The nurse is preparing to administer magnesium sulfate to a laboring client whose blood pressure has increased from 110/60 mm Hg to 140/90 mm Hg. Which nursing protocol has the highest priority?

Rationale: A. Assess deep tendon reflexes (DTRs) every 4 hours: Monitoring DTRs is essential to detect early signs of magnesium toxicity, but the frequency of assessment alone does not immediately prevent life-threatening complications. B. Provide a quiet environment with subdued lighting: A calm environment helps reduce maternal stress and may support labor progression, but it does not address the primary safety concern associated with magnesium sulfate therapy. C. Have calcium gluconate immediately available: Calcium gluconate is the antidote for magnesium sulfate toxicity. Having it readily available is the highest priority because magnesium toxicity can rapidly depress neuromuscular and respiratory function, requiring immediate intervention. D. Insert an indwelling urinary catheter with a urimeter to monitor hourly output: Monitoring urine output is important to assess renal function and magnesium excretion, but immediate availability of the antidote takes precedence in preventing life-threatening complications.