護理師準備對一位心房顫動的病人給予華法林（Warfarin）。病人目前的 INR 為 4.5。哪項處置最為適當？
A nurse is preparing to administer warfarin to a client with atrial fibrillation. The client's current INR is 4.5. Which action is most appropriate?
- AAdminister the dose as ordered依指示給藥
- BAdminister Vitamin K subcutaneously皮下注射維生素 K
- CIncrease the dose to reverse the effect增加劑量以逆轉效果
- DHold the dose and notify the physician✓ 正解暫停給藥並通知醫師
華法林（Warfarin）的治療監測指標為國際標準化比值（INR）。治療心房顫動的目標 INR 通常介於 2.0 至 3.0 之間。當 INR 達到 4.5 時，表示病人的凝血時間過長，出血風險顯著升高。護理師的職責是「暫停給藥（hold the dose）」並立即通知醫師，由醫師評估是否需要減量、暫停或使用拮抗劑，護理師切勿擅自給藥或更改劑量。
The therapeutic monitoring indicator for warfarin is the International Normalized Ratio (INR). For atrial fibrillation, the target INR is typically between 2.0 and 3.0. An INR of 4.5 indicates that the client's clotting time is excessively prolonged and the bleeding risk is significantly elevated. The nurse's responsibility is to hold the dose and immediately notify the physician, who will determine whether dose reduction, suspension, or administration of an antidote is required. The nurse must not administer the medication or modify the dose independently.