RESUMEN
Renal damage caused by hemolysis during cardiopulmonary bypass (CPB) was investigated, and the preventive effects of haptoglobin in regard to this condition was also evaluated. Nineteen patients who underwent open heart surgery were divided into two groups: a control group (<i>n</i>=11) and a haptoglobin group (<i>n</i>=8). In the control group, the level of plasma-free hemoglobin increased significantly after CPB (<i>p</i><0.01), and this level was strongly correlated with renal tubular leaking enzymes: NAG (<i>r</i>=0.76) and γ-GTP (<i>r</i>=0.81), in the Intensive Care Unit or on the first day after surgery. On the contrary, in the haptoglobin group, in which 4, 000 units of haptoglobin was added in the priming solution of CPB, no increased level of plasma free hemoglobin was observed. Furthermore, leak age of renal tubular enzymes were statistically less (<i>p</i><0.05). It was concluded that free hemoglobin was a cause of renal damage during CPB and the damage was preventable by the administration of haptoglobin.