護理師為心衰竭病人投予口服毛地黃 0.25 mg，下列哪項臨床表現應優先評估以預防中毒？
A nurse is administering digoxin 0.25 mg orally to a client with heart failure. Which clinical finding should the nurse prioritize to prevent toxicity?
- ABlood pressure of 110/70 mmHg血壓 110/70 mmHg
- BApical pulse of 52 beats/min✓ 正解心尖脈搏 52 次/分
- CRespiratory rate of 16 breaths/min呼吸頻率 16 次/分
- DSerum potassium level of 4.2 mEq/L血清鉀濃度 4.2 mEq/L
毛地黃具有負性變時作用，若心跳過慢（成人 <60 bpm）應暫停給藥。心跳過慢不僅是中毒的常見早期指標，給藥後更會惡化心律不整。鉀離子數值雖然重要，但給藥前直接監測心跳是護理師最直接且關鍵的預防步驟，以避免發生致命的心傳導阻滯。
Digoxin has a negative chronotropic effect; if the heart rate is too slow (in adults, <60 bpm), the medication should be withheld. Bradycardia is not only a common early sign of toxicity, but the medication can worsen arrhythmias once administered. Although potassium values are important, directly monitoring the heart rate before administration is the most direct and critical preventive step the nurse can take to avoid fatal cardiac conduction block.
台美臨床評估心尖脈皆為標準規範，但台灣現行病房常以電子血壓計脈搏取代聽診，護理師應具備聽診確認心跳的技能。