Reduction of homologous blood requirement in cardiac surgery by intraoperative aprotinin application--clinical experience in 152 cardiac surgical patients.

The protease inhibitor aprotinin interacts with plasmin and kallikrein, which are generated in cardiac surgery during cardiopulmonary bypass (CPB). The influence of high-dose aprotinin application (2 million kallikrein inactivator units given i.v. at the beginning of anaesthesia followed by a 500,000 KIU/h infusion throughout the operation and additional 2 millions KIU added to the priming of the oxygenator) on perioperative blood loss and donor blood requirement was studied in 152 adult cardiac surgical patients. This group was compared to 317 patients having cardiac surgery without the application of aprotinin. Aprotinin reduced the homologous blood requirement by 43% (1783 +/- 100 vs 1015 +/- 131 ml, p less than 0.05), while the reduction of postoperative blood loss was 29% (1070 +/- 43 vs 761 +/- 51 ml, p less than 0.05). Fortytwo percent of the aprotinin treated patients completed their hospital stay without having any donor blood transfusion compared to 18% in the group without aprotinin. The blood saving effect was even more pronounced in operations with prolonged perfusion times. Intra- and postoperative complications were equally distributed in both groups. The blood-saving effect of aprotinin may be due to a platelet-preserving effect and/or kallikrein inhibition during CPB. There were no clinically relevant side effects related to aprotinin observed. It is concluded that high dose aprotinin therapy reduces both postoperative blood loss and homologous blood requirement, and therefore the routine application of aprotinin during cardiac surgical procedures is to be recommended.