"Keeping Them Warm"-A Randomized Controlled Trial of Two Passive Perioperative Warming Methods.

PURPOSE Inadvertent perioperative hypothermia is a common problem for patients undergoing surgery. Heat redistribution from the body's core to the periphery after induction of anesthesia is the major contributor. DESIGN A prospective randomized controlled trial was conducted to determine if reflective blankets are more effective than cotton blankets in reducing the core-peripheral temperature gradient and increasing peripheral compartment heat content during the preoperative phase among adult patients undergoing elective surgery of less than 1 hour. About 328 adult patients undergoing general anesthesia were randomly allocated into two groups. METHODS Data were analyzed using independent t tests for continuous variables and chi-square tests for categorical variables. FINDINGS There was a significantly smaller reduction in temporal artery/foot temperature gradient (1.13 vs 1.64°C, P < .001) and a significant increase in foot temperature (0.64 vs 0.11°C, P < .001) in the reflective blanket group. CONCLUSIONS Reflective blankets are more effective than cotton blankets in warming patients' periphery and reducing core-peripheral temperature gradient preoperatively. AUSTRALIAN NEW ZEALAND CLINICAL TRIALS REGISTRY NUMBER ACTRN12614000931673 (retrospective registration).