Relative efficiency of two warming devices during laparoscopic cholecystectomy

Intraoperative hypothermia is a known consequence of general anaesthesia. Forced air warming devices are commonly used to prevent hypothermia in anaesthesia, but there are limited data on the use of radiant warming devices. Previous trials comparing the efficacy of forced air and radiant warming devices have reported discordant results. The current study evaluated the efficacy of these devices during elective laparoscopic cholecystectomy, where surgery was expected to last > 60 minutes. Twenty-nine patients were randomised to either a forced air warming device (Warm-touch; group 1, n = 15) or a radiant warming device applied to the face (Sun-touch; group 2, n = 14). All fluids were given via a standardised fluid warmer set at 41 degrees C. Oesophageal temperature was measured every 15 minutes until the end of the procedure. Between-group, over-time temperatures and interaction were analysed using a linear mixed model. Statistical significance was ascribed at P < or = 0.05. The median (range) time of surgery was 90 (60 to 180) minutes. Mean (SD) oesophageal temperatures in the Warm-touch and Sun-touch groups were at 15 minutes 36.2 (0.30) degrees C and 36.2 (0.57) degrees C, and at 90 minutes 36.2 (0.44) degrees C and 35.9 (0.29) degrees C respectively. There was no statistically significant temperature difference between groups (P = 0.69) or over time (P = 0.61), and no interaction between time and treatment group (P = 0.97). Postoperative headache was recorded in four Sun-touch and no Warm-touch patients (P = 0.04). No difference in the efficacy of the Sun-touch warming device compared with the Warm-touch was demonstrated. Operational-mode side-effects may limit the use of the Sun-touch device.