The effect of ethyl alcohol on the sensitivity of upper airway reflexes.

The effect of ethyl alcohol on upper airway reflex sensitivity (UARS) has not been previously investigated in humans. Using a technique that we have previously described, intermittent breaths of low concentrations of ammonia vapour were used to measure the effect of ethyl alcohol 0.55-0.66 g/kg on UARS in ten healthy male volunteers. The depression of upper airway reflexes that occurred following ingestion of ethyl alcohol was maximum at 60 min and returned to baseline by 150 min. This dose of ethyl alcohol was insufficient to produce statistically significant depression of UARS. The blood alcohol levels achieved showed a wide range with a mean of 78.9 mg/100 ml (SEM 10.3). Individual subjects who had blood alcohol levels in excess of 100 mg/100 ml displayed much greater depression of UARS. In conclusion, 0.55-0.66 g/kg ethyl alcohol given to healthy male volunteers does not produce significant depression of UARS as measured using an ammonia stimulus technique.