Early recognition of surgically correctable causes of excessive mediastinal bleeding after coronary artery bypass graft surgery.

In an attempt to establish criteria to enable recognition of patients with surgically correctable causes of excessive mediastinal bleeding, 250 patients undergoing coronary artery bypass graft surgery were reviewed. Ten (4 percent) required reexploration for excessive postoperative mediastinal bleeding and were compared with 95 consecutive control patients. There were no statistically significant differences in preoperative coagulation studies, use of aspirin or warfarin, number of vessels bypassed or bypass time. Mean mediastinal blood loss was statistically greater (p less than 0.001) in the reexploration group for the first 8 hours of the postoperative period than in the control group. Mean heterologous blood transfusion was 8.4 units in the reexploration group compared with 1.3 units in the control group. Based on analysis of the differences in mediastinal bleeding rates in the control and reexploration groups, we conclude that after coronary artery bypass graft surgery postoperative mediastinal bleeding of greater than 300 ml in the 1st hour, greater than 250 ml in the 2nd hours, and greater than 150 ml/hour thereafter suggests the presence of a surgically correctable lesion.