Abstract:
Heparin-induced thrombocytopenia (HIT) is a major issue in cardiac surgery requiring cardiopulmonary bypass (CPB). HIT represents a severe adverse drug reaction after heparin administration. It consists of immune-mediated thrombocytopenia paradoxically leading to thrombotic events. Detection of antibodies against platelets factor 4/heparin (anti-PF4/H) and aggregation of platelets in the presence of heparin in functional in vitro tests confirm the diagnosis. Patients suffering from HIT and requiring cardiac surgery are at high risk of lethal complications and present specific challenges. Four distinct phases are described in the usual HIT timeline, and the anticoagulation strategy chosen for CPB depends on the phase in which the patient is categorized. In this sense, we developed an institutional protocol covering each phase. It consisted of the use of a non-heparin anticoagulant such as bivalirudin, or the association of unfractionated heparin (UFH) with a potent antiplatelet drug such as tirofiban or cangrelor. Temporary reduction of anti-PF4 with intravenous immunoglobulins (IvIg) has recently been described as a complementary strategy. In this article, we briefly described the pathophysiology of HIT and focused on the various strategies that can be applied to safely manage CPB in these patients.
摘要:
肝素诱导的血小板减少症(HIT)是需要体外循环(CPB)的心脏手术中的主要问题。HIT代表肝素给药后的严重药物不良反应。它由免疫介导的血小板减少症矛盾地导致血栓事件组成。在功能性体外测试中,在肝素存在下检测抗血小板因子4/肝素(抗-PF4/H)的抗体和血小板聚集证实了诊断。患有HIT并需要心脏手术的患者面临致命并发症的高风险,并面临特殊挑战。在通常的HIT时间表中描述了四个不同的阶段,为CPB选择的抗凝策略取决于患者的分类阶段。在这个意义上,我们制定了涵盖每个阶段的机构协议。它包括使用非肝素抗凝剂,如比伐卢定,或普通肝素(UFH)与强效抗血小板药物如替罗非班或坎格雷洛的联合。用静脉内免疫球蛋白(IvIg)暂时减少抗PF4最近被描述为一种补充策略。在这篇文章中,我们简要描述了HIT的病理生理学,并重点介绍了可用于安全管理这些患者CPB的各种策略.