Temperature Changes During Anesthesia and Operations

IT IS KNOWN that changes in body temperature occur during surgical operations with the patient under general anesthesia. Early investigations¹⁻³demonstrated that the body temperature frequently fell by 0.5 to 1.5 C; reasons suggested for this finding were loss of body heat by radiation in cold operating rooms,¹,⁴decrease in cellular oxidation,⁵cutaneous vasodilation, and decreased muscular activity.⁶It soon became apparent that hyperpyrexia could also occur during operations and in the immediate postoperative period.⁷Moschcowitz in 1916⁸and Cutting in 1931,⁹in a review of the literature, attributed hyperpyrexia during anesthesia to high ambient temperature and humidity frequently observed in operating rooms before the advent of air-conditioning. However, in the study by Clark and Orkin in 1954¹⁰patients showed a rise in body temperature at all ambient temperatures including those as low as 14.5 to 18 C (58 to 64 F). The