Association between postoperative hypothermia and adverse outcome after coronary artery bypass surgery

Background. We examined the effect on outcome of mild hypothermia (< 36°C) upon intensive care unit (ICU) admission on patient outcome after coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). Methods. We performed a retrospective database analysis of 5,701 isolated CABG patients requiring CPB, operated upon from January 1995 to June 1997. Patients were classified as either hypo- (< 36°C) or normothermic (≥ 36°C) upon ICU admission. ICU admission bladder core temperature (BCT) versus outcome was evaluated. Outcome measures included mortality, resource utilization (mechanical ventilation time, ICU and hospital length of stay, and postoperative packed red blood cell transfusion), and major morbidity (cardiac, renal, neurologic, or major infection). Results. Overall, patients admitted to the ICU with BCT < 36°C had a significantly greater mortality (p = 0.02), prolonged mechanical ventilation (p = 0.007), packed red blood cell transfusion (p = 0.001), ICU (p = 0.01), and hospital (p = 0.005) length of stay. Conclusions. BCT of less than 36°C, upon ICU admission, has a significant association with adverse outcome after CABG with CPB.