Anticoagulation in extracorporeal circulation using recombinant hirudin: a case report.

Heparin-induced thrombocytopenia (HIT) is a severe complication following the application of heparin; antibodies against complexes of heparin and PDF4 initiate activation of platelets. This may lead to massive thrombembolism, which is associated with a slight and transient drop of platelets in HIT I or a drop below 50% after approximately 5 days in HIT II. Further administration of heparin has to be strictly avoided in these patients. Immunologic evidence for HIT can easily be obtained by the heparin-induced platelet aggregation assay. If anticoagulation is necessary, different, alternative drugs are available. Recombinant hirudin (r-hirudin) is a well-established drug for safe anticoagulation. Monitoring is possible by estimating the plasma level of r-hirudin from the ecarin-clotting time. We report a case of a patient with prosthetic aortic valve endocarditis and HIT II who suffered from massive postoperative bleeding requiring massive substitution of blood components and coagulants caused by free circulating r-hirudin due to the use of a hemofilter.