Detrimental effects of ethanol on murine frostbite

Many references have been made concerning the adverse effects of ethanol in human frostbite. The lack of experimental evidence to support this belief prompted the authors to undertake this investigation. Nineteen Swiss-Webster mice (25 +/- 2 gm) were given intraperitoneal injections of 0.2 cm3 of 50 per cent ethanol (group A) or 0.2 cm3 saline (group B). Thirty minutes later, the animals were anesthetized with pentobarbital (group A 30 mg/kg; group B 50 mg/kg). Lower barbiturate dose was used in group A because of the synergistic central nervous system depressant effect when combined with alcohol. Tail lengths of all animals were measured. The tails were immersed in a 50 per cent ethylene glycol solution (-18 C) for 6 min and then thawed at room temperature (24 C). At 24 hrs, tail circulation was assessed by length of tail perfused with the vital dye alphazurine 2 gm given intraperitoneally. Mortality to 14 days was recorded. All animals survived the initial anesthetic and/or alcohol administration. Group A had a statistically significant (P less than 0.001 Students t test) decrease in length of tail perfused compared with group B at 24 hours (0.98 +/- 0.19 cm versus 2.58 +/- 0.23 cm). Fourteen day survival was 10 per cent in group A compared with 89 per cent in group B (P less than 0.001, chi-square test). We conclude that ethanol has significant adverse effects on tissue perfusion and mortality associated with severe murine frostbite.