Efficacy of a novel prewarming system in the prevention of perioperative hypothermia. A prospective, randomized, multicenter study

Abstract

Background: Perioperative hypothermia is a common complication during general anesthesia. Although rewarming of patients before surgery has been used as a preventive measure and some guidelines recommend it, the implementation of prewarming for every surgical patient is cumbersome. Therefore, we sought to determine the efficacy of two novel prewarming methods that could facilitate prewarming in daily practice.

Methods: This was a prospective, randomized, multi-center, controlled study. After IRB approval and informed consent, 90 patients undergoing surgery of 30-120 min duration with general anesthesia were randomly assigned to three groups: 1) standard preoperative insulation (Group A); 2) passive preoperative insulation with a commercial prewarming suit (Group B); 3) active preoperative prewarming with a forced-air warmer connected to a prewarming suit (Group C). All patients received warmed IV fluids and intraoperative forced air warming after induction of anesthesia. Oral temperatures were recorded in the preoperative and postoperative periods. Intraoperative core temperatures were measured with an esophageal probe.

Results: Repeated-measures analysis of variance (ANOVA) and post hoc Scheffé's test identified a significantly higher core temperature in the actively prewarmed group (Group C) compared to both passive groups (A, B) at 15, 30, 45, 60, and 75 min (P<0.05) after induction of anesthesia and at the end of surgery. During the first 30 min after admission at PACU, also higher oral temperatures were measured in Group C, compared with both passive insulation groups.

Conclusion: In our study active prewarming with a forced-air warmer and an insulating prewarming suit achieves significantly higher core temperatures during anesthesia and at the end of surgery and avoids hypothermia at the end of surgery compared to commercial or conventional insulation techniques.