Heated wire humidification circuit attenuates the decrease of core temperature during general anesthesia in patients undergoing arthroscopic hip surgery

Background: Intraoperative hypothermia is common in patients undergoing general anesthesia during arthroscopic hip surgery. In the present study, we assessed the effect of heating and humidifying the airway with a heated wire humidification circuit (HHC) to attenuate the decrease of core temperature and prevent hypothermia in patients undergoing arthroscopic hip surgery under general anesthesia. Methods: Fifty-six patients scheduled for arthroscopic hip surgery were randomly assigned to either a control group using a breathing circuit connected with a heat and moisture exchanger (HME) (n = 28) or an HHC group using a heated wire humidification circuit (n = 28). The decrease in core temperature was measured from anesthetic induction and every 15 minutes thereafter using an esophageal stethoscope. Results: Decrease in core temperature from anesthetic induction to 120 minutes after induction was lower in the HHC group (-0.60 +/- 0.27 degrees C) compared to the control group (-0.86 +/- 0.29 degrees C) (P = 0.001). However, there was no statistically significant difference in the incidence of intraoperative hypothermia or the incidence of shivering in the postanesthetic care unit. Conclusions: The use of HHC may be considered as a method to attenuate intraoperative decrease in core temperature during arthroscopic hip surgery performed under general anesthesia and exceeding 2 hours in duration.