Exposure to postoperative hypothermia and its association with complications after major abdominal surgery: a retrospective cohort study.

Purpose: Many patients who undergo major abdominal surgery experience inadvertent hypothermia during the perioperative period. This study aimed to identify risk factors related to postoperative hypothermia and their association with postoperative complications. Methods: This retrospective cohort study used data from Seoul National University Bundang Hospital, a tertiary university medical center in South Korea, between January 1, 2018 and December 31, 2022. We included patients aged ≥18 years who underwent elective major abdominal surgery for more than 2 hours in the operating room. The patients were categorized into the hypothermia (body temperature <36.5℃) and non-hypothermia (body temperature ≥36.5℃) groups. Results: The study sample comprised 30,194 patients, and we classified 21,293 and 8,901 into the hypothermic and non-hypothermic groups, respectively. Some factors associated with the occurrence of postoperative hypothermia included the type of surgery. In the multivariable logistic regression model, the incidence of postoperative complications was 9% higher in the hypothermia group than in the non-hypothermic group (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.01-1.19; P = 0.040). Among postoperative complications, the hypothermic group showed a 14% higher incidence of acute kidney injury (OR, 1.14; 95% CI, 1.04-1.25; P = 0.007) than the non-hypothermic group. Conclusion: The appearance of postoperative hypothermia during the first 30 minutes of the recovery period was significantly associated with the appearance of postoperative complications, especially acute kidney injury. However, further studies are required to validate these findings.