— 生理適應 · HARD · MCQ —
護理師照護 SIADH 病人。預期會出現哪項檢驗結果？
A nurse is caring for a client with syndrome of inappropriate antidiuretic hormone (SIADH). Which laboratory result is expected?
- ASerum sodium 150 mEq/L血清鈉 150 mEq/L
- BUrine specific gravity 1.002尿液比重 1.002
- CSerum osmolality 260 mOsm/kg✓ 正解血清滲透壓 260 mOsm/kg
- DHypovolemia低血容量
— Explanation · 中文詳解 —
SIADH（抗利尿激素分泌異常症候群）的核心病理為 ADH 分泌過多，導致腎小管過度再吸收水分，造成體內水分滯留。這會稀釋血漿，導致血清滲透壓下降（稀釋性低血鈉）。選項 C 正確，因為 SIADH 病人的血清滲透壓通常會低於正常的 275-295 mOsm/kg。其他選項皆不符合此病理：血鈉會降低而非升高，尿液會因水分再吸收而濃縮（比重升高），且病人通常為等容積（Euvolemic）而非脫水。
SIADH causes excessive water retention, leading to dilutional hyponatremia and decreased serum osmolality, typically below 275 mOsm/kg. Consequently, urine becomes concentrated with high specific gravity, and the client remains euvolemic rather than hypovolemic.