Heparin-induced thrombocytopenia.
Heparin-induced thrombocytopenia (HIT) is an antibody-mediated reaction caused by exposure to heparin that can lead to devastating thrombotic complications. HIT usually occurs 5 to 10 days after exposure to heparin but can happen more rapidly to patients who are reexposed to heparin within 100 days. The hallmark of this disorder is a sudden drop in platelet count of greater than 50%. Once HIT is suspected the heparin must be immediately discontinued and an anticoagulant (direct thrombin inhibitor or heparinoid) started. For patients presenting for cardiac surgery and cardiopulmonary bypass that have a history of HIT and positive antibodies a direct thrombin inhibitor such as lepirudin, argatroban or bivalirudin must be used in lieu of heparin.
Szokol
Joseph W
JW
University of Chicago, Pritzker School of Medicine, Chicago, Illinois, USA. jszokol@aol.com
D000925:Anticoagulants / Q000009:adverse effects* / Q000494:pharmacology / Q000627:therapeutic use; D006348:Cardiac Surgical Procedures / Q000379:methods; D002315:Cardiopulmonary Bypass / Q000379:methods; D006493:Heparin / Q000009:adverse effects*; D006801:Humans; D010976:Platelet Count; D013917:Thrombin / Q000037:antagonists & inhibitors; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000276:immunology; D013997:Time Factors
D000925:Anticoagulants; D006493:Heparin; D013917:Thrombin