病人診斷為低血鉀，護理師在評估時應優先關注哪一項發現？
A client is diagnosed with hypokalemia. Which finding should the nurse prioritize during the assessment?
- AGeneral fatigue and lethargy全身疲倦和嗜睡
- BMuscle cramps in the lower extremities下肢肌肉痙攣
- CIrregular heart rate and rhythm✓ 正解心律不整和節律異常
- DDecreased bowel sounds腸鳴音減弱
鉀離子參與心肌細胞的去極化與再極化過程。低血鉀（Hypokalemia）會導致心肌興奮性異常，極易誘發頻脈、期外收縮（PVCs）甚至致命性心律不整（如 Torsades de pointes）。雖然肌肉無力（B）、腸蠕動減慢（D）與疲倦（A）皆為低血鉀表現，但「心律不整」直接危及循環穩定，是護理評估中最優先的關注項目。
Potassium participates in the depolarization and repolarization of cardiac cells. Hypokalemia causes abnormal cardiac excitability and easily provokes tachycardia, premature ventricular contractions (PVCs), and even fatal dysrhythmias such as torsades de pointes. Although muscle weakness (B), decreased intestinal motility (D), and fatigue (A) are also features of hypokalemia, dysrhythmias directly threaten circulatory stability and are therefore the priority focus of nursing assessment.