Accuracy of Temporal Artery Thermometry as an Indicator of Core Body Temperature in Patients Receiving General Anesthesia

Purpose: To evaluate the agreement of temporal artery temperature (Tat) with esophageal temperature (Tes) and oral temperature (Tor), and explore potential factors associated with the level of agreement between the thermometry methods in different clinical settings. Design: A prospective repeated measures (induction, emergence, and postanesthesia care unit) design was used. Methods: Temperature data were collected for 54 patients receiving general anesthesia. Analyses included descriptive statistics, paired t tests for the within-patient comparison of temperature methods, Bland-Altman plots to examine agreement between methods, and multiple linear regression to identify factors associated with the agreement between methods. Findings: Tat was significantly higher compared with Tes and Tor (P < .05) and was poor at detecting hypothermia. The use of a muscle relaxant and surgical site were suggested to be associated with the difference between Tat and Tes at emergence. Conclusions: Tat is more convenient, but less accurate, than other thermometry methods. These inaccuracies are exacerbated by common anesthetic medications.