June 2002 / Volume 47 / Number 6 / Page 662
The Use of the Air Leak Test and Corticosteroids in Intubated Children: A Survey of Pediatric Critical Care Fellowship Directors
Tracheal intubation can result in damage to the larynx, manifested by inflammation and swelling, leading to complications such as stridor and upper airway obstruction. In neonates and infants the presence of post-extubation stridor and the number of endotracheal tube (ETT) insertions directly correlate with the risk of developing subglottic stenosis.
The air leak test measures the air pressure required to produce an audible (to a stethoscope placed over the larynx) rush of air around the ETT. The air leak test has been used to predict successful extubation among children with viral croup and after tracheal surgery -- conditions that can produce upper airway edema. It has become a common practice in many centers to routinely test for air leak prior to extubation in all intubated children, regardless of the underlying pathology. A study by Kemper et al of pediatric trauma patients found that the absence of an air leak at 30 cm H2O pressure might predict extubation failure.
The utility of steroids in reducing post-extubation laryngeal edema is uncertain. A single dose of hydrocortisone prior to extubation showed no beneficial effect in adults, whereas in pre-term infants dexamethasone prevented post-extubation airway obstruction. Studies of the use of dexamethasone to prevent airway obstruction and post-extubation stridor in children have given mixed results. Children in certain age groups are more susceptible to post-intubation laryngeal edema, yet attempts to stratify children by age showed no advantage from dexamethasone in preventing post-extubation stridor. Uncertainty also exists regarding steroid dosing regimen prior to extubation.
The use of cuffed ETTs in children < 7 years of age has not been recommended by the Pediatric Advanced Life Support Committee of the American Heart Association, but it has been a common practice to use cuffed ETTs in young children. ETT size may affect airway edema. Whether down-sizing the ETT in the absence of an air leak decreases the development of airway edema or stridor is unknown.
Our objective was to determine areas of consensus and controversy among pediatric intensivists in the management of airway edema. A questionnaire was distributed to all North American pediatric critical care fellowship directors affiliated with medical school teaching hospitals. The survey was conducted to assess practice patterns in areas of controversy, and the information generated from our survey will provide data to frame future research questions and improve our current practice.