Core temperatures during major abdominal surgery in patients warmed with new circulating-water garment, forced-air warming, or carbon-fiber resistive-heating system

Abstract

Purpose: It has been reported that recently developed circulating-water garments transfer more heat than a forced-air warming system. The authors evaluated the hypothesis that circulating-water leg wraps combined with a water mattress better maintain intraoperative core temperature ≥36°C than either forced-air warming or carbon-fiber resistive heating during major abdominal surgery.

Methods: Thirty-six patients undergoing open abdominal surgery were randomly assigned to warming with: (1) circulating-water leg wraps combined with a full-length circulating-water mattress set at 42°C, (2) a lower-body forced-air cover set on high (≈43°C), and (3) a carbon-fiber resistive-heating cover set at 42°C. Patients were anesthetized with general anesthesia combined with continuous epidural analgesia. The primary outcome was intraoperative tympanic-membrane temperature ≥36°C.

Results: In the 2 h after anesthesia induction, core temperature decreased 1.0 ± 0.5°C in the forced-air group, 0.9 ± 0.2°C in the carbon-fiber group, and 0.4 ± 0.4°C in the circulating-water leg wraps and mattress group (P < 0.05 vs. forced-air and carbon-fiber heating). At the end of surgery, core temperature was 0.2 ± 0.7°C above preoperative values in the circulating-water group but remained 0.6 ± 0.9°C less in the forced-air and 0.6 ± 0.4°C less in the carbon-fiber groups (P < 0.05 vs. carbon fiber).

Conclusions: The combination of circulating-water leg wraps and a mattress better maintain intraoperative core temperature than did forced-air and carbon-fiber warming systems.

Fig. 1

Core temperature as a function of time in patients assigned to the circulating-water, forced-air, and carbon-fiber warming groups. All groups comprised 12 patients, except for at 150 min, when the forced-air group had 11. Temperature changes in the circulating-water group differed significantly from the other groups after 120 min. Temperatures in forced-air and resistive-heating groups never differed significantly. Results are presented as mean ± standard deviation (SD). ^#Significant difference versus forced-air group, *significant difference versus carbon-fiber group; P = 0.05. Core temperature at the end of surgery was 36.9 ± 0.7°C (circulating-water group), 36.2 ± 0.9°C (forced-air group), and 36.0 ± 0.6°C (carbon-fiber group)