A nurse is caring for a 28-year-old primigravida client at 34 weeks gestation who was admitted with severe preeclampsia. The client reports severe headache, visual disturbances, and epigastric pain. Vital signs are BP 170/110 mmHg, pulse 88 bpm, respirations 20/min, temperature 98.6°F. Laboratory results show 3+ proteinuria and elevated liver enzymes. The physician has ordered magnesium sulfate therapy for seizure prophylaxis. What is the priority nursing intervention before initiating magnesium sulfate?
1Check the client's deep tendon reflexes
2Ensure that calcium gluconate is readily available at the bedside✓ 정답
3Insert a Foley catheter to monitor urine output
4Obtain baseline serum magnesium level
해설
Ensuring calcium gluconate availability is the priority as it is the antidote for magnesium toxicity, addressing the most critical safety risk. Other interventions (reflex check, catheter, baseline level) are important but secondary to immediate antidote access.
Core Nursing ExplanationKey Concept Analysis: This question tests the critical nursing priority when initiating magnesium sulfate (MgSO4) therapy for a patient with severe preeclampsia. The core concept is patient safety and risk management for a life-threatening medication side effect. Magnesium sulfate is a central nervous system depressant used to prevent eclamptic seizures. However, its therapeutic range is narrow, and toxicity can lead to respiratory depression, cardiac arrest, and death. The priority before administration is ensuring immediate access to the antidote.
Answer Rationale: Key Point!Calcium gluconate is the specific antidote for magnesium sulfate toxicity. Before starting an infusion of a high-risk medication where toxicity can be rapidly fatal, the nurse's first action is to verify that the life-saving antidote is immediately available at the bedside. This is a fundamental safety check that addresses the greatest potential for harm. While the other options are important components of care, they do not mitigate the immediate, lethal risk posed by the medication itself if toxicity occurs.
Distractor Analysis:
Watch out for confusion! Option 1: Checking deep tendon reflexes (DTRs) is a crucial ongoing assessment during MgSO4 therapy (loss of reflexes is an early sign of toxicity), but it is not the priority action before initiating the infusion. You check reflexes to monitor for toxicity after the infusion has started and you have ensured safety measures are in place.
Option 3: Inserting a Foley catheter is important because urine output is the primary route of magnesium excretion. Monitoring output (Normal Value: at least 30 mL/hr) is essential to assess for impending toxicity. However, this is an implementation step, not the highest-priority safety preparation.
Option 4: Obtaining a baseline serum magnesium level is a correct and standard procedure. However, it does not directly protect the patient from an acute toxic reaction in the way having the antidote ready does. The result also takes time, while the need for the antidote can be immediate.
Related Concepts: This scenario integrates knowledge of obstetric emergencies, pharmacology, and the nursing process. The priority follows the principle of "first, do no harm" and preparing for the worst-case scenario when administering a high-alert medication. Management of severe preeclampsia also focuses on preventing progression to eclampsia (seizures) and HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelets), which is suggested by the client's epigastric pain and elevated liver enzymes.
Concept Summary
Concept
Key Points
Severe Preeclampsia
BP ≥160/110 mmHg, proteinuria, symptoms (headache, visual changes, epigastric pain). Goal: prevent seizures (eclampsia) and deliver fetus.
Magnesium Sulfate (MgSO4)
Drug of choice for seizure prophylaxis. CNS depressant. Narrow therapeutic window.
MgSO4 Toxicity Signs
Loss of DTRs (first sign), Respiratory rate < 12/min, Urine output < 30 mL/hr, somnolence, cardiac arrest.
Calcium Gluconate
Antidote for MgSO4 toxicity. Must be at bedside before infusion starts.
Hold MgSO4, prepare to administer calcium gluconate, support ventilation.
Urine Output
≥30 mL/hr
< 30 mL/hr
Hold MgSO4, assess fluid status, notify provider.
Anatomy, Physiology & Pharmacology Points
Pathophysiology: Preeclampsia involves vasospasm, endothelial damage, and increased vascular permeability, leading to hypertension, proteinuria, and end-organ dysfunction (brain, liver, kidneys).
Drug Mechanism: Magnesium sulfate acts as a CNS depressant and neuromuscular blocker, reducing neuronal excitability and preventing seizure activity.
Antidote Mechanism: Calcium gluconate works by competitively antagonizing magnesium at the neuromuscular junction, reversing respiratory depression and cardiac effects.
Memory Tips
Acronym for MgSO4 Toxicity Assessment: "Reflexes, Respirations, Renal (output)" – the 3 Rs.
Priority Rule: "Antidote Before the Dose." For any high-risk medication with a specific antidote (e.g., Naloxone for opioids, Flumazenil for benzodiazepines), ensuring the antidote is available is a top-tier priority.
High-Frequency NCLEX Topics
This integrates several high-yield NCLEX areas: obstetric emergencies, medication safety and administration (high-alert medications), priority-setting (Maslow's hierarchy, safety first), and nursing interventions for specific drug therapies. Expect questions on signs of MgSO4 toxicity and appropriate nursing responses.
Watch Out for Question Variations!
Instead of "before initiating," the question could ask: "Which finding requires immediate discontinuation of the MgSO4 infusion?" Answer: Respiratory depression (<12/min) or absent reflexes.
The question could focus on patient education: "What should the nurse teach the client about reasons to call the nurse immediately?" Answer: Blurred vision, severe headache, epigastric pain, decreased fetal movement (signs of worsening preeclampsia).
It could be a pharmacology calculation question: "The order is for 4 grams MgSO4 in 250 mL NS to infuse over 30 minutes. What is the infusion rate in mL/hr?" (Answer: 500 mL/hr).
Nursing Clinical Practice GuideClinical Scenario: You are the nurse on the Labor & Delivery unit. A 28-year-old patient, G1P0 at 34 weeks, is admitted with a BP of 170/110, complaining of a "crushing" headache and seeing spots. She rates her epigastric pain as 8/10. The provider diagnoses severe preeclampsia and orders a magnesium sulfate bolus followed by a maintenance infusion.
Nursing Intervention Strategy:
Immediate Safety Preparation (Before Starting IV): Confirm an ampule of calcium gluconate 1 gram/10 mL is in the patient's bedside medication drawer or crash cart. Ensure you have the correct IV tubing and pump.
Baseline Assessment & Setup: Perform a full assessment: neurologic (DTRs, clonus), respiratory, and cardiovascular. Insert a Foley catheter for strict I&O. Obtain ordered labs (CBC, liver enzymes, creatinine, Mg level).
During Infusion – Vigilant Monitoring:
Every 1 hour: Assess DTRs, respiratory rate and effort, level of consciousness.
Continuous: Monitor fetal heart rate and uterine activity.
Monitor for signs of worsening preeclampsia (increased headache, visual changes, pain).
If Toxicity is Suspected: STOP THE INFUSION. Maintain airway, breathing, circulation. Notify provider STAT and prepare to administer calcium gluconate as ordered (typically 1 gram IV push over 3 minutes).
Medication Cautions: Never administer MgSO4 as an IV push. It must be diluted and given via controlled infusion pump. The bolus is typically given over 15-30 minutes.
Key Monitoring Points: The "3 Rs" (Reflexes, Respirations, Renal output) are non-negotiable. A silent room is best for checking patellar and biceps reflexes.
Nursing Procedure & Medication FlowMgSO4 Administration Checklist:
1. Key Point! Verify calcium gluconate is at bedside.
2. Obtain baseline vital signs, DTRs, labs.
3. Insert Foley catheter, connect to urimeter.
4. Set up IV pump with secondary line for MgSO4.
5. Administer loading dose (e.g., 4-6 g over 15-30 min) per protocol.
6. Start maintenance infusion (e.g., 1-2 g/hr).
7. Document all assessments, infusion start time, and pump settings.
8. Perform and document hourly monitoring (RR, DTRs, LOC, UOP).
A Word from Your Senior Nurse
"Managing a patient on magnesium sulfate is one of the most high-stakes, vigilant nursing responsibilities in obstetrics. It's a perfect example of how our knowledge directly saves lives. That vial of calcium gluconate isn't just a medication; it's a promise of safety to your patient. In the real world, you'll feel the weight of that responsibility. On the NCLEX, they test if you understand that weight. Always think: What is the worst thing that could happen with this intervention? And how do I, as the nurse, prepare for it first? That mindset will guide you to the correct priority answer every time."