病人被診斷為低血鉀，護理師應優先評估下列哪項臨床表現？
A client is diagnosed with hypokalemia. Which finding should the nurse prioritize for assessment?
- ADecreased bowel sounds腸蠕動音減少
- BPresence of muscle cramps出現肌肉痙攣
- CMuscle weakness肌無力
- DIrregular heart rhythm✓ 正解心律不整
低血鉀（Hypokalemia）會影響細胞膜的靜止電位，導致神經肌肉與心肌興奮性改變。其中最危險的併發症是心律不整（Arrhythmia），因為心肌對鉀離子濃度極度敏感，電位異常可能引發致命性的心室顫動（Ventricular fibrillation）。因此，在 ABC 原則（Airway, Breathing, Circulation）下，循環系統的穩定性（心跳）永遠是優先評估對象。
Hypokalemia affects the resting membrane potential of cells, leading to altered neuromuscular and myocardial excitability. The most dangerous complication is cardiac arrhythmia, as the myocardium is extremely sensitive to potassium concentration, and electrical disturbances may precipitate lethal ventricular fibrillation. Therefore, under the ABC (Airway, Breathing, Circulation) principle, stability of the circulatory system (heart rhythm) is always the priority assessment.