護理師正監測一位因子癇前症接受靜脈輸注硫酸鎂（magnesium sulfate）的病人。哪項評估發現表示發生了鎂中毒？
A nurse is monitoring a client receiving an intravenous infusion of magnesium sulfate for preeclampsia. Which assessment finding indicates magnesium toxicity?
- ABlood pressure of 140/90 mmHg血壓 140/90 mmHg
- BHyperactive deep tendon reflexes (4+)深腱反射亢進 (4+)
- CRespiratory rate of 10 breaths per minute✓ 正解呼吸頻率為每分鐘 10 次
- DUrine output of 50 mL/hr尿量 50 mL/hr
硫酸鎂用於預防子癇前症引發的抽搐，它具有中樞神經系統抑制作用。當血鎂濃度過高（中毒）時，會由輕而重出現以下徵兆：深腱反射（DTR）消失、呼吸抑制、心律不整甚至心跳停止。呼吸頻率 10 次/分（C）低於正常範圍（12-20），是鎂中毒的明確早期警訊。選項 B 的深腱反射亢進是子癇前症本身的表現，中毒時應該是反射『消失』。尿量 50 mL/hr（D）是正常的（應 >30 mL/hr），若尿量減少反而會增加鎂中毒風險。血壓（A）是疾病現況，非中毒指標。護理師在給藥期間必須隨時準備好解毒劑——葡萄糖酸鈣（Calcium gluconate）。
Magnesium sulfate is used to prevent seizures in preeclampsia and exerts central nervous system depression. When the serum magnesium level becomes too high (toxicity), the following signs appear in order of increasing severity: loss of deep tendon reflexes (DTRs), respiratory depression, arrhythmia, and even cardiac arrest. A respiratory rate of 10 breaths/min (C) is below the normal range (12-20) and is a clear early warning sign of magnesium toxicity. The hyperreflexia in option B is a manifestation of preeclampsia itself; in toxicity, the reflexes should be absent. A urine output of 50 mL/hr (D) is normal (should be >30 mL/hr); a decrease in urine output instead increases the risk of magnesium toxicity. Blood pressure (A) reflects the disease status, not toxicity. During administration, the nurse must always have the antidote, calcium gluconate, ready.
在美國產科護理中，Magnesium Sulfate 的滴定與監測有非常嚴格的評估量表。台灣臨床實務相同，但護理師需注意美國 NCLEX 考試中對『呼吸 < 12』或『DTR 消失』作為停藥指標的絕對性。