Cardiovascular effects of pentobarbital in pigs, and the lack of response to naloxone in pentobarbital induced circulatory failure.

The hemodynamic effects of pentobarbital were tested in an experimental model used for cardiovascular research. Anesthesia was induced with an i.v. bolus and maintained with a continuous infusion of pentobarbital. The cardiovascular performance was then evaluated at various pentobarbital plasma concentrations ranging from 25 to 100 mg X l-1. Optimal experimental conditions were found at plasma pentobarbital concentrations within the range 40-60 mg X l-1, as the animals were well anesthetized with intact hemodynamics or ECG. The method of continuous pentobarbital administration seems advantageous for experimental research. Circulatory impairment following pentobarbital overdose was not affected by naloxone.