High Preoperative Anxiety Level and the Risk of Intraoperative Hypothermia

Aim: The relationship between preoperative anxiety level and intraoperative hypothermia (<36℃) was investigated. Background: Core temperature often decreases during surgery, with an initial rapid decrease followed by a slower decrease for about 2 hours. Preoperative anxiety may influence perioperative physiological responses. The relationship between preoperative anxiety level and perioperative decrease in core temperature has not been studied closely. Design: A prospective observational study. Methods: This study enrolled 120 adult patients who underwent elective major abdominal surgery under combined epidural and general anesthesia. Tympanic membrane temperature was used to measure core temperature preoperatively and during the operation. The relationship between anxiety level according to the State-Trait Anxiety Inventory (STAI) and core temperature was examined using descriptive and multivariate risk analysis. Results: High anxiety level was found in 61 patients (51%), of which 26 (43%) developed hypothermia during the first hour and 40 (66%) developed hypothermia during the first 2 hours of anesthesia. After adjustment for covariates, patients with a high anxiety level were found to have a 2.17-fold higher risk of hypothermia during the first hour and a 1.77-fold higher risk of hypothermia during the first 2 hours than patients with a low/moderate anxiety level. Conclusions: The risk of hypothermia in the early phase of general anesthesia can be predicted by measurement of the preoperative anxiety level using the STAI. Relevance to Clinical Practice: Patients with a high anxiety level had a significantly higher risk of intraoperative hypothermia. Preoperative preventive nursing care programs should include anxiety management and thermal care.