A novel approach to anticoagulation control.

Heparin used in extracorporeal therapy often leads to bleeding complications. Protamine used for heparin reversal can cause adverse hemodynamic responses. To control both types of complications, a cellulosic hollow-fiber filter device containing immobilized protamine (defined as a protamine filter) was developed. In vivo experiments with dogs showed that the filter not only removed more than 80% of the anticoagulant activity of heparin, but also caused no clinically significant hemodynamic response. In addition, the protamine filter also significantly attenuated both the thrombocytopenic and granulocytopenic responses associated with the use of protamine. Moreover, the use of immobilized protamine considerably reduced activation of the blood complement system by free protamine.