Low-level hyperbaric ethanol antagonism in mice. Dose and pressure response

Dose- and pressure-related interactions between ethanol anesthesia and low-level hyperbaric helium-oxygen environments were studied in mice using conditions which eliminated the possibility of hypoxia during compression and hyperbaric helium-induced hypothermia. Hyperbaric helium-oxygen (1-12 atmospheres absolute) reduced sleep time in a pressure-related manner. The degree of maximum ethanol antagonism decreased as the ethanol dose increased (3.2, 3.6, and 4.0g/kg). The results are consistent with membrane theories of general anesthesia and suggest a possible common mechanism between ethanol antagonism at low hyperbaric pressure and high-pressure reversal of anesthesia.