What is the recommended management for asthma exacerbation in pregnancy?

Management of Asthma Exacerbation in Pregnancy

The management of asthma exacerbation during pregnancy should follow the same aggressive approach as in non-pregnant patients, with albuterol as the preferred short-acting beta-agonist and systemic corticosteroids when indicated, as inadequate control of asthma poses greater risks to both mother and fetus than the medications used to treat it. 1

Initial Assessment and Treatment

Home Management

• For mild exacerbations:
  • Albuterol (preferred SABA during pregnancy) via:
    • MDI: 4-8 puffs every 20 minutes for 3 doses, then every 1-4 hours as needed 1
    • Nebulizer: 0.15 mg/kg (minimum 2.5 mg) every 20 minutes for 3 doses, then 0.15-0.3 mg/kg up to 10 mg every 1-4 hours as needed 2, 1
  • Assess response to treatment using symptoms and peak flow measurements
  • If PEF remains <70% of personal best after initial treatment, proceed to emergency care

Emergency Department Management

• Continue albuterol treatments as above
• Add ipratropium bromide if needed:
  • Nebulizer: 0.25 mg every 20 minutes for 3 doses, then every 2-4 hours 1
  • MDI: 4-8 puffs as needed 1
• Oxygen therapy to maintain maternal SpO2 ≥95% to ensure adequate fetal oxygenation 2
• Systemic corticosteroids for moderate to severe exacerbations:
  • Prednisone: 40-60 mg/day for outpatient treatment for 3-10 days 2, 1
  • For severe exacerbations: 120-180 mg/day in 3-4 divided doses for 48 hours, then 60-80 mg/day until PEF reaches 70% of predicted or personal best 2

Monitoring During Exacerbation

• Frequent assessment of:
  • Respiratory rate, heart rate, oxygen saturation
  • Peak expiratory flow (PEF) or FEV1
  • Fetal heart rate monitoring for severe exacerbations or those requiring hospitalization
• Serial ultrasound examinations starting at 32 weeks gestation for women with suboptimally controlled asthma 2, 1
• Monitor for signs of maternal fatigue, which may indicate impending respiratory failure

Important Considerations

Medication Safety

• Albuterol has the most extensive safety data among short-acting beta-agonists in pregnancy 2, 1
• Short courses of systemic corticosteroids are considered safe and the benefits of controlling severe asthma exacerbations outweigh potential risks 1
• Inhaled corticosteroids should be continued during exacerbations if already part of maintenance therapy 2, 1

Maternal and Fetal Risks

• Uncontrolled asthma and exacerbations during pregnancy are associated with:
  • Maternal risks: preeclampsia, gestational hypertension 1
  • Fetal risks: hypoxemia, low birth weight, preterm birth, increased perinatal mortality 1, 3
• Up to 45% of pregnant women with asthma may experience exacerbations requiring medical intervention 4
• Exacerbations are associated with poor perinatal outcomes including low birth weight and preterm delivery 4, 5

Post-Exacerbation Management

1. Review and adjust maintenance therapy:

   • Ensure appropriate inhaled corticosteroid dosing
   • Consider budesonide as the preferred ICS due to extensive safety data 2, 1
   • If already well-controlled on another ICS, continue it rather than switching 1

2. Provide written asthma action plan specific for pregnancy 2

3. Schedule follow-up within 1-2 weeks:

   • Monthly evaluation of asthma symptoms and pulmonary function during pregnancy is recommended 1
   • Consider home peak flow monitoring to detect early signs of exacerbation 1

4. Address contributing factors:

   • Identify and control allergens and irritants, particularly tobacco smoke 2
   • Manage comorbid conditions like rhinitis 5
   • Address medication adherence issues 3, 5

Prevention of Future Exacerbations

• Maintain regular 4-week asthma reviews during pregnancy 4
• Consider treatment adjustment using markers of eosinophilic inflammation (FeNO) which has been shown to reduce exacerbations in pregnancy 4
• Involve a multidisciplinary team including obstetrical care providers 1
• Educate about the importance of medication adherence during pregnancy 3

Hospitalization Criteria

• Consider hospitalization for:
  • Failure to respond to initial emergency treatment
  • PEF or FEV1 <70% of predicted after initial treatment
  • Persistent hypoxemia (SpO2 <95% on room air)
  • History of severe asthma requiring intubation
  • Presence of high-risk comorbidities

Remember that it is safer for pregnant women with asthma to be treated with appropriate asthma medications than for them to have uncontrolled symptoms and exacerbations 2.