Evidence of increased hemolysis after open heart surgery in patients heterozygous for Beta-thalassemia.

To investigate hemolysis after open heart surgery in patients with and without the beta-thalassemia trait, we prospectively studied 85 patients who underwent open heart surgery for various pathologic conditions. Hemoglobin electrophoresis showed that 20 of these patients had the beta-thalassemia trait, whereas the other 65 were normal. To compare the degree of postoperative hemolysis in both groups, we evaluated the serum bilirubin, lactic dehydrogenase, haptoglobin, and plasma hemoglobin levels preoperatively and on the first and second postoperative days. Patients with the beta-thalassemia trait had a significantly greater degree of hemolysis than did those without this trait. Hemolysis was more pronounced on the first postoperative day and was obviously caused by the passage of blood through the heart-lung machine. The degree of hemolysis was not affected by the patient's age or sex, or by the type and duration of the operation.