Heparin-level-based anticoagulation management during cardiopulmonary bypass: a pilot investigation on the effects of a half-dose aprotinin protocol on postoperative blood loss and hemostatic activation and inflammatory response.

Koster et al describe the use of a half-dose aprotinin protocol and the influence on postoperative blood loss. The second endpoint of this investigation was a bunch of several hemostatic and inflammatory markers. The authors claim to apply a new heparin-level-based anticoagulation management.

Not surprisingly, the authors found a significant reduction of postop bleeding tendency. This message is not really new since several previous authors demonstrated this result with either full-dose, half-dose, or pump-prime-only dosage. In my opinion, at present, we dont need any longer efficacy studies about aprotinin. This is already done. What we need is studies defining the most efficacious dose of aprotinin, because we have conflicting results about this topic.

The paper gives no information about the possible advantage of the applied anticoagulation management since no data of heparin levels or heparinization are provided.

Additionally, the authors measured a variety of hemostatic and inflammatory markers pre- and post CPB. This is a multi-shot approach without a clear-stated hypothesis. As expected, some of these variables demonstrated differences between aprotinin and control. Nothing new, that the D-Dimers werde reduced with aprotinin. It is well known that infammatory markers peak 4 to 7 hours postoperatively. The present study did not measure at these time points. Therefore, it cannot give conclusive information about possible antiinflammatory properties of aprotinin.

In reference to inflammation or hemostasis, the paper presents only limited information. The message is, aprotinin reduces blood loss, is apparently safe and more studies are needed to define the precise influence of aprotinin on hemostasis and inflammation.

– Wulf Dietrich