Arrhythmogenic Plasma Levels of Epinephrine during Halothane, Enflurane, and Pentobarbital Anesthesia in the Dog

Plasma levels of epinephrine which correspond to the arrhythmogenic doses were determined during halothane, enflurane, and pentobarbital anesthesia in the dog. The arrhythmogenic dose was established by a series of 3-min infusion of epinephrine at 10-min intervals. The mean values of the arrhythmogenic doses and the corresponding plasma levels of epinephrine were: 2.18 micrograms X kg-1 X min-1 and 38.7 ng/ml during halothane; 11.43 micrograms X kg-1 X min-1 and 206.3 ng/ml during enflurane; and 15.27 micrograms X kg-1 X min-1 and 296.5 ng/ml during pentobarbital anesthesia. The arrhythmogenic plasma levels of norepinephrine during halothane anesthesia was nearly the same as that of epinephrine.