[Haptoglobin determination in the serum of patients following intraoperative autotransfusion using the Haemonetics Cell Saver III. Studies on the loading of patients with free hemoglobin in retransfused erythrocyte concentrate].

In addition to hemodilution, mechanical intraoperative autotransfusion (IAT) is the most important method of preventing or minimizing the transfusion of homologous blood in operations with major blood loss. Most of the problems associated with IAT could be solved by the use of cell separators, but the separated red blood cells still contain an average of 200 mg/dl free hemoglobin. By the determination of haptoglobin levels before and after IAT, we studied the effects of free hemoglobin on the patient. Seventy-seven patients with hip-joint replacement were studied. In one group, n = 47, both intraoperative blood loss and drainage blood (for 6 h post-operatively) were collected and transfused back to the patient after cell separation with the Haemonetics Cell-Saver III as a red-cell concentrate. A second group, n = 34, received only homologous blood. Serum haptoglobin was determined after anesthesia induction and after the last transfusion on the day of operation. There were no significant differences in preoperative haptoglobin levels between both groups. In the IAT group, haptoglobin was significantly lower then in the control group after transfusion (t-test, P = 0.05). In both groups 14% of the patients' haptoglobin levels were pathologic preoperatively. Post-transfusion 60% of the IAT group showed minimum levels while in another 14% no haptoglobin could be measured. In these 14%, free hemoglobin was circulating in the patients' blood because the transport capacity was exhausted. In the control group only 26.5% of the haptoglobin levels were below normal and in no case was transport capacity exhausted (Table 3). The correlation between volume of retransfused autologous blood and decrease in haptoglobin level was small (r = 0.15). In a few cases with low volumes of retransfused blood the haptoglobin decrease may have been greater, so that free hemoglobin may have been present.