Resistive Warming Mattress, Forced-Air Warming System, or a Combination of the Two in the Prevention of Intraoperative Inadvertent Hypothermia: A Randomized Trial

Abstract

To prevent intraoperative inadvertent hypothermia (IIH), resistive products and forced-air warming systems are often used simultaneously. There is insufficient evidence to show whether this application is clinically more effective than a single active warming device. The aim of this study is to compare the efficacy a single intraoperative active warming method with combined methods in IIH prevention. A randomized, prospective, experimental study. This study was conducted between June and October 2021 in the operating room of a training and research hospital. The study sample consisted of 123 patients who underwent scheduled orthopedic surgery under spinal anesthesia, were young (18-64), and had an ASA risk score of I to III. The patients were divided into three groups preoperatively according to the stratified randomization technique. To prevent IIH, a resistive warming mattress was used in group 1; a forced-air warming system was used in group 2; and a combination of the two methods were used in group 3. The body temperatures of the patients were measured and recorded every 15 minutes from admission to the operating room until the end of surgery. The mean intraoperative body temperature of the patients was 36.6±0.15˚C for group 1; 36.6±0.1˚C for Group 2 and 36.6 ± 0.15˚C for Group 3. There was no difference between the groups in terms of body temperature. The overall incidence of IIH was 8.1%; 9.8% in group 1, 9.8% in group 2 and 4.9% in group 3. There was no statistically significant difference between the groups in terms of IIH (p < .05). This study supports the efficacy of using resistive warming mattress and forced-air warming systems in preventing IIH. The use of both methods together made no difference in terms of IIH development.