Mild hypothermia has long been a well-known accompaniment of anesthesia and surgery. General anesthetic agents inhibit normal thermoregulatory control so that a reduction in core body temperature of 1°C to 2°C is expected in patients anesthetized for 1 to 2 hours or more. This effect is compounded during prolonged operations, especially those in which thoracic and abdominal cavities are exposed to ambient air. Another factor contributing to intraoperative hypothermia is the intravenous administration of cold (blood) or room temperature fluids. Mild hypothermia (35°C) has been accepted as an inevitable consequence of general anesthesia and surgery.
See also p 1127.
In this issue of JAMA, Frank et al1 report an association between mild intraoperative hypothermia and postoperative morbid cardiac events. They prospectively studied 300 patients older than 60 years, undergoing abdominal, thoracic, or peripheral vascular surgical procedures who had documented coronary artery disease or were at high risk for coronary
Cheney FW. Should Normothermia Be Maintained During Major Surgery?. JAMA. 1997;277(14):1165-1166. doi:10.1001/jama.1997.03540380079036