Reinfusion of mediastinal blood after heart surgery

Background: Several authors studying autotransfusion of shed mediastinal bl ood in patients undergoing heart operations have published conflicting resu lts regarding reduction of the need for homologous blood transfusion. The e ffect on coagulation parameters is also unclear. Methods: In a prospective randomized study, 198 patients who underwent coro nary artery bypass grafting or a valvular operation were divided into 2 gro ups: a group with autotransfusion of shed mediastinal blood after an operat ion and a control group. Continuous reinfusion of mediastinal blood was don e until no drainage was present or for a period of 12 hours after the opera tion. The amount of blood lost and autotransfused, the number of homologous blood products transfused, and the coagulation parameters were monitored. Results: The number of patients requiring homologous blood transfusion was significantly different between the 2 groups (54/98 [55%] in autotransfused patients vs 73/100 [73%] in the control group, P = .01). The number of ree xplorations for excessive bleeding was similar in the 2 groups (7/98 [7.1%] vs 8/100 [8%]), but the amount of blood collected postoperatively was high er in the autotransfused patients compared with control patients (1200 +/- 201 mt vs 758 +/- 152 mi,, P = .0007). Coagulation parameters analyzed and complication rates were similar in the 2 groups after the operations. Conclusion: Autotransfusion of shed mediastinal blood reduces the need for homologous blood transfusion inpatients undergoing various cardiac operatio ns. The cause of increased shed blood in patients undergoing autotransfusio n remains unclear.