Temperature Measurement in Patients Undergoing Colorectal Surgery and Gynecology Surgery: A Comparison of Esophageal Core, Temporal Artery, and Oral Methods

Maintaining perioperative normothermia reduces postoperative complications. An accurate, noninvasive method to take temperatures representative of core temperature is needed. Oral thermometry is accepted as the most accurate means of non-core temperature assessment, but poses challenges in patients who are intubated or wearing oxygen masks. The purpose of this study was to determine the difference, if any, between core temperature as measured by an esophageal thermometer and temperatures measured by oral and temporal artery methods in patients undergoing colorectal or gynecology surgery. A repeated-measures design was used with a convenience sample of 23 patients undergoing colorectal or gynecology surgery. Two series of intraoperative temperatures were taken (oral and temporal artery thermometry) and compared with core temperature measured by esophageal probe. Repeated-measures analysis of variance tested for biases of oral or temporal temperatures versus core temperatures. Bland-Altman plots were drawn to test dependence of bias on actual core temperature. A priori, a temperature difference >0.4° C was defined as clinically significant. Oral temperature was biased high relative to esophageal temperature by 0.12° C on average (P = .0008; 95% confidence interval [0.061, 0.187]). Temporal artery temperature was biased high relative to esophageal, by 0.074° C on average (P = .03; 95% confidence interval [0.010, 0.133]). Differences between core (esophageal) thermometry and oral or temporal artery thermometry were statistically significant but much smaller than the 0.4° C identified as clinically acceptable. Oral and temporal artery temperatures are within the 0.4° C of core (esophageal) temperatures, a difference that is considered clinically acceptable. Temperatures taken orally or by temporal artery thermometry are acceptable as noninvasive core measures for adult patients undergoing colorectal or gynecology surgery.