Influence of mechanical resistance of red cells on expressiveness of hemolysis after cardiopulmonary bypass

The study enrolled patients with ischemic heart disease with moderate (37 patients) and apparent hemolysis (18 patients) after coronary bypass surgery under cardiopulmonary bypass. Before and after the operation the concentration of free hemoglobin in blood plasma, mechanical resistance of red cells, content of TBA-active products and the general antioxidant activity in red cells were studied, while taking into account the artificial blood circulation activity and perfusion speed as well. It was established that among patients with apparent post-perfusion hemolysis the level of TBA-active products in red cells increased after surgery, while their general antioxidant activity tended to decrease. Development of moderate hemolysis is not accompanied by changes in the oxidant-antioxidant balance of red cells. There were no reliable differences in the duration of cardiopulmonary bypass, perfusion volume velocity, as well as mechanical resistance of red cells among the groups of patients at both levels of the study. Thus, individual-conditioned apparent post-perfusion hemolysis is based on a free-radical mechanism of red cell damage, and not on a mechanical trauma of blood cells when under cardiopulmonary bypass.