護理師正在指導一位剛開始服用華法林（Warfarin）的病人。下列哪項飲食指導最為重要？
A nurse is educating a client who has a new prescription for Warfarin. Which dietary instruction is most important to include?
- AAvoid all green leafy vegetables entirely完全避免食用所有綠葉蔬菜
- BLimit fluid intake to less than 1 liter per day將液體攝取量限制在每天少於 1 公升
- CMaintain a consistent intake of foods high in Vitamin K✓ 正解維持高維生素 K 食物的攝取量一致
- DIncrease intake of foods high in Vitamin K to prevent bleeding增加高維生素 K 食物的攝取以預防出血
Warfarin（華法林）是一種維生素 K 拮抗劑，透過抑制依賴維生素 K 的凝血因子合成來達到抗凝血效果。病人教育的核心不在於「禁止」攝取維生素 K，而在於「維持攝取量的穩定」。如果攝取量突然增加（如吃了一大盤菠菜），會抵消藥效，降低 INR，增加血栓風險；反之若突然減少，則藥效會增強，增加出血風險。因此，「一致性（Consistency）」是護理指導的關鍵。選項 A（完全避免）在現實中難以達成且不必要；選項 D（增加攝取）會讓抗凝血效果喪失；選項 B（限水）與華法林的藥理機制無直接關聯。護理師應指導病人識別富含維生素 K 的食物（如羽衣甘藍、菠菜、花椰菜），並建議每天攝取量保持恆定。
Warfarin is a vitamin K antagonist that produces its anticoagulant effect by inhibiting the synthesis of vitamin K-dependent clotting factors. The focus of patient teaching is not prohibition of vitamin K intake but maintaining a consistent intake. A sudden increase in intake (such as eating a large plate of spinach) counteracts the drug's effect, lowers the INR, and increases the risk of thrombosis; conversely, a sudden decrease enhances the drug's effect and increases the risk of bleeding. Consistency is therefore the key teaching point. Option A (avoiding intake entirely) is unrealistic and unnecessary; option D (increasing intake) eliminates the anticoagulant effect; option B (fluid restriction) is not directly related to warfarin's mechanism. The nurse should teach the patient to recognize foods rich in vitamin K (such as kale, spinach, and broccoli) and to keep daily intake constant.
在美國，Warfarin 的劑量調整常由藥劑師主導的「抗凝血門診（Anticoagulation Clinic）」負責，護理師需與藥師密切配合教育；台灣則多由主治醫師根據診間抽血結果調整。美國衛教非常強調「Consistency」這個字，而台灣有時會簡化成「少吃綠葉蔬菜」，這在 NCLEX 中會被視為不夠精確。