護理師準備對一位心房顫動病人投予 warfarin，現階段國際標準化比值（INR）為 4.5。哪項處置最合適？
A nurse is preparing to administer warfarin to a client with a history of atrial fibrillation. The client's current INR is 4.5. Which action is most appropriate?
- AAdminister the dose as scheduled按預定時間給藥
- BAdminister half the dose給予半劑量
- CHold the dose and notify the provider✓ 正解暫停給藥並通知醫療提供者
- DAdminister a dose of Vitamin K給予維生素 K 劑量
Warfarin 治療窗範圍通常在 INR 2.0-3.0 之間（視病況而定）。INR 4.5 已顯著高於治療水平，代表出血風險極高。護理師應先暫停給藥，避免凝血功能進一步惡化，並通知醫師評估是否需要調整劑量或監測出血跡象，不應自行擅作主張減量或施打維生素 K。
The therapeutic INR range for warfarin is typically 2.0–3.0 (depending on indication). An INR of 4.5 is significantly above the therapeutic level and indicates a very high bleeding risk. The nurse should hold the dose to avoid further worsening of coagulation, then notify the physician to assess whether dose adjustment is needed or to monitor for signs of bleeding. The nurse should not independently reduce the dose or administer vitamin K.
台美兩地護理師對 warfarin 監測高度重視，但美國有更多藥師參與劑量調整指引，台灣則多由內科醫師根據數值直接開立醫囑。