Aprotinin was withdrawn from the market because of safety issues in 2007. This retrospective study compares blood loss and transfusion requirements before and after the withdrawal of aprotinin. Contrary to custom, the institution used a combination of low-dose aprotinin and relatively low-dose tranexamic acid (2 g) given after protamine (n = 615). This regimen was compared to the use of tranexamic acid alone (n = 587). The authors found an increase in bleeding and transfusion requirement in patients not treated with aprotinin. Interestingly, the rate of rethoracotomy increased from 5.5% to 9.0% in the tranexamic-alone group. This study is subject to all drawbacks of retrospective and observational studies. Additionally, the drug dosage in both groups was quite unusual. However, this study also demonstrates that the withdrawal of aprotinin constitutes a challenge for blood conservation in cardiac surgery and much work is to be done to define the most effective dosage of tranexamic acid or other alternatives to aprotinin.

– Wulf Dietrich