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)納洛酮 (Narcan)
- BProtamine Sulfate硫酸魚精蛋白
- CPotassium Chloride氯化鉀
- DCalcium Gluconate✓ 正解葡萄糖酸鈣
本題測驗產科與急重症藥理學中最致命的殺手：硫酸鎂中毒（Magnesium Toxicity）。將硫酸鎂靜脈給予早產或重度子癲前症產婦，其目的是為了阻礙肌肉與神經突觸的傳導，以此來放鬆子宮肌或是防堵大腦抽搐。但一旦它的濃度進入毒性領域（例如超過 8-10 mEq/L），它會像毒氣一樣全面癱瘓神經系統。它首當其衝壓制深部肌腱反射，病患的膝跳反射會完全消失（Loss of DTRs）。若不理會，接下來它會切斷呼吸肌的驅動力導致窒息（Respiratory depression < 12 次/分），以及最終的心跳停止（Cardiac arrest）。因為鎂主要由腎臟排出，當尿量過低（< 30 mL/hr）時，毒素極易累積。若看見 DTRs 為零與低速且極度危險的呼吸，護理師必須立刻關閉鎂點滴，並準備這唯一的生理拮抗救命神藥：「葡萄糖酸鈣（Calcium Gluconate）」（選項D正確）。鈣離子在神經突觸通道上是鎂的直接競爭對手，靜脈推注能瞬間驅逐鎂離子，恢復骨骼肌與呼吸中樞的功能。選項A解鴉片過量。選項B解肝素抗凝。選項C點滴推注鉀離子更是直接引發心臟停止跳動的純禁忌謀殺手段。
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.
「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。