Hyperthermia and halothane MAC in the dog

Abstract

To evaluate the effect of hyperthermia on anesthetic requirement, the changes in minimum alveolar concentration (MAC) of halothane which accompanied increases in esophageal temperatures from 37.3 to 45.9C were determined in 8 spontaneously breathing dogs. MAC increased linearly by 27% as temperature rose to 40.7C (i.e., 8% per degree C). At temperatures above 42C MAC decreased. Death occurred at a mean temperature of 45.9C.