Heated humidification in major abdominal surgery

The influence of heated humidification on body temperature and postoperative shivering was studied in 30 patients undergoing major intra-abdominal surgery. In the control group (I) the anaesthetic gases, administered in a non-rebreathing system, were humidified by a sponge heat and moisture exchanger. In group II the gases were humidified and heated to 37 degrees C and in group III up to 40 degrees C. Anaesthesia, surface insulation and warming of the infusions were standardized. The temperature was registered at the lower oesophagus and the big toe. Shivering and the feeling of cold were estimated at 15 min intervals postoperatively. A good correlation was found between heat gain during the first hour of recovery, the feeling of cold and intensity of shivering. Intraoperative heat loss was minimal in all groups. Heated humidification had no statistically significant effect on the body temperatures or postoperative shivering and thus provided no additional advantage compared to the control group.