrieval of the impacted object. The localized inflammation and irritation that result from the impacted object can lead to bronchitis, tracheitis, atelectasis, and pneumonia.

Airway management complications in children with difficult tracheal intubation from the Pediatric Difficult Intubation (PeDI) registry: a prospective cohort analysis

BACKGROUND Despite the established vulnerability of children during airway management, remarkably little is known about complications in children with difficult tracheal intubation. To address this concern, we developed a multicentre registry (Pediatric Difficult Intubation [PeDI]) to characterise risk factors for difficult tracheal intubation, establish the success rates of various tracheal intubation techniques, catalogue the complications of children with difficult tracheal intubation, and establish the effect of more than two tracheal intubation attempts on complications. METHODS The PeDI registry consists of prospectively collected tracheal intubation data from 13 childrens hospitals in the USA. We established standard data collection methods before implementing the secure web-based registry. After establishing standard definitions, we collected and analysed patient, clinician, and practice data and tracheal intubation outcomes. We categorised complications as severe or non-severe. FINDINGS Between August, 2012, and January, 2015, 1018 difficult paediatric tracheal intubation encounters were done. The most frequently attempted first tracheal intubation techniques were direct laryngoscopy (n=461, 46%), fibre-optic bronchoscopy (n=284 [28%]), and indirect video laryngoscopy (n=183 [18%]) with first attempt success rates of 16 (3%) of 461 with direct laryngoscopy, 153 (54%) of 284 with fibre-optic bronchoscopy, and 101 (55%) of 183 with indirect video laryngoscopy. Tracheal intubation failed in 19 (2%) of cases. 204 (20%) children had at least one complication; 30 (3%) of these were severe and 192 (19%) were non-severe. The most common severe complication was cardiac arrest, which occurred in 15 (2%) patients. The occurrence of complications was associated with more than two tracheal intubation attempts, a weight of less than 10 kg, short thyromental distance, and three direct laryngoscopy attempts before an indirect technique. Temporary hypoxaemia was the most frequent non-severe complication. INTERPRETATION More than two direct laryngoscopy attempts in children with difficult tracheal intubation are associated with a high failure rate and an increased incidence of severe complications. These results suggest that limiting the number of direct laryngoscopy attempts and quickly transitioning to an indirect technique when direct laryngoscopy fails would enhance patient safety. FUNDING None.

The Pediatric Airway

Abstract This chapter reviews the developmental anatomy and physiology of the pediatric upper airway as it relates to the practice of pediatric anesthesia. Differences between the pediatric and adult airways are important determinants of anesthetic techniques. Knowledge of normal developmental anatomy and physiologic function is required to understand and manage both the normal and the pathologic airways of infants and children. Techniques of mask ventilation, oral and nasal airway placement, use of supraglottic devices, and tracheal intubation are reviewed for normal and anatomically abnormal pediatric patients.

Morphologic changes in the upper airway of children during awakening from propofol administration.

Background The purpose of this study was to determine the morphologic changes that occur in the upper airway of children during awakening from propofol sedation. Methods Children undergoing magnetic resonance imaging of the head underwent additional scans of the upper airway during deep sedation with propofol; this was repeated on awakening. Axial views were obtained at the most posterior sites of the pharynx at the levels of the soft palate and tongue. Measurements were then obtained of the anterior–posterior (A-P) diameter, transverse diameter, and cross-sectional areas at these levels. Results Data were obtained on 16 children, aged 10 months to 7 yr. In both sedated and awakening states, most children had the smallest cross-sectional area of the pharynx at the level of the soft palate. During the sedated state, at the soft palate level, the transverse diameter was most narrow in 11 children, the A-P diameter was most narrow in 1 child, and they were equal in 2 children. During the sedated state, at the level of the tongue, the transverse diameter was most narrow in 9 children, the A-P diameter was most narrow in 5 children, and they were equal in 2 children. During awakening, at the soft palate level, the transverse diameter was most narrow in none of the children, the A-P diameter was most narrow in 13 children, and they were equal in 1 child. At the level of the tongue, the transverse diameter was most narrow in 4 children, and the A-P diameter was most narrow in 12 children. During awakening, the A-P diameter of the pharynx at the level of the soft palate decreased in 12 children, increased in 1 child, and remained the same in 1 child. (P < 0.001). The transverse diameter increased in 11 children, decreased in 1 child, and remained the same in 2 children (P = 0.001). The cross-sectional area at the level of the soft palate increased in 4 children, decreased in 8 children, and stayed the same in 2 children (P = 0.5). During awakening, the A-P diameter of the pharynx at the level of the tongue decreased in 11 children, increased in 4 children, and remained the same in 1 child. (P = 0.01). The transverse diameter increased in 11 children and decreased in 5 children (P = 0.07). The cross-sectional area at the level of the tongue increased in 7 children, decreased in 7 children, and stayed the same in 2 children (P = 0.9). Conclusions The dimensions of the upper airways of children change shape significantly on awakening from propofol sedation. When sedated, the upper airway is oblong shaped, with the A-P diameter larger than the transverse diameter. On awakening, the shape of the upper airway in most children changed such that the transverse diameter was larger. Cross-sectional areas between sedated and awakening states were unchanged. These changes may reflect the differential effects of propofol on upper airway musculature during awakening.