A 28-year-old woman at 36 weeks gestation with pre-eclampsia with severe features is started on magnesium sulfate. Two hours later she becomes areflexic with a respiratory rate of 10/min. Serum magnesium level is 9 mg/dL. What is the IMMEDIATE treatment?

• A Stop magnesium sulfate infusion only
• B Intravenous diazepam 10 mg
• C Sodium bicarbonate 50 mEq IV
• D Intravenous calcium gluconate 1 g over 3 minutes ✓

Explanation

Magnesium toxicity with respiratory depression and areflexia is treated immediately with IV calcium gluconate 1 g (10 mL of 10% solution) given over 3 minutes, which antagonises magnesium at the neuromuscular junction. Stopping the infusion alone is insufficient when respiratory compromise is present; diazepam and bicarbonate are not antidotes for magnesium toxicity.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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