護理師準備對一位有深部靜脈栓塞病史的病人給予華法林（Warfarin）。給藥前應評估哪一項檢驗數值？
A nurse is preparing to administer warfarin to a client with a history of deep vein thrombosis. Which laboratory value should the nurse evaluate before administration?
- AHemoglobin level血紅素濃度
- BaPTT活化部分凝血活酶時間 (aPTT)
- CPT/INR✓ 正解凝血酶原時間/國際標準比值 (PT/INR)
- DPlatelet count血小板計數
華法林主要影響凝血因子合成，其抗凝血效能是透過 PT/INR（凝血酶原時間/國際標準化比率）來監測。aPTT 是用於肝素（Heparin）的監測指標。給藥前需確保數值在治療範圍內，若數值過高則需通知醫師暫停給藥，以免病人發生出血風險。
Warfarin inhibits the synthesis of vitamin K-dependent clotting factors, so its therapeutic effect must be monitored using the Prothrombin Time (PT) and International Normalized Ratio (INR). The activated Partial Thromboplastin Time (aPTT) is used to monitor heparin therapy, not warfarin. Before administration, the nurse must ensure the INR is within the therapeutic range; if it is too high, the provider should be notified to prevent bleeding risks.
美國常利用 Point-of-care 測試儀器進行 INR 即時監測；台灣臨床多依賴檢驗科出報告，時效性有時較慢。