Pediatric Anesthesia 2009 19 (Suppl. 1): 88–99 doi:10.1111/j.1460-9592.2009.03005.x
Review article Upper airway obstruction in children
IAIN A. BRUCE MD, FRCS (ORL-HNS) AND MICHAEL P. ROTHERA FRCS Department of Paediatric ENT, Royal Manchester Children’s Hospital, Manchester, UK
Introduction redundant arytenoid mucosa prolapsing into the glottis and a long curled epiglottis (Figure 2). Surgical Poiseuille’s law is central to the understanding and management of the condition is largely based on management of all airway obstructions in children, correction of these anatomical anomalies. The natural with the clinical impact of even a small reduction in history of the inspiratory stridor is to often worsen radius being compounded by the inverse relation- initially for 6–9 months, before gradually improving, ship of the resistance to the radius to the power 4. with most children being free of symptoms by Indeed deterioration from a ‘mild’ obstruction to life 18–24 months (1). In the absence of atypical symp- threatening airway compromise may be heralded by toms (e.g. cyanosis, altered cry, choking with feeds), slight decrease in airway diameter (Figure 1). Suc- which could suggest an alternative diagnosis or the cessful outcome in all cases of childhood airway presence of synchronous lesions elsewhere in the obstruction is dependant upon the efficient cooper- airway, the condition may be diagnosed by awake ation between suitably experienced otolaryngolo- flexible fibreoptic laryngoscopy (FFL) in the outpa- gists, anesthetists, and intensivists. tient department. Laryngomalacia can be classified The aim of this article is to discuss the presenta- into three types dependant on site of the abnormality tion, assessment, and management of the common (1). Type 1 is due to prolapse of redundant arytenoid causes of childhood airway obstruction as seen in a mucosa into the glottis. Type 2 is a result of short tertiary level unit. Traditionally, airway manage- aryepiglottic folds and Type 3 is characterized by ment often comprised tracheostomy insertion, but collapse of the epiglottis posteriorly over the glottis. It the development of endoscopic techniques has is our departmental policy to perform rigid endos- superseded this in an ever increasing proportion of copy in the following circumstances: (i) severe pro- cases. Treatment strategies and principles will be gressive symptoms; (ii) atypical symptoms; (iii) FFL highlighted and placed in context with results inconclusive; and (iv) clinical or fibreoptic suspicion reported in the literature. of a synchronous airway lesion (SAL). The possibility of an SAL has lead some authors to advocate rigid Laryngomalacia endoscopy in all cases of suspected laryngomalacia (2). However, although the rate of SALs in the Laryngomalacia is the commonest cause of congenital literature is significant (20–30%) (1, 3, 4) the impact stridor. The presenting symptom is usually inspira- upon outcome and time to symptom resolution has tory stridor commencing within the first 2 weeks of been shown to be negligible (3, 4). Laryngomalacia, life, exacerbated by feeding, agitation, and lying in the like vocal cord palsy (VCP), is a dynamic condition supine position. The airway obstruction results from and therefore, if formal airway assessment is collapse of supraglottic structures on inspiration. The indicated, it should be performed under general etiology is not fully understood, but the condition is anesthesia with the child breathing spontaneously. consistently associated with certain anatomical Supraglottic collapse is most obvious during the abnormalities, namely short aryepiglottic folds, ‘waking phase’ at the end of the procedure. The majority of children will not require surgical Correspondence to: Iain A. Bruce, Department of Paediatric ENT, Royal Manchester Children’s Hospital, Manchester, UK (email: intervention, with the remaining 5–10% requiring [email protected]). some form of surgical treatment (1, 4). Surgical