Heparin-Induced Thrombocytopenia

Abstract

Serious limband life-threatening thromboembolic complications may result from immune-mediated, heparin-induced thrombocytopenia (HIT) type II. The authors describe three such cases associated with devastating outcomes. The clinical diagnosis of HIT II was based on (1) falling platelet count on heparin (< 150,000/mm3), (2) thromboembolic events on heparin, and (3) absence of new thrombotic events after heparin discontinuation. These distinct case presentations are discussed to broaden clinical awareness of HIT II. A high index of suspicion is warranted to prevent this catastrophic complication.