EFFECTS OF PULSATILE AND NONPULSATILE PERFUSION MODE DURING EXTRACORPOREAL-CIRCULATION - A COMPARATIVE CLINICAL-STUDY

In a prospective randomized study with 80 male patients scheduled for aorto-coronary bypass grafting we investigated the influence of pulsatile and nonpulsatile perfusion mode on cell count (leukocytes, platelets, hematocrit), concentrations of thromboxane (TXB2), 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha), plasma hemoglobin, PMN-elastase, complement C3a, clotting factor XII, lactate, plasmatic inhibitors (C1-INH, AT-III, alpha2-antiplasmin), arterio-venous oxygen difference (AVDO2) and hemodynamic parameters. Changes in hematocrit were similar in both groups, whereas plasma hemoglobin concentration was significantly higher with pulsatile perfusion. Platelet count paralleled changes in hematocrit and was not influenced by the perfusion mode. Leukocyte count as well as concentrations of PMN-elastase and C3a showed a strong increase during cardiopulmonary bypass, but there were no significant differences between the two groups. Similar changes of the concentrations of TXB2 and 6-keto-PGF1alpha were noted irrespective of the perfusion mode applied. The observed alterations in the concentrations of clotting factor XII, alpha2-antiplasmin, AT-III and C1-INH largely paralleled hematocrit changes in either flow mode. Significant differences between the two groups were found with lactate: with nonpulsatile perfusion there was a slight but continuous increase, while with pulsatile flow lactate levels remained unchanged. There was no evidence for a better oxygen uptake (AVD(O2)) with pulsatile perfusion. Pulsatile perfusion seems to be advantageous to tissue perfusion, however, at the cost of a higher rate of hemolysis. We cannot confirm further salutary effects of the pulsatile perfusion mode with the 1-pump-system on cellular and humoral blood constituents. Therefore, we do not consider the use of the technically more sophisticated pulsatile flow mode superior to nonpulsatile perfusion in routine cardiac surgery.