[The function of red blood cells under open-heart surgery with extracorporeal circulation without donor blood]

In 18 patients scheduled for open-heart surgery with extracorporeal circulation without donor blood, P50, 2, 3-DPG, intracellular sodium and potassium in red blood cells, and erythrocyte deformability were measured for the purpose of investigating the influence of severe hemodilution on oxygen transport and function of red cells. P50 and 2, 3-DPG in red cells showed no significant changes until the end of cardiopulmonary bypass (CPB). At the end of operation, 2, 3-DPG content decreased significantly without a significant change of P50. This is probably due to the rightward shift of oxyhemoglobin dissociation curve as compensation for the hemodilution without donor blood. On the first postoperative day, P50 value and 2,3-DPG content decreased significantly but returned to previous values on the second day. As the result of changes of red cell sodium contents and deformability, erythrocyte morphology recovered soon after the end of CPB, but the membrane function of red cells was restored a few days later. In conclusion, oxygen transport in red cells may be disturbed after open-heart surgery with extracorporeal circulation without donor blood.