Effect of hypothermia on the pharmacokinetics of ethanol in piglets

The effect of hypothermia (29 C) on the pharmacokinetics of ethanol was studied in eight piglets serving as their own normothermic controls. Ten milliliters of 12% ethanol per kilogram were infused over 30 minutes, and serum ethanol concentrations were measured for seven hours. Ethanol concentration data were fitted to one-compartment open model assuming Michaelis Menten elimination kinetics. During hypothermia, ethanol concentrations were consistently higher than during normothermia. This observation could be explained by both a significantly smaller distribution volume of ethanol during hypothermia (0.71 +/- 0.03 L/kg at 29 C and 0.84 +/- 0.05 L/kg at 37 C, P less than .02) and a significantly slower maximum velocity of metabolism of ethanol (Vm) during hypothermia (1.12 +/- 0.11 mg/kg.min vs. 1.83 +/- 0.21 mg/kg.min, P less than .01). Our study indicates that during hypothermia, ethanol stays significantly longer in the circulation in piglets. Potentially, this may contribute to a more profound effect from the ethanol.