Effect of anesthetics on mortality and kidney lesions caused by hypotension

Unanesthetized rats and rats anesthetized with a number of anesthetics were bled according to different bleeding schedules. In rats bled for 60 min against 30-50 mm Hg marked protection against mortality and the occurrence of kidney lesions was obtained with pentobarbital-Na, enflurane, halothane and methoxyflurane. Less protection was provided by diethylether while little or no protection was obtained with ethylurethane, trichloroethylene and ketamine. Protection was afforded by pentobarbital-Na in the dose range of 50 mg/kg to 6.2 mg/kg. Slight protection was afforded by dehydrobenzperidol. If pentobarbital-Na was administered after the bleeding the protection was slight. At bleeding pressures below 30 mm Hg the protective effect disappeared for all anesthetics used. Protection was not correlated with either depth of anesthesia, hypotensive effect or reduction of the maximum bleeding volume. However, a correlation was found between protective effect and the retardation of bleeding and the prolongation of survival time caused by the different anesthetics.