NCLEX-RNPharmacological and Parenteral TherapiesHard
A client receiving IV magnesium sulfate for preeclampsia has the following assessment findings: respiratory rate 10 breaths/min, absent deep tendon reflexes, and urine output of 20 mL over the past hour. Which action should the nurse take first?
- AStop the magnesium sulfate infusion and prepare to administer calcium gluconate
- BIncrease the magnesium sulfate infusion rate to prevent seizures
- CAdminister a dose of naloxone to reverse respiratory depression
- DContinue the current infusion rate and reassess in 1 hour
Show answer & explanationAnswer & explanation
Correct answer: A. Stop the magnesium sulfate infusion and prepare to administer calcium gluconate
Respiratory rate below 12/min, absent deep tendon reflexes, and oliguria are classic signs of magnesium toxicity. The nurse should stop the infusion immediately and prepare to administer calcium gluconate, the antidote for magnesium sulfate toxicity, while supporting airway and breathing.
Why the other options are wrong
- B. Increasing the infusion would worsen life-threatening magnesium toxicity.
- C. Naloxone reverses opioids, not magnesium sulfate toxicity.
- D. Continuing the infusion risks progression to respiratory arrest and cardiac complications.
Magnesium Sulfate Toxicity
Excess serum magnesium causes loss of deep tendon reflexes, respiratory depression, and decreased urine output; calcium gluconate is the antidote.
- Therapeutic magnesium level for preeclampsia: 4-7 mEq/L
- Toxicity signs: absent DTRs, RR <12/min, oliguria, decreased LOC
- Antidote: calcium gluconate IV
Memory trick: 'No reflex, no breath, no pee — stop the Mag and call for Ca'