What medications are used to manage acute asthma exacerbation in inpatients?

Medications for Acute Asthma Exacerbation Management in Inpatients

The primary treatment for acute asthma exacerbations in inpatients consists of oxygen supplementation, inhaled short-acting beta2-agonists, and systemic corticosteroids, with additional therapies such as ipratropium bromide indicated for severe exacerbations. 1

Primary Medications

Oxygen Therapy

• Administer oxygen through nasal cannulae or mask to maintain oxygen saturation (SaO₂) >90% (>95% in pregnant women and patients with concomitant heart disease) 1
• Monitor oxygen saturation until a clear response to bronchodilator therapy has occurred 1, 2

Short-Acting Beta2-Agonists (SABAs)

• Albuterol is the first-line bronchodilator treatment for all asthma exacerbations 1
• Dosing options:
  • Nebulizer: 2.5-5 mg every 20 minutes for 3 doses, then 2.5-10 mg every 1-4 hours as needed 1
  • MDI with spacer: 4-8 puffs every 20 minutes for 3 doses, then every 1-4 hours as needed 1, 2
• For severe exacerbations (FEV1 or PEF <40% predicted), continuous administration may be more effective than intermittent dosing 1, 3
• Use with caution in patients with cardiovascular disorders, as albuterol may have clinically significant cardiac effects 4

Systemic Corticosteroids

• Early administration of systemic corticosteroids is essential for all moderate-to-severe exacerbations 1, 2
• Oral prednisone (40-60 mg daily in single or divided doses) is preferred unless the patient cannot tolerate oral medication 1, 2
• Intravenous methylprednisolone (1-2 mg/kg/day) can be used when oral administration is not possible 1, 2
• Corticosteroids speed resolution of airflow obstruction and reduce relapse rates 1, 5

Adjunctive Therapies

Ipratropium Bromide

• Add to SABA therapy for moderate-to-severe exacerbations 1, 2
• Dosing options:
  • Nebulizer: 0.5 mg every 20 minutes for 3 doses, then as needed 1, 2
  • MDI: 4-8 puffs every 20 minutes for 3 doses, then every 1-4 hours as needed 1, 2
• The combination of ipratropium with beta-agonists reduces hospitalization rates in severe exacerbations 2, 6

Magnesium Sulfate

• Consider intravenous magnesium sulfate (2 g over 20 minutes) for patients with severe exacerbations that remain severe after 1 hour of intensive conventional treatment 1, 2
• Not recommended for routine use in mild-to-moderate exacerbations 6, 7

Medications Not Routinely Recommended

• Methylxanthines (theophylline, aminophylline): Not recommended for routine use due to potential toxicity and minimal added benefit 1
• Antibiotics: Not routinely indicated unless there is evidence of bacterial infection 1
• Leukotriene receptor antagonists: Insufficient evidence for use in acute exacerbations 1
• Inhaled corticosteroids alone: Not a substitute for systemic corticosteroids in acute treatment 1, 7

Treatment Algorithm

Initial Management (First Hour)

1. Administer oxygen to maintain SaO₂ >90% 1
2. Start SABA treatment (albuterol): 3 treatments at 20-30 minute intervals 1
3. Add ipratropium bromide for moderate-to-severe exacerbations 1, 2
4. Administer systemic corticosteroids within the first hour 1, 2
5. Assess response after initial treatments (symptoms, vital signs, PEF or FEV1) 1, 2

Ongoing Management

• Continue SABA treatment based on response and severity 1
• For severe exacerbations or poor response, consider:
  • Continuous nebulized albuterol 1, 3
  • Intravenous magnesium sulfate 1, 2
• Monitor for signs of impending respiratory failure (inability to speak, altered mental status, worsening fatigue, PaCO2 ≥42 mm Hg) 1

Special Considerations

Potential Adverse Effects

• Beta-agonists may cause tachycardia, tremor, and hypokalemia 4
• Repeated dosing with albuterol has been associated with a 20-25% decline in serum potassium levels 4
• Systemic corticosteroids may cause hyperglycemia, especially in patients with diabetes 4, 8

Monitoring Parameters

• Oxygen saturation (continuous monitoring for severe exacerbations) 1, 2
• PEF or FEV1 before and after treatments 1, 2
• Vital signs, including heart rate and respiratory rate 1
• Clinical assessment of work of breathing and accessory muscle use 1, 3

Remember that response to treatment is a better predictor of the need for hospitalization than the severity at presentation, and early administration of corticosteroids may reduce hospitalization rates 1, 2.