Prevention of intraoperative hypothermia during abdominal surgery.

Heat balance and core and skin temperatures were studied in 111 patients during abdominal surgery. In minor surgical procedures the effects of heating of inspired humidified gases (n = 23) and of a heating mattress (n = 21) were compared with the conditions in an unwarmed control group (n = 24). These two methods were about equally effective in preserving total body heat, although the major effect of the heating mattress was to conserve heat which had been redistributed to the surface, and such heat could subsequently be lost to the environment. During major abdominal surgery 18 unwarmed control patients were compared with patients (n = 25) provided with a heat supply. The combined measures of heated humidified inspired gases, a heating mattress, insulation by a heat-reflecting blanket, warming of all infusions and transfusions and a warm operating room were all needed to balance the great heat losses during the major surgical procedures. With such massive heat supply it was possible to prevent heat loss and a fall in core temperature.