Physiological studies during hypothermia in monkeys

Abstract

Rhesus monkeys were subjected to hypothermia (20°C) after initial, light anesthesia. Heart rate, EEG and minute volumes during spontaneous respiration were recorded. With cooling there was a progressive fall in heart rate, respiratory rate and minute volume unrelated to the type of anesthetic agent (quantitatively administered ether or i.v. pentobarbitone). Spontaneous EEG waves disappeared at 23°C following initial anesthesia with pentobarbitone, but persisted to 19°C after ether anesthesia. Bemegride injected into the hypothermic monkeys caused activation of the EEG. It is concluded that similar procedures could be applied with safety to human subjects for psychiatric purposes. Submitted on August 28, 1959