General anesthesia for whole-body hyperthermia

General anesthesia was used to facilitate 259 whole-body hyperthermia treatments in 90 patients. These patients fell into American Society of Anesthesiologists Classifications 3 (moderate to severe systemic disease) and 4 (severe systemic disease with life-threatening potential). Whole-body hyperthermia imposes severe stress on cardiopulmonary and renal function. In this series, elevation of temperature from 38 degrees to 41.5 degrees raised cardiac output to approximately 200% of control, while oxygen consumption rose 35%. General anesthesia provides conditions which allow for more precise control and support of vital signs, fluid requirements, and blood gases.