What are the nursing actions for patients receiving magnesium sulfate (MgSO4)?

Nursing Actions for Magnesium Sulfate Administration

Nursing actions for magnesium sulfate administration should focus on careful monitoring of therapeutic levels, vital signs, and early detection of toxicity to prevent serious complications.

Dosage and Administration

Pre-eclampsia/Eclampsia

• Loading dose: 4-5g IV in 250mL of 5% Dextrose or 0.9% Sodium Chloride over 20 minutes 1
• Maintenance dose: 1-2g/hour by continuous IV infusion 1
  • For overweight patients (BMI ≥25 kg/m²), 2g/hour maintenance may be more effective in achieving therapeutic levels 2
• Alternative regimen (Pritchard): 14g loading dose (4g IV + 5g IM in each buttock), followed by 5g IM every 4 hours 3

Magnesium Deficiency

• Mild deficiency: 1g (8.12 mEq) IM every 6 hours for 4 doses 1
• Severe deficiency: Up to 250mg/kg IM within 4 hours or 5g IV over 3 hours 1

Asthma

• 2g IV over 20 minutes for severe asthma exacerbations 4

Essential Monitoring

Before Administration

• Obtain baseline vital signs
• Check deep tendon reflexes
• Assess respiratory rate and depth (should be >12/min)
• Obtain baseline serum magnesium, renal function tests
• Ensure urine output is adequate (>30mL/hour) 3, 1

During Administration

• Monitor vital signs every 15-30 minutes during loading dose, then hourly
• Check deep tendon reflexes hourly (first sign of toxicity is loss of patellar reflex at 3.5-5 mmol/L) 5
• Monitor respiratory rate (respiratory depression occurs at 5-6.5 mmol/L) 5
• Measure urine output hourly (should remain >30mL/hour)
• Assess for signs of magnesium toxicity:
  • Loss of deep tendon reflexes
  • Respiratory depression
  • Hypotension
  • Flushing, sweating
  • Cardiac conduction abnormalities 4, 5
• Monitor serum magnesium levels:
  • Therapeutic range: 1.8-3.0 mmol/L (4.8-8.4 mg/dL) 5, 6
  • Check levels 4 hours after initiation and then every 6 hours 7

Emergency Preparedness

• Keep calcium gluconate (10%) readily available as antidote for magnesium toxicity 4
• Have emergency equipment accessible (airway management supplies)
• Document location of emergency medications and equipment
• Be prepared to stop infusion immediately if signs of toxicity appear 4, 8

Fluid Management

• Limit total fluid intake to 60-80 mL/hour during labor for pre-eclamptic patients 3
• Monitor for signs of pulmonary edema
• Maintain accurate intake and output records

Patient Education and Comfort

• Explain sensations patient may experience (feeling hot, flushed)
• Position patient for comfort and safety
• Implement seizure precautions for pre-eclamptic patients
• Explain purpose and importance of frequent monitoring

Special Considerations

• Use with caution in patients with renal insufficiency; maximum dosage should not exceed 20g/48 hours with frequent monitoring 4
• Monitor more frequently in overweight patients as they may require higher maintenance doses 2
• For patients receiving magnesium for >5-7 days during pregnancy, monitor for potential fetal abnormalities 1
• Avoid concurrent use with neuromuscular blocking agents due to risk of excessive neuromuscular blockade 4

Documentation

• Document all assessments, medication administration, and patient response
• Record vital signs, deep tendon reflexes, respiratory status, and urine output
• Document serum magnesium levels and any interventions for abnormal values
• Note patient education provided

By following these structured nursing actions, healthcare providers can safely administer magnesium sulfate while minimizing risks of toxicity and optimizing therapeutic outcomes.