Covering the head and face maintains intraoperative core temperature

Abstract

Purpose: To determine the effect of covering the patient's head and face on the prevention of intraoperative hypothermia (< 35.5°C). Methods: This randomized, prospective trial included 44 adults undergoing elective abdominal surgery. After the induction of anesthesia with thiopental, in 44 patients their extremities and trunk were covered with towels and sheets. In addition, 22 patients (covered group) had their face and head fully covered. Anesthesia was maintained with N2O 50-66% (2-3 L · min-1) and isoflurane (< I MAC) in oxygen combined with thoracic epidural anesthesia. Core temperature was measured at the tympanic membrane continuously and was recorded at 15 min intervals from the induction of anesthesia. Heat and moisture exchangers were used in their anesthetic circuit. Ambient temperature was maintained near 25°C. Results: Neither group demonstrated intraoperative hypothermia. However, tympanic membrane temperature at 75, 90, 105 min in the covered group were higher than those of control group (36.7 ± 0.4°C vs 36.5 ± 0.4°C, 36.8 ± 0.5°C vs 36.4 ± 0.5°C, 36.8 ± 0.5°C vs 36.4 ± 0.5°C, respectively, P < 0.05). Conclusion: Covering the patient's head and face maintains intraoperative core temperature.