Site of upper airway obstruction in infants following an acute life-threatening event.

Twenty-five patients were screened following an acute life-threatening event for the presence of obstructive and mixed apnea. Simultaneous cardiorespiratory monitoring with fiberoptic laryngoscopy was performed to identify the site of upper airway obstruction during these episodes. In 3 of these subjects, who had been born prematurely, obstruction was observed at the laryngeal level, with the arytenoid masses and aryepiglottic folds closing over across the vocal cords. Such closure was also observed during periodic breathing, which was found to be prominent in 4 of the infants studied. The possible role of laryngeal reflexes as a mechanism for these events is discussed.