Unplanned perioperative hypothermia and agreement between oral, temporal artery, and bladder temperatures in adult major surgery patients

Accurate body core temperature measurement is essential in perioperative areas to quickly recognize and address abnormal temperatures. The purposes of this prospective, descriptive study were to accurately identify unplanned perioperative hypothermia (UPH) in 64 elective major surgery patients; to describe factors that increased the risk of UPH; to describe active/passive warming measures; to describe thermal comfort in patients with and without UPH; and to compare oral, temporal artery, and bladder temperatures. Based on bladder temperatures, 52% of the patients had UPH in the operating room (OR) and 42% on postanesthesia care unit (PACU) admission. The temporal artery thermometer did not detect any hypothermia. Descriptive data and Bland-Altman plots showed lack of agreement between the temporal artery thermometer readings and those of the oral and bladder thermometers. The patient's thermal comfort report did not accurately reflect hypothermia. Factors found to increase the risk of UPH included older age, BMI lower than 30, and OR ambient temperature lower than 68°F. All but one patient had active warming in the OR; active warming was infrequently used in the PACU. Based on our findings and findings in previous studies, we do not recommend using the temporal artery thermometer in perioperative areas. To prevent UPH, we recommend aggressive use of convective and conductive warming measures in perioperative areas and increasing OR ambient temperatures.