Adverse effects of hypothermia in postoperative patients.

The effect of intraoperative and postoperative temperature on morbidity, mortality, and other clinical risk factors was evaluated in 100 consecutive general surgical patients admitted postoperatively to a surgical intensive care unit. Hypothermia (temperature less than 97 degrees F) was present in 77 percent of the patients intraoperatively, in 53 percent at the end of surgery, and in 21 percent at 4 hours. Mortality was increased with patient age greater than 55 years, emergency surgery, operative blood pressure less than 100 mm Hg, operative fluid requirements greater than 1,500 ml/hour, temperature less than 97 degrees F at 2, 4, and 8 hours postoperatively, and presence of postoperative complications. Intraoperative fluid requirements were significantly greater for patients with mortality risk factors. Patients over 55 years of age were more often hypotensive and hypothermic than younger patients, but mortality was increased only for patients less than 55 years of age with a temperature of less than 97 degrees F at 8 hours or an operative blood pressure of less than 100 mm Hg. Mortality after general surgical procedures is increased with operative hypotensive and prolonged postoperative hypothermia. Hypothermic patients with mortality risk factors should be aggressively rewarmed postoperatively.