What are the treatment options for asthma exacerbation in pregnancy in the emergency department (ED)?

Treatment of Asthma Exacerbation During Pregnancy in the Emergency Department

The primary treatment for asthma exacerbation during pregnancy in the ED consists of oxygen to maintain SpO2 ≥95%, inhaled short-acting beta-agonists (preferably albuterol), and systemic corticosteroids, as inadequate control of asthma poses greater risks to both mother and fetus than the medications used to treat it. 1

Initial Assessment and Monitoring

• Assess severity of exacerbation based on:

  • Respiratory rate and effort
  • Heart rate
  • Oxygen saturation
  • Peak expiratory flow (PEF) or FEV1
  • Fetal heart rate monitoring for severe exacerbations 1

• Obtain limited laboratory studies only if indicated:

  • Arterial blood gases for patients in severe distress or with FEV1/PEF ≤25% of predicted after initial treatment
  • Chest radiograph only if suspecting complications (pneumonia, pneumothorax, etc.) 2

Primary Treatment Algorithm

1. Oxygen Therapy

• Administer oxygen through nasal cannulae or mask
• Target SpO2 >95% in pregnant women (versus >90% in non-pregnant patients) 2, 1
• Continue monitoring oxygen saturation until clear response to bronchodilator therapy

2. Inhaled Short-Acting Beta2-Agonists

• Albuterol is the preferred agent with most extensive safety data in pregnancy 1, 3
• Dosing options:
  • Nebulizer: 2.5-5 mg every 20 minutes for 3 doses, then 2.5-10 mg every 1-4 hours as needed 2
  • MDI with spacer: 4-8 puffs every 20 minutes for 3 doses, then every 1-4 hours as needed 2
  • For severe exacerbations (FEV1 or PEF <40% predicted): Consider continuous nebulization (10-15 mg/hour) 2

3. Anticholinergics

• Add ipratropium bromide for severe exacerbations 2
• Dosing options:
  • Nebulizer: 0.5 mg every 20 minutes for 3 doses, then as needed 2
  • MDI: 8 puffs every 20 minutes as needed up to 3 hours 2
• Can be mixed with albuterol in same nebulizer 4

4. Systemic Corticosteroids

• Administer early in the course of treatment for moderate to severe exacerbations
• Prednisone 40-60 mg/day in 1-2 divided doses until PEF reaches 70% of predicted or personal best 2, 1
• For severe exacerbations: Consider higher doses (120-180 mg/day) in 3-4 divided doses for 48 hours, then reduce 1
• Continue for 3-10 days total 2, 1

Special Considerations in Pregnancy

• Continue any inhaled corticosteroids that are part of maintenance therapy 1
• Involve obstetrical care providers in management of severe exacerbations 1
• Monitor fetal heart rate in severe exacerbations or those requiring hospitalization 1
• For severe, life-threatening exacerbations unresponsive to initial therapy, do not withhold any medication due to pregnancy concerns 5, 6

Hospitalization Criteria

Consider hospital admission for:

• Failure to respond to initial emergency treatment
• PEF or FEV1 <70% of predicted after initial treatment
• Persistent hypoxemia
• History of severe asthma requiring intubation
• Presence of high-risk comorbidities 1

Discharge Planning

• Ensure PEF or FEV1 is ≥70% of predicted or personal best and maintained for at least 60 minutes 2
• Prescribe:
  • Scheduled short-acting beta-agonist treatments until symptoms resolve
  • Systemic corticosteroids (typically 5-10 day course)
  • Appropriate controller medications 7
• Provide written asthma action plan specific for pregnancy 1
• Arrange follow-up within 1-2 weeks 1

Important Cautions

• Uncontrolled asthma poses greater risks to the fetus than asthma medications 2, 1, 8
• Potential risks of uncontrolled asthma include maternal preeclampsia, gestational hypertension, fetal hypoxemia, low birth weight, preterm birth, and increased perinatal mortality 1, 9
• Monitor for hypokalemia with repeated high-dose beta-agonist therapy 3
• Avoid mixing ipratropium with other drugs (except albuterol) in nebulizer unless drug compatibility is established 4

Remember that aggressive management of asthma exacerbations during pregnancy is essential to prevent maternal and fetal hypoxia, with the goal of rapidly reversing airflow obstruction and preventing recurrence 7.