Effect of alcohol on apnea reflexes in young lambs

Abstract

The effect of alcohol on 2 apnea reflexes considered to be protective mechanisms through which animals and humans preserve vital functions while they are submerged in water was investigated. The laryngeal chemoreflex and the trigeminal diving reflex were studied in unanesthetized 1- 3-wk-old lambs. Reflex stimulation resulted in reduced ventilation or apena, bradycardia, hypertension and blood flow redistribution in the dive pattern. After alcohol, reflex stimulation resulted in increase apnea response, preserved blood flow redistribution, but less hypertension. The onset of regular breathing following laryngeal water stimulation was significantly delayed, after alcohol, and mechanical ventilation was used in 3 lambs to terminate the prolonged poststimulus apnea. Airway occlusion pressure, an index of neuromuscular inspiratory drive, decreased significantly after alchol. Alcohol has a potent effect on apnea reflex responses. The effect of alcohol on respiratory drive and on the apnea reflex response should be considered when humans ingest alcohol, in particular by those participating in water sports.