Mediastinal drainage blood. Potentialities for autotransfusion after cardiac surgery

The rate of postoperative bleeding was studied in 32 patients with aortocoronary bypass surgery and in 18 with aortic valve replacement. In 12 of the 50 patients, more than 500 ml of shed mediastinal blood could be saved within 8 postoperative hours. Aerobic and anaerobic cultures of such blood were obtained from the suction reservoir in 20 cases 2, 4 and 6 hours postoperatively. The results were negative, apart from Staphylococcus albus in one 6-hour sample. The blood, which was in some degree hemolyzed, contained acceptable amounts of red cells and albumin. Alterations of the coagulation and fibrinolytic systems indicated massive proteolysis with degradation of the proteins to an extent that precluded coagulation. This proteolysis had taken place in the mediastinum, resulting in total defibrinogenation of the blood. The authors conclude that in about one-fourth of cases in cardiac surgery, postoperatively shed blood is worth saving for red cell and volume substitution.