一位患有心臟衰竭的病人正在接受口服呋塞米（Furosemide）治療。哪項實驗室結果最讓護理師感到擔心？
A client with heart failure is receiving oral furosemide. Which laboratory result would be most concerning to the nurse?
- ABUN 18 mg/dLBUN 18 mg/dL
- BCreatinine 1.0 mg/dL肌酸酐 1.0 mg/dL
- CSodium 136 mEq/L鈉 136 mEq/L
- DPotassium 3.2 mEq/L✓ 正解鉀 3.2 mEq/L
Furosemide 是一種排鉀利尿劑（Loop diuretic），最常見且危險的副作用是低血鉀。正常血鉀範圍為 3.5-5.0 mEq/L，3.2 mEq/L（D）屬於低血鉀，會增加心律不整及地高辛中毒的風險，對於心臟衰竭病人尤為危險。選項 C、A、B 均在正常範圍內（鈉 135-145、BUN 7-20、Cr 0.6-1.2）。護理師在監測利尿劑療效時，必須具備識別電解質紊亂的能力，這是預防心血管風險的重要環節。這題屬於基礎但關鍵的檢驗值判讀。
Furosemide is a potassium-wasting loop diuretic, and its most common and dangerous adverse effect is hypokalemia. The normal serum potassium range is 3.5-5.0 mEq/L; a value of 3.2 mEq/L (Option D) indicates hypokalemia, increasing the risk of cardiac arrhythmias and digoxin toxicity -- particularly dangerous in clients with heart failure. Options C, A, and B are all within normal limits (sodium 135-145, BUN 7-20, creatinine 0.6-1.2). When monitoring the effect of diuretics, the nurse must be able to recognize electrolyte disturbances, as this is a key component in preventing cardiovascular complications. This item assesses a basic but critical laboratory interpretation skill.
美國 NCLEX 常考排鉀與保鉀利尿劑的電解質差異；台灣臨床中，護理師在給予利尿劑前，除了看血鉀，還會特別注意病人的血壓（BP）是否過低。