Agnelli G, Sonaglia F
Istituto di Medicina Interna e Medicina Vascolare, Università di Perugia, Italy.
Int J Cardiol. 1998 May 29;65 Suppl 1:S95-8. doi: 10.1016/s0167-5273(98)00055-2.
The anticoagulant agents most commonly used in the prevention and treatment of pulmonary embolism (PE) are unfractionated heparin, oral anticoagulants, and low molecular weight heparins (LMWHs). Unfractionated heparin at low fixed dose is the prophylactic regimen of choice for PE in patients undergoing general surgery or with serious medical diseases (low to moderate risk patients). In high risk patients perioperative prophylaxis with LMWHs or oral anticoagulants should be adopted. Therapy of pulmonary embolism should start with an intravenous bolus dose of 5000 U heparin followed by an infusion of 1250 U/h. Then the dose should be adjusted to maintain the aPTTX2-2.5 pre-treatment value. Heparin is continued for 7-10 days and is followed by oral anticoagulants for at least 3 months. Unfractionated heparin has some pharmacological limitations, mainly due to the aspecific binding to plasma proteins that limits its anticoagulant effect and causes the heparin resistance observed in some patients with PE and the inter-subject variability of the anticoagulant effect. Other antithrombotic agents such as LMWHs and selective thrombin inhibitors (hirudin and its analogues) do not aspecifically bind to plasma proteins. They have recently been used with promising results in the prevention and treatment of PE. Their definitive value in this clinical setting will be defined by the ongoing clinical trials.
预防和治疗肺栓塞（PE）最常用的抗凝剂是普通肝素、口服抗凝剂和低分子量肝素（LMWH）。低固定剂量的普通肝素是接受普通外科手术或患有严重内科疾病患者（低至中度风险患者）预防PE的首选方案。对于高风险患者，应采用LMWH或口服抗凝剂进行围手术期预防。肺栓塞的治疗应先静脉推注5000 U肝素，然后以1250 U/h的速度输注。然后应调整剂量以维持活化部分凝血活酶时间（aPTT）为治疗前值的2 - 2.5倍。肝素持续使用7 - 10天，随后口服抗凝剂至少3个月。普通肝素存在一些药理学局限性，主要是由于其与血浆蛋白的非特异性结合限制了其抗凝作用，并导致在一些PE患者中观察到肝素抵抗以及抗凝效果的个体间差异。其他抗血栓药物，如LMWH和选择性凝血酶抑制剂（水蛭素及其类似物）不会与血浆蛋白非特异性结合。它们最近在预防和治疗PE方面使用取得了有前景的结果。它们在这种临床情况下的确切价值将由正在进行的临床试验确定。
