Warm heart surgery: a prospective comparison between normothermic and tepid temperature

Due to concerns about complications from normothermic core temperature during cardiopulmonary bypass, we initiated a prospective randomized study of 200 consecutive patients. In one group (group A), both the heart and the body temperature were kept at 37 degree C. In the second group (group B), both the body and myocardial temperature were allowed to drift down to 34 degree C. There were no differences between these two groups in age, sex, preoperative numbers of elective, urgent, emergent, redo patients, or coronary artery bypass (CAB), valve, CAB/valve procedures. Their preoperative neurological, pulmonary, renal, and vascular disease status were similar. Preoperative EF was 53% in group A (100 patients) and 52.5% in group B (100 patients). Group A required more volume (p = 0.001) and had less urine output (p = 0.03) during and post bypass. Group A required more phenylephrine hydrochloride (p = 0.05) and had more difficulty managing blood pressure. Strokes and renal failure necessitating dialysis occurred more often in group A but without statistical significance. More difficulties occurred in the normothermic (37 degrees C) group and cardioprotective effects of warm heart surgery may remain intact at 34 degrees C. Mild "drifted/tepid" hypothermic heart surgery could be a better and safer procedure.