病人被診斷出低血鉀，護理師應密切監測下列哪項臨床表現？

低血鉀會影響神經肌肉傳導，導致肌肉無力、疲勞，嚴重者甚至出現呼吸肌癱瘓。A（反射亢進）通常見於低血鈣；C（QT 間期縮短）見於高血鈣，低血鉀通常引起 U 波或 ST 段下降；D（腹瀉）是造成低血鉀的原因而非後果，低血鉀常導致腸蠕動減慢，引發便秘或腸麻痺。

Hypokalemia disrupts cell membrane potentials, leading to neuromuscular irritability and resulting in symptoms such as muscle weakness and fatigue. While diarrhea can cause hypokalemia, the condition itself typically leads to constipation or paralytic ileus due to decreased gastrointestinal motility. Additionally, hypokalemia is associated with ST-segment depression and U waves on an ECG, rather than a shortened QT interval.

美國護理師常需評估鉀離子補充後的持續監測；台灣臨床則極度依賴實驗室數據回報。