Heparin、Warfarin及决定它们的实验室检查

🧠 为什么重要

Heparin在数分钟内起效；IV输注用aPTT监测，治疗目标约为对照值的1.5至2.5倍（通常约60至80秒，具体取决于实验室）。解毒剂是PROTAMINE SULFATE。注意heparin诱导的血小板减少症：血小板较基线下降50%或更多，或计数低于100,000，通常在heparin开始后5至10天出现；停用所有heparin并报告。低分子量heparin（enoxaparin）经皮下注射于腹部，注射器中的气泡保留，不要揉搓注射部位。Warfarin需3至5天才起效（因此与heparin重叠使用），用INR监测，通常目标为2至3（某些机械瓣膜为2.5至3.5），用VITAMIN K（phytonadione）逆转；妊娠期禁用。教导患者保持vitamin K摄入一致，未经批准不要使用aspirin或NSAIDs，使用电动剃须刀和软毛牙刷，并报告黑便、尿血、牙龈出血或异常瘀伤。直接口服抗凝药（apixaban、rivaroxaban、dabigatran）无需常规实验室监测；dabigatran用idarucizumab逆转。

HEPARIN works within minutes; IV infusions are monitored with aPTT, with a therapeutic goal of about 1.5 to 2.5 times the control value (often about 60 to 80 seconds, depending on the laboratory). The antidote is PROTAMINE SULFATE. Watch for HEPARIN-INDUCED THROMBOCYTOPENIA: a platelet drop of 50% or more from baseline or a count below 100,000, usually 5 to 10 days after heparin starts; stop all heparin and report. Low-molecular-weight heparin (enoxaparin) is given subcutaneously in the abdomen, with the air bubble left in the syringe and without rubbing the site. WARFARIN takes 3 to 5 days to work (so it overlaps with heparin), is monitored with the INR, with a usual goal of 2 to 3 (2.5 to 3.5 for some mechanical valves), and is reversed with VITAMIN K (phytonadione); it is contraindicated in pregnancy. Teach consistent vitamin K intake, no aspirin or NSAIDs without approval, an electric razor and a soft toothbrush, and to report black stools, blood in urine, bleeding gums or unusual bruising. Direct oral anticoagulants (apixaban, rivaroxaban, dabigatran) need no routine lab monitoring; dabigatran is reversed with idarucizumab.

🏥 真实场景

📉 一名接受heparin滴注第6天的患者aPTT为110秒，尿中出现新发血迹。护士停止输注，通知医疗提供者并准备protamine。次日，heparin治疗第7天，血小板从220,000降至90,000：怀疑heparin诱导的血小板减少症。所有heparin，包括冲管液，都永久停用，并通知医疗提供者。两个不同的问题，一种药物，都被考试要求你掌握的实验室检查发现了。

📉 A client on day 6 of a heparin drip has an aPTT of 110 seconds and new blood in the urine. The nurse stops the infusion, notifies the provider and prepares protamine. The next day, day 7 of heparin therapy, the platelets have dropped from 220,000 to 90,000: suspected heparin-induced thrombocytopenia. All heparin, including flushes, is stopped permanently and the provider is notified. Two different problems, one drug, both caught by the labs the exam expects you to know.

📌 要点总结

• heparin用aPTT，warfarin用INRaPTT for heparin, INR for warfarin
• Protamine逆转heparin；vitamin K逆转warfarinProtamine reverses heparin; vitamin K reverses warfarin
• heparin开始后5至10天血小板下降50%或更多（或低于100,000）提示HIT：停用所有heparin并报告A platelet drop of 50% or more (or below 100,000) 5 to 10 days into heparin suggests HIT: stop all heparin and report

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