一位心臟衰竭病人正在服用呋塞米 (furosemide)，護理師應最密切監測哪項檢驗數值以預防併發症？
A client with heart failure is receiving furosemide. Which laboratory value should the nurse monitor most closely to prevent complications?
- ABlood urea nitrogen (BUN)血尿素氮 (BUN)
- BSerum potassium✓ 正解血清钾
- CSerum sodium血清钠
- DSerum calcium血清钙
核心概念：藥物副作用監測。Furosemide 是排鉀利尿劑（loop diuretic），最常見且危險的副作用是低鉀血症（hypokalemia）。為何正確答案對：低鉀會引發嚴重的心律不整，甚至增加毛地黃中毒的風險。為何其他選項錯：鈉（C）雖也會受影響但影響心臟電氣生理不如鉀直接；鈣（D）受影響較小；BUN（A）雖能反映腎灌流與脫水狀況，但鉀離子的電解質失衡在急迫性上更高。臨床思路：對於使用特定藥物的病人，護理師必須預見（anticipate）潛在的實驗室數值變化，並在數值達到危險值前採取預防措施。
Core concept: monitoring for medication side effects. Furosemide is a potassium-wasting loop diuretic, and its most common and dangerous adverse effect is hypokalemia. Why the correct answer is correct: hypokalemia can precipitate serious dysrhythmias and increase the risk of digoxin toxicity. Why other options are incorrect: sodium (C) is also affected, but its effect on cardiac electrical activity is less direct than potassium; calcium (D) is less affected; BUN (A) can reflect renal perfusion and dehydration but is less urgent than the electrolyte imbalance involving potassium. Clinical reasoning: when a client is on a specific medication, the nurse must anticipate potential laboratory abnormalities and intervene before values reach a dangerous level.
美國護理師常依據預立醫囑 (Standing Orders) 在發現低鉀時直接給予補充藥物；台灣護理師通常需先知會醫師，由醫師開立處方後執行，但兩者皆強調監測的高頻率性。