— 生理適應 · MEDIUM · MCQ —
護理師評估一位疑似電解質不平衡的病人，下列哪項發現與低血鉀症一致？
A nurse is assessing a client for electrolyte imbalances. Which assessment finding is consistent with hypokalemia?
- APeaked T wavesT波尖峰
- BIncreased bowel sounds腸鳴音增加
- CConstipation✓ 正解便秘
- DHyperreflexia反射亢進
— Explanation · 中文詳解 —
低血鉀症（Hypokalemia）會影響神經肌肉傳導與平滑肌功能。鉀離子是細胞內主要陽離子，參與細胞膜電位維持。當血鉀過低，會導致神經與肌肉興奮性降低，臨床表徵包括肌肉無力、腸蠕動減慢（便秘、腹脹、麻痺性腸阻塞）。選項C（便秘）是平滑肌張力減弱的典型表現。選項B、D、A均與低血鉀的病理生理機轉不符。
Hypokalemia affects neuromuscular transmission and smooth-muscle function. Potassium is the principal intracellular cation, maintaining membrane potential. Low serum K decreases neuromuscular excitability—muscle weakness and reduced GI motility (constipation, distension, paralytic ileus) are typical. Option C (constipation) reflects reduced smooth-muscle tone. Options B, D, and A do not fit hypokalemia's pathophysiology.