Reflux associated apnea in infants: evidence for a laryngeal chemoreflex.

The mucosa covering the interarytenoid space at the entrance to the larynx contains specialized nerve endings (receptors) that are stimulated when a fluid comes into contact with the mucosal surface. These receptors mediate several aspiration preventive reflex responses, which include swallowing, cessation of breathing, airway constriction or closure, and coughing. The laryngeal receptors are more sensitive to water than to saline, and therefore the combined reflex response to receptor stimulation is termed the "laryngeal chemoreflex." This reflex can be activated during regurgitation of gastric contents into the pharynx, in which case the several components of the reflex serve to prevent intrapulmonary aspiration of gastric fluid. In certain infants a hyperactive laryngeal chemoreflex may cause episodic prolonged apnea. Such reflex-mediated apnea has been implicated in several kinds of prolonged infantile apnea, including apea of prematurity, gastric regurgitation-related apnea, and apnea associated with upper respiratory infection.