[Use of high doses of aprotinin in cardiac surgery]

To study the efficacy of aprotinin in reducing whole blood loss after cardiac surgery with extracorporeal circulation.

Two groups of patients undergoing cardiac surgery with extracorporeal circulation were studied. Group I (n = 51) received 2 x 10(6) KIU (kallikrein inhibiting units) of aprotinin upon anesthetic induction, a similar dose in the extracorporeal circulation priming pump, and a maintenance dose of 500,000 KIU/h until removal from the operating theater. Group II (n = 51) was the control group. Patients that had previously undergone surgery with extracorporeal circulation were excluded, as were those being treated with anti-coagulants or anti-aggregants. Data recorded were blood volume, transfusions needed in the first 24 h, and blood derivatives used throughout the hospital stay. Postoperative kidney function was also determined. The occurrence of acute myocardial infarction in patients undergoing myocardial revascularization was also noted.

Group I required a mean of 2.40 U of concentrated red blood per patient during the first postoperative day, as opposed to a mean of 4.3 U in group II (p < 0.001). Blood loss through drains was also less in group I than in group II (431.82 vs 895.29 ml; p < 0.001). Total blood needed during the hospital stay was 3.50 units per patient in group I vs 5.40 U in group II (p < 0.001). Urea and creatinine were similar in the two groups before and after surgery (p = NS), and there were no significant differences in the number of cases of acute myocardial infarction in the two groups (3 in group I and 2 in group II).

Administration of high doses of aprotinin is an effective technique for reducing the need for whole blood in patients requiring extracorporeal circulation during surgery. The technique does not compromise kidney function or increase the risk of perioperative acute myocardial infarction.