PERIOPERATIVE MAINTENANCE OF NORMOTHERMIA REDUCES THE INCIDENCE OF MORBID CARDIAC EVENTS - A RANDOMIZED CLINICAL-TRIAL

Objective.-To assess the relationship between body temperature and car diac morbidity during the perioperative period. Design.-Randomized con trolled trial comparing routine thermal care (hypothermic group) to ad ditional supplemental warming care (normothermic group). Setting.-Oper ating rooms and surgical intensive care unit at an academic medical ce nter. Subjects.-Three hundred patients undergoing abdominal, thoracic, or vascular surgical procedures who either had documented coronary ar tery disease or were at high risk for coronary disease. Outcome Measur e. The relative risk of a morbid cardiac event (unstable angina/ischem ia, cardiac arrest, or myocardial infarction) according to thermal tre atment. Cardiac outcomes were assessed in a double-blind fashion. Resu lts.-Mean core temperature after surgery was lower in the hypothermic group (35.4+/-0.1 degrees C) than in the normothermic group (36.7+/-0. 1 degrees C) (P<.001) and remained lower during the early postoperativ e period, Perioperative morbid cardiac events occurred less frequently in the normothermic group than in the hypothermic group (1.4% vs 6.3% ; P=.02). Hypothermia was an independent predictor of morbid cardiac e vents by multivariate analysis (relative risk, 2.2; 95% confidence int erval, 1.1-4.7; P=.04), indicating a 55% reduction in risk when normot hermia was maintained. Postoperative ventricular tachycardia also occu rred less frequently in the normothermic group than in the hypothermic group (2.4% vs 7.9%; P=.04). Conclusion.-In patients with cardiac ris k factors who are undergoing noncardiac surgery, the perioperative mai ntenance of normothermia is associated with a reduced incidence of mor bid cardiac events and ventricular tachycardia.