護理師正在評估一位因子癲前症接受硫酸鎂持續輸注的病人。下列哪項評估發現最令人擔憂，需要立即介入？
A nurse is assessing a client who has been receiving a continuous infusion of magnesium sulfate for preeclampsia. Which assessment finding is most concerning and requires immediate intervention?
- AClient's respiratory rate is 16 breaths/min病人的呼吸頻率為每分鐘 16 次
- BClient reports feeling flushed病人報告感覺臉頰發熱
- CClient's deep tendon reflexes are 0 (absent)✓ 正解病人的深層肌腱反射為 0（消失）
- DClient's urine output is 50 mL in the last hour病人最後一小時的尿液輸出量為 50 mL
硫酸鎂（Magnesium sulfate）廣泛用於子癲前症以預防癲癇發作，但其治療指數窄。腱反射（Deep tendon reflexes）消失是硫酸鎂中毒的早期跡象。若反射消失，顯示藥物濃度已過高，可能進展為呼吸抑制與心跳停止。此時必須立即停藥並通知醫師，準備好鈣離子（如葡萄糖酸鈣）作為解毒劑。
Magnesium sulfate is widely used in preeclampsia to prevent seizures, but it has a narrow therapeutic index. Loss of deep tendon reflexes is an early sign of magnesium toxicity. If reflexes are absent, drug levels are excessive and may progress to respiratory depression and cardiac arrest. At this point, the infusion must be stopped immediately, the physician notified, and calcium (such as calcium gluconate) prepared as the antidote.