Clinical evaluation of the oesophageal heat exchanger in the prevention of perioperative hypothermia.

We have studied the efficiency of an oesophageal warming device in the prevention of perioperative hypothermia in 22 patients undergoing total hip replacement. Aural canal and skin temperatures (15 sites) were measured before induction of anaesthesia, at the end of surgery and 1 h after recovery and mean body heat was calculated to quantify heat distribution. Core temperature decreased significantly in both groups at the end of surgery, by a mean of 1.8 degrees C in the control group and 1.3 degrees C in the oesophageal heat exchanger (treated) group (P = 0.09). In contrast, mean skin temperature at the end of surgery increased by a median value of 0.26 degrees C in the treated group and decreased by 1.02 degrees C in the control group (P = 0.03). Both groups of patients lost body heat to the same extent (P = 0.34). Thus the oesophageal heat exchanger was ineffective in preventing perioperative hypothermia in a group of patients undergoing total hip replacement.