一位懷孕30週的32歲經產婦因正經歷著強烈早產宮縮而被收治入院。產科醫師積極啟動了高劑量連續靜脈輸注的硫酸鎂（Magnesium Sulfate）作為安胎藥，以猛烈阻斷平滑肌宮縮。在藥物治療六小時後，護理師進行每小時例行檢查。她發現個案的髕骨深部肌腱反射 (DTRs) 驚人地竟然完全消失為零 (+0)，其呼吸速率也極度危險地墜落到僅 9 次/分，且每小時尿量降至低於 20 mL。當護理師認出了這場災難性的鎂離子中毒後，必須緊急準備何種明確的藥理學解毒劑來對抗此藥物？
A 32-year-old multigravida client at 30 weeks' gestation is admitted experiencing potent preterm labor contractions. The obstetric provider aggressively initiates a high-dose continuous intravenous infusion of Magnesium Sulfate functioning as a tocolytic to aggressively halt the contractions. Six hours into the medication therapy, the nurse performs an hourly check. The nurse discovers the client's patellar deep tendon reflexes (DTRs) are shockingly entirely absent (+0), her respiratory rate has perilously plummeted to 9 breaths per minute, and her hourly urine output has dropped below 20 mL. Recognizing catastrophic Magnesium poisoning, what explicit pharmacological antidote must the nurse urgently prepare to counteract this drug?
- ANaloxone (Narcan)
- BProtamine Sulfate硫酸魚精蛋白
- CPotassium Chloride氯化鉀
- DCalcium Gluconate葡萄糖酸鈣正確答案
- D葡萄糖酸鈣
本題測驗產科與重症藥理學中的硫酸鎂中毒（Magnesium Toxicity）。將硫酸鎂靜脈給予早產或子癲前症產婦，目的是抑制肌肉與神經突觸傳導以放鬆子宮肌或預防抽搐；一旦血清鎂濃度進入毒性範圍，會依序抑制神經肌肉功能：治療濃度約4-8 mg/dL，深部肌腱反射（DTR）消失約發生於8-12 mg/dL，呼吸抑制約發生於12-16 mg/dL；明顯中毒徵象在部分病人可能於4-5 mg/dL以上即出現，個體差異大。鎂主要經腎臟排出，尿量過低（<30 mL/hr）時毒素容易累積。護理師若發現DTR消失合併呼吸速率過低，須立即停止硫酸鎂輸注，並準備解毒劑葡萄糖酸鈣（Calcium Gluconate，選項D）：鈣離子在神經突觸通道上與鎂互相拮抗，靜脈給予可協助恢復骨骼肌與呼吸中樞功能。選項A為鴉片類過量的解毒劑；選項B為肝素的解毒劑；選項C（靜脈推注鉀離子）屬於絕對禁忌，可直接導致心跳停止。
- ANaloxone (Narcan)
Naloxone 專門用以取代中樞受器上的麻醉鴉片類藥物（嗎啡、海洛因）。鎂離子所施加的肌肉阻斷與鴉片途徑完全無關。
- B硫酸魚精蛋白
Protamine Sulfate 只不過是在體內與循環的肝素鏈結合；它對由鎂中毒推動、即將發生的呼吸災難完全無能為力。
- C氯化鉀
給予測量為大劑量的純氯化鉀點滴推注，諷刺地這正好是應用於致命死刑的確切方法；這將毫無疑問地讓病患的心臟立刻停止。
- D · 正確答案葡萄糖酸鈣
在生化學上，鈣離子擔任著神經肌肉交界處對抗鎂離子的兇猛直接拮抗劑；快速注射葡萄糖酸鈣能拯救被壓碎的呼吸驅力，並瞬間復甦癱瘓的肌肉。
「Magnesium Toxicity 缺反射缺呼吸 = 解毒劑 Calcium Gluconate (葡萄糖酸鈣)」。這是產房護理師最重要的最後一道防線，台灣與美國產科國考保證絕對會出現這對藥物與其臨床判斷特徵。
English explanation
This question tests the most lethal killer in obstetric and critical care pharmacology: magnesium sulfate toxicity. Magnesium sulfate is administered intravenously to women with preterm labor or severe preeclampsia to block muscle and neuromuscular junction transmission, thereby relaxing uterine muscle or preventing seizures. However, once concentrations enter the toxic range (e.g., above 8-10 mEq/L), it acts like a paralyzing gas across the nervous system. It first suppresses deep tendon reflexes; the patient's knee-jerk reflex completely disappears (Loss of DTRs). If ignored, it next removes the drive to the respiratory muscles, causing suffocation (respiratory depression < 12 breaths/min) and ultimately cardiac arrest. Because magnesium is primarily excreted by the kidneys, when urine output is low (< 30 mL/hr), toxin accumulation easily occurs. If DTRs are absent and respirations are slow and extremely dangerous, the nurse must immediately stop the magnesium infusion and prepare the only physiological antidote: calcium gluconate (option D is correct). Calcium ions are direct competitors of magnesium at the neuromuscular junction; an IV push can immediately displace magnesium and restore skeletal muscle and respiratory center function. Option A reverses opioid overdose. Option B reverses heparin anticoagulation. Option C, IV push of potassium, is a strict contraindication that directly causes cardiac arrest.
最近修訂：2026-10-05