Marc Janssens

High-dose aprotinin reduces blood loss in patients undergoing total hip replacement surgery

BackgroundAprotinin, a proteinase inhibitor, has been reported to reduce blood loss significantly during cardiac surgery. The mechanisms of this effect remain unclear. We studied the effect of aprotinin on blood loss and transfusion requirement during total hip replacement. Potential mechanisms of action and side effects also were investigated. MethodsForty patients scheduled for primary total hip replacement were randomized to receive, in double-blind fashion, either aprotinin given as a bolus of 2 X 104 kallikrein inactivator units (KIU) followed by an infusion of 5 X 105 KIU/h until the end of surgery or an equivalent volume of normal saline. Anesthesia and surgical techniques were standardized and systematic deep venous thrombosis prophylaxis was used. Peri- and postoperative blood loss and transfusion were measured. Fibrinolysis, coagulation pathways, and platelet function were assessed. Renal and hepatic function as well as the incidence of deep venous thrombosis also were assessed. ResultsAprotinin reduced total blood loss from 1,943 ± 700 ml to 1,446 ± 514 ml (P < 0.05). This reduction of blood loss occurred during surgery (P < 0.05) and postoperatively (P < 0.001). Total amounts of blood transfused were 3.4 ± 1.3 units/patient in the control group and 1.8 ± 1.2 units/patient in the aprotinin group (P < 0.001). The activated partial thromboplastin time was significantly prolonged by aprotinin immediately after surgery, at 50.6 ± 12.4 versus 32.3 ± 4.6 s in control patients (P < 0.001), but results of the other coagulation tests were not different between the two groups. No side effects were observed in the aprotinin group. The incidence of deep venous thrombosis in the two groups was not significantly different. ConclusionsThe use of high-dose aprotinin during total hip replacement results in a reduction in both blood loss and the amount of blood transfused. Aprotinins mode of action, however, remains to be elucidated.

Treatment of Excessive Mediastinal Bleeding After Cardiopulmonary Bypass

BACKGROUND Excessive mediastinal bleeding after cardiopulmonary bypass is one of the most frequently reported complications of cardiac operations. Appropriate treatment requires a rapid and effective diagnostic work-up, based on the knowledge of the pathophysiology induced by cardiopulmonary bypass. METHODS Possible causes, diagnostic methods available, and therapeutic approaches are reviewed in the light of the literature published on excessive bleeding after cardiac operations. RESULTS When bleeding is massive (> 250 to 300 mL/h for the first 2 hours, > 150 mL/h thereafter), immediate surgical reexploration is mandatory. When bleeding is less important (50 to 150 mL/h), the decision to reoperate should be based on the presence of hemodynamic compromise or a suspected surgical cause. Otherwise, coagulation testing should allow the correction of hemostatic defects as appropriate with protamine, platelet concentrates, fresh frozen plasma, desmopressin, or antifibrinolytics. Hypothermia and hypotension should be corrected and a trial of positive end-expiratory pressure may be considered if diffuse mediastinal oozing (especially from the bed of the mammary artery) is suspected. CONCLUSIONS A protocol is suggested to guide treatment, taking into account the rapidity of blood loss and the suspected underlying cause.