A BRONCHOSCOPIC, COMPUTER-ASSISTED EXAMINATION OF THE CHANGES IN DIMENSION OF THE INFANT TRACHEAL LUMEN WITH CHANGES IN HEAD POSITION - IMPLICATIONS FOR EMERGENCY AIRWAY MANAGEMENT

Background Resuscitation guidelines caution against extreme extension or flexion of an infant's head because tracheal obstruction may occur. No data support this recommendation. The authors therefore examined t he dimensions of the tracheal lumen in neutral, extended, and flexed h ead positions in infants undergoing general endotracheal anesthesia fo r elective surgery. Methods: Eighteen healthy full-term infants were s tudied. A flexible fiberoptic bronchoscope was passed through a previo usly inserted endotracheal tube and positioned above the cricoid carti lage. Video recordings were taken in each of three head positions. Rec ordings were analyzed by an investigator blinded to head position. A c omputer-digitized technique was used to measure anterior-posterior and lateral dimensions and cross-sectional area. Data were analyzed using paired t tests and sign tests. Results: No significant differences in mean tracheal dimensions with changes in head position were found. No infant had complete tracheal obstruction, Infants were equally as lik ely to have a small increase as they were to have a small decrease in tracheal dimension with changes in head position. Conclusions: Despite the belief that infants and neonates have obstruction at the level of the trachea with extreme positions of the head, the authors were unab le to demonstrate this phenomenon.