STUDY OF BASIC PHYSIOLOGIC CHANGES ASSOCIATED WITH HYPOTHERMIA

Abstract

THE SEARCH for a method which would permit intracardiac surgery under direct vision has focused attention on induced hypothermia by surface cooling as a means to this end. Bigelow first demonstrated that significant reduction of oxygen consumption of the tissues occurred as a result of lowering body temperature and that during profound hypothermia the circulation could be interrupted for as long as 15 minutes.* Confirmation of these observations has come from additional experiments on animals and from clinical experience with hypothermia during surgery of the heart and great vessels.† However, the relatively high incidence of ventricular fibrillation and death in dogs at body temperatures below 28 C. poses a real hazard for practical application to clinical surgery. Furthermore, little is known of acid-base balance and metabolic behavior in mammals in the hypothermic state, and the few studies which have been made are in disagreement.‡ The studies presented in this paper