Anatomy

Several anatomic features of the pediatric respiratory tract predispose the young patient to obstruction and collapse of both large and small airways. A child’s upper respiratory tract is prone to obstruction at several sites. The narrow nasal passages, tongue/oral cavity disproportion, and decreased airway diameter characteristic of infants and young children predispose this patient population to partial or complete upper airway obstruction (Figure 5-2).^1,2 Additional risk may be generated by routine office procedures: a tightly clamped mask over the nares, a mouth pack depressing the oral cavity floor, or a retractor posteriorly displacing the tongue all may increase the likelihood of upper airway obstruction. The secretions and edema associated with upper respiratory infections also can compromise the pediatric airway and should be kept in mind when an acutely ill child reports for an elective procedure. Bronchospasm, laryngospasm, acute subglottic edema with stridor, intraoperative and perioperative hypoxia, atelectasis, and postextubation croup are among the complications of anesthesia that are reported after the child with respiratory infection has surgery, particularly involving intubation. In the past, most clinicians recommended postponement of an elective procedure until the child had been free of symptoms for 1 week. Although there is no consensus on indications for canceling an elective procedure without endotracheal intubation, literature suggests that signs and symptoms of lower tract involvement such as fever of 38° C (100.4° F) or higher, lethargy, productive cough, wheezing, or tachypnea, in addition to a history of asthma, are more commonly associated with anesthesia-related morbidity. Similarly, if a bacterial infection is suspected, patients should be placed on antibiotic therapy and their procedure postponed for at least 4 weeks.^3–5 Children with airway anomalies as part of a genetic syndrome should be approached with special caution (Table 5-1). Children with a history of prolonged endotracheal intubation may have subglottic stenosis and thus may be prone to airway obstruction. In addition, extremely obese children (body mass index higher than 40) may have airway problems related to excessive neck tissue.^6,7