護理師照顧一位接受螺內酯（Spironolactone）的病人。護理師應最密切監測哪項檢驗值？
A nurse is caring for a client receiving Spironolactone. Which laboratory value should the nurse monitor most closely?
- ASerum Glucose血清葡萄糖
- BSerum Sodium血清鈉
- CSerum Potassium✓ 正解血清鉀
- DSerum Calcium血清鈣
螺內酯（Spironolactone）是一種醛固酮拮抗劑（aldosterone antagonist），屬於保鉀利尿劑（potassium-sparing diuretic）。它的作用機制是在腎臟的遠端腎小管和集尿管（collecting ducts）處，競爭性地阻斷醛固酮受體。醛固酮通常會促進鈉和水的再吸收，同時增加鉀的排泄。當螺內酯阻斷醛固酮的作用時，會導致鈉和水從體內排出，但同時保留鉀離子。 因此，服用螺內酯的病人最主要的風險是體內鉀離子累積過多，導致高鉀血症（hyperkalemia）。高鉀血症是一種嚴重的電解質失衡，可能引起心律不整，甚至危及生命。護理師必須密切監測病人的血清鉀離子水平，並教導病人避免攝取高鉀食物或鉀補充劑，以預防此併發症。
Spironolactone is an aldosterone antagonist and is classified as a potassium-sparing diuretic. Its mechanism of action involves competitively blocking aldosterone receptors in the distal renal tubule and collecting ducts. Aldosterone normally promotes reabsorption of sodium and water while increasing potassium excretion. When spironolactone blocks aldosterone's action, sodium and water are excreted while potassium is retained. Therefore, the main risk for clients taking spironolactone is excessive accumulation of potassium, leading to hyperkalemia. Hyperkalemia is a serious electrolyte disturbance that can cause cardiac dysrhythmias and may be life-threatening. The nurse must closely monitor the client's serum potassium level and instruct the client to avoid high-potassium foods or potassium supplements to prevent this complication.