Methods: This randomized, controlled and prospectively designed study included two independent groups, consisting of 27 nonpulsatile (NP) and 24 pulsatile (P) cases who had undergone open heart surgical procedures. Demographic and hemodynamic data were recorded. The effects of perfusion types were evaluated in terms of free hemoglobin (free Hb), haptoglobin (Hp), lactate dehydrogenase (LDH), potassium (K+), platelet number (plt) and urine Hb. These levels were measured in preoperative period, 30 and 60 minutes after initiation of cardiopulmonary bypass (CPB), two and 24 hours postoperatively. Also, total chest drainage and transfusion requirement were assessed.

Results: Demographic and hemodynamic measurements did not differ between the groups. The mean arterial pressure of the NP group was statistically higher at the 30^th minute. Free Hb, Hp, LDH and K+ levels did not differ in both groups in all time points. The urine Hb levels were significantly higher in the P group in the 30^th minute. There was no difference regarding total chest drainage amounts and number of transfused erythrocyte cell packages.

Conclusion: A clinically nonsignificant hemolytic effect of pulsatile perfusion can be outlined, although it is mentioned only in the urine Hb measurements on the laboratory basis.