Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada.
Division of Hematology and Transfusion Medicine, University Health Network, Toronto, ON, Canada.
Chest. 2018 Sep;154(3):678-690. doi: 10.1016/j.chest.2017.11.039. Epub 2017 Dec 16.
Heparin-induced thrombocytopenia (HIT) is associated with clinically significant morbidity and mortality. Patients who are critically ill are commonly thrombocytopenic and exposed to heparin. Although HIT should be considered, it is not usually the cause of thrombocytopenia in the medical-surgical ICU population. A systematic approach to the patient who is critically ill who has thrombocytopenia according to clinical features, complemented by appropriate laboratory confirmation, should lead to a reduction in inappropriate laboratory testing and reduce the use of more expensive and less reliable anticoagulants. If the patient is deemed as being at intermediate or high risk for HIT or if HIT is confirmed by means of the serotonin-release assay, heparin should be stopped, heparin-bonded catheters should be removed, and a direct antithrombin or fondaparinux should be initiated to reduce the risk of thrombosis. Warfarin is absolutely contraindicated in the acute phase of HIT; if administered, its effects must be reversed by using vitamin K.
肝素诱导的血小板减少症（HIT）与临床显著的发病率和死亡率相关。危重症患者通常会出现血小板减少症，并接触肝素。尽管应考虑 HIT，但它通常不是医疗外科 ICU 人群血小板减少症的原因。根据临床特征对患有血小板减少症的危重症患者进行系统评估，并辅以适当的实验室确认，应减少不必要的实验室检查，并减少使用更昂贵且不太可靠的抗凝剂。如果患者被认为处于 HIT 的中危或高危状态，或者如果通过 5-羟色胺释放试验确认 HIT，则应停用肝素，移除肝素结合导管，并启动直接抗凝血酶或磺达肝素钠，以降低血栓形成的风险。华法林在 HIT 的急性期绝对禁忌；如果给予，必须使用维生素 K 逆转其作用。
