Comments on Presentations

we shou!d purcue too far the attempt to standardize perfusates, equipment, or technics. I might have a slightly different opinion about surgical bleeding than Dr. Maloney. I believe that every patient on cardiopulmonary bypass has a bleeding tendency. Thus, I am very hesitant to accept any changes in the perfusate that involve some compromise in terms of clotting factors. I estimate, from Dr. Maloney’s data, that in his series of cases the average amount of drainage from the chest in an adult is about 500 ml during the first 12 to 24 hours after operation. I do not consider this excessive. I agree that currently one has to reoperate only infrequently to control postoperative bleeding and that such bleeding is only rarely a cause of death. On the other hand, postoperative bleeding does frequently complicate the clinical course of patients. These patients do require transfusions in the postoperative period, and this adds to the total amount of blood required for cardiac surgery. I think that we need better methods for restoring the patient’s clotting mechanism to normal at the end of bypass. This area of investigation should be pursued. As advocated by Dr. Perkins, we titrate the patient’s blood for excess heparin or protamine about 30 minutes after we give the protamine. If there is an excess of heparin, we give more protamine. We think that this is a technical improvement, but cannot see that it has resulted in a marked decrease in the amount of postoperative bleeding. Some of our group, including me, use EACA as suggested by the group at Children’s Hospital in Boston. I begin its administration as soon as the sternum is cut, on the basis of the finding that fibrinolysins appear in the blood after any large bone is severely traumatized. We have an opportunity to compare the effects of EACA in our group because different surgeons are using technics that differ only in the omission or inclusion of the administration of EACA. I am disappointed to say that, on this comparative basis, its use does not affect the postoperative blood loss. We have also separated the platelets from freshly drawn ACD blood before it is put in the machine, held them, and given them back to the patient about an hour after the end of bypass. By so doing, one can bring the platelet count up to normal in nearly all patients, but we do not have very good evidence that the procedure reduces the postoperative chest drainage very much. In closing, I wish to leave one thought concerning the factors that influence survival in cardiac surgery. I think a great deal of what we have discussed, including the perfusates, machines, etc., does not constitute the central problem. I think the available evidence indicates that most if not all patients who die after open-heart surgery die of either a failure of cardiac performance or a failure of pulmonary performance. It is rarely anything else. There is a good deal of knowledge about cardiac and pulmonary performance, but we need to have a great deal more.