A nurse is caring for a client at 28 weeks gestation who is experiencing preterm labor. The client has been receiving magnesium sulfate for 24 hours and now reports feeling weak, having difficulty breathing, and experiencing decreased deep tendon reflexes. What is the priority nursing intervention?

Discontinuing magnesium sulfate infusion and preparing calcium gluconate is the priority for a client showing signs of toxicity (weakness, respiratory difficulty, decreased reflexes). Other options delay critical intervention for this life-threatening condition.

Core Nursing Explanation Key Concept Analysis: This question tests the nurse's ability to recognize and respond to Magnesium sulfate toxicity, a critical and potentially life-threatening complication of a common tocolytic (labor-stopping) and neuroprotective medication. The patient is at 28 weeks gestation, receiving MgSO4 for preterm labor. The symptoms reported—weakness, difficulty breathing, and decreased deep tendon reflexes (DTRs)—are classic signs of magnesium toxicity. The priority is to stop the source of toxicity and administer the antidote.

Answer Rationale: Key Point! The correct answer is to Discontinue the magnesium sulfate infusion and prepare to administer calcium gluconate. This is a direct, life-saving intervention. Calcium gluconate is the specific antidote for magnesium toxicity; it competitively antagonizes magnesium's effects at the neuromuscular junction, helping to reverse respiratory depression and muscle weakness. Discontinuing the infusion stops the ongoing administration of the toxic agent. This action addresses the ABC priority (Airway, Breathing, Circulation) by directly targeting the cause of the client's respiratory difficulty.

Distractor Analysis:
Watch out for confusion! Option ②, "Increase the rate of IV fluids to enhance magnesium excretion," is incorrect because while hydration can support renal excretion, it is a slow, supportive measure, not an emergency intervention for acute toxicity. It does not address the immediate threat to the airway and breathing.
Option ③, "Encourage deep breathing exercises and position the client in high Fowler's," is a supportive measure for respiratory distress but is completely inadequate for a pharmacologically induced neuromuscular blockade. It treats the symptom, not the cause, and delays definitive treatment.
Option ④, "Reduce the magnesium sulfate infusion rate by half and continue monitoring," is dangerous. The client is already exhibiting signs of toxicity; reducing the rate does not remove the magnesium already causing the problem and allows the condition to potentially worsen. Monitoring without active intervention is negligent in this scenario.

Related Concepts: This scenario integrates knowledge of obstetric nursing (preterm labor management), pharmacology (MgSO4 actions and toxicity), and emergency response. Nurses must monitor for the "four D's" of magnesium toxicity: Decreased DTRs, Diuresis (early sign), Diplopia (blurred vision), and Dyspnea. Respiratory arrest and cardiac arrest are the ultimate risks.

Nursing Clinical Practice Guide Clinical Scenario: You are the nurse on the labor and delivery unit. Your patient, Ms. Jones, is on a magnesium sulfate drip for preterm labor. During your hourly assessment, you note her speech is slurred, she complains of profound weakness, her respiratory rate has dropped to 10 breaths/minute, and you are unable to elicit her patellar (knee-jerk) reflex.

Nursing Intervention Strategy: 1. Immediate Action (ABCs): Stop the magnesium sulfate infusion immediately at the pump and clamp the IV line. Call for help (activate the rapid response team or call the physician stat). Assess airway, breathing, and circulation. Prepare to administer oxygen and assist with ventilation if needed. 2. Administer Antidote: While another nurse calls the provider for the order, you prepare calcium gluconate (typically 1 gram IV over 3 minutes). Have it ready at the bedside. In many protocols, this is a standing order for confirmed MgSO4 toxicity. 3. Monitoring & Support: Continuously monitor vital signs, oxygen saturation, and level of consciousness. Prepare for possible intubation if respiratory status deteriorates. Obtain stat labs: magnesium level, electrolytes, and renal function tests (BUN, creatinine). 4. Documentation: Precisely document the time the infusion was stopped, the patient's assessment findings, all interventions performed (including calcium gluconate administration), the provider notified, and the patient's response.

Patient Safety and Precautions: Magnesium sulfate is a high-alert medication. Always use an infusion pump. Before and during infusion, strictly monitor: Deep Tendon Reflexes (DTRs) (should be present, loss is an early sign of toxicity), Respiratory Rate (must be >12 breaths/min), and Urine Output (must be >30 mL/hr, as Mg is excreted renally). Know your facility's protocol for magnesium sulfate administration and toxicity management.

Nursing Procedure & Medication Flow MgSO4 Monitoring Procedure:

• Baseline: Assess and document DTRs, respiratory rate, level of consciousness, and oxygen saturation before starting infusion.
• Ongoing: Monitor DTRs, respiratory rate, and level of consciousness hourly. Monitor urine output hourly via Foley catheter.
• Lab Monitoring: Check serum magnesium levels per protocol (e.g., every 6 hours). Therapeutic range for tocolysis/neuroprotection is typically 4-8 mg/dL. Signs of toxicity often appear at levels >8-10 mg/dL.
• Antidote Administration: Calcium gluconate 1 gm (10 mL of 10% solution) IV push slowly over 3 minutes. Monitor for bradycardia and IV site irritation during administration.

A Word from Your Senior Nurse "Magnesium sulfate is a powerful tool in our obstetric toolkit, but we must respect it. Your vigilant assessment is the patient's primary defense against toxicity. Don't just check the boxes—truly *assess* that reflex, *listen* to the quality of her breath, and *engage* her in conversation to check her mentation. When you see those red flags—weakness, slow breathing, lost reflexes—you don't wait, you don't just turn down the pump. You act decisively to protect your patient's life. This kind of critical thinking and rapid intervention is exactly what the NCLEX tests and what real nursing demands."