Accuracy of the Bair Hugger™ Core Body Temperature in Wrist Regions: Prospective Observational Study.

Abstract

Abstract Purpose: Monitoring body temperature is essential during perioperative period. Core body temperature requires invasive device that may cause complications. We aim to study accuracy of non-invasive Bair Hugger™ core body temperature monitoring system (BHTMS) at wrist compared to esophageal temperature under general anesthesia. Methods: Twenty adult patients of American Society of Anesthesiologists physical status I or II were enrolled in this study. BHTMS sensor was applied to wrist. After tracheal intubation, esophageal probe was inserted. Bair Hugger™ upper body warming blankets were applied. Esophageal temperature (Teso) and wrist temperature (Twrist) were recorded every 10 minutes. Results: Total 257 pairs of data set were analyzed and T_eso and T_wrist had statistically no significant difference (P = 0.103). Median of T_eso and T_wrist were 36.5℃ and 36.4℃. Bland-Altman analysis showed Teso - Twrist of 0.14℃ (2SD ± 1.44℃). Ninety-nine pairs of data set from 0 to 40 minute were analyzed and showed significant difference at 0, 10 minute (P < 0.001) and no significant difference at 20, 30, 40 minutes. Bland-Altman plot by times showed difference (Teso - Twrist) of 1.49℃, 0.82℃, 0.29℃, -0.03℃, -0.12℃ (2SD ± 2.00℃, ± 1.30℃, ± 1.32℃, ± 0.84℃, ± 0.82℃) at 0, 10, 20, 30, 40 minutes respectively. Conclusions: BHTMS at wrist area under upper body warm blanket may be another possible alternative method for monitoring core body temperature after 30 minutes compared to esophageal temperature. IRB number: 2112-030-489 (Date: 20220314) Clinical trial registration number: KTC0007211 (Date: 20220317)