What is the recommended treatment for an asthma exacerbation?

Treatment of Asthma Exacerbation

For acute asthma exacerbations, immediately administer oxygen to maintain saturation >90% (>95% in pregnant patients or those with heart disease), give albuterol 2.5-5 mg via nebulizer or 4-8 puffs via MDI with spacer every 20 minutes for 3 doses, and start oral prednisone 40-60 mg within the first hour—this combination forms the foundation of treatment for all moderate to severe exacerbations. 1, 2

Initial Assessment and Severity Classification

Assess severity immediately using objective measures rather than relying on subjective assessment, as severity is frequently underestimated by patients, families, and clinicians: 2

• Mild exacerbation: Dyspnea only with activity, PEF ≥70% predicted, normal speech 1
• Moderate exacerbation: Dyspnea interfering with usual activity, PEF 40-69% predicted, speaks in phrases 1, 2
• Severe exacerbation: Dyspnea at rest, PEF <40% predicted, respiratory rate >25 breaths/min, heart rate >110 beats/min, inability to complete sentences in one breath 1, 2
• Life-threatening features: PEF <33% predicted, silent chest, cyanosis, altered mental status, PaCO₂ ≥42 mmHg, bradycardia, hypotension, exhaustion, confusion 1, 2

Primary Treatment Protocol

Oxygen Therapy

Administer supplemental oxygen immediately via nasal cannula or mask to maintain oxygen saturation >90% (>95% in pregnant patients or those with heart disease), and monitor continuously until clear response to bronchodilator therapy occurs. 1, 3

Short-Acting Beta-Agonist (First-Line Treatment)

Albuterol is the most effective therapy for rapid reversal of airflow obstruction: 4, 1

• Nebulizer dosing: 2.5-5 mg every 20 minutes for 3 doses, then 2.5-10 mg every 1-4 hours as needed 1, 2
• MDI with spacer dosing: 4-8 puffs every 20 minutes for up to 3 doses, then as needed 1, 2
• For severe exacerbations (PEF <40%): Consider continuous nebulization rather than intermittent dosing for more effective bronchodilation 1

Both nebulizer and MDI with spacer are equally effective when properly administered. 2

Systemic Corticosteroids (Critical Early Intervention)

Oral systemic corticosteroids must be administered early—within the first hour of presentation—for all moderate to severe exacerbations, as early administration reduces hospitalization rates. 4, 1, 2

• Adult dosing: Prednisone 40-60 mg orally in single or divided doses 1, 2
• Pediatric dosing: 1-2 mg/kg/day (maximum 60 mg/day) 1, 2
• Duration: 5-10 days for outpatient "burst" therapy; no tapering necessary for courses <10 days 2, 3
• Route: Oral administration is as effective as intravenous and less invasive; use IV hydrocortisone 200 mg only if patient cannot take oral medication 2, 3

Adjunctive Therapies

Ipratropium Bromide (Add for Moderate-to-Severe Exacerbations)

Adding ipratropium bromide to albuterol for all moderate-to-severe exacerbations reduces hospitalizations, particularly in patients with severe airflow obstruction. 1, 2, 5

• Dosing: 0.5 mg via nebulizer or 8 puffs via MDI every 20 minutes for 3 doses, then as needed 1, 2
• Pediatric dosing: 0.25-0.5 mg via nebulizer or 4-8 puffs via MDI every 20 minutes for 3 doses 2

The combination of beta-agonist and ipratropium provides enhanced and prolonged bronchodilation through different mechanisms. 5

Intravenous Magnesium Sulfate (For Severe Refractory Cases)

Consider IV magnesium sulfate for severe exacerbations (FEV₁ or PEF <40%) not responding to initial therapy or with life-threatening features—it is most effective when administered early in the treatment course: 1, 2

• Adult dosing: 2 g IV over 20 minutes 1, 2
• Pediatric dosing: 25-75 mg/kg (maximum 2 g) IV over 20 minutes 2

Magnesium causes relaxation of bronchial smooth muscle, improves pulmonary function, and decreases hospitalization necessity. 2

Reassessment Protocol

Reassess the patient 15-30 minutes after starting treatment—response to treatment is a better predictor of hospitalization need than initial severity. 1, 2

Measure at each reassessment:

• PEF or FEV₁ before and after treatments 1, 2
• Oxygen saturation 1
• Symptoms and vital signs 1, 2

Response Categories After 60-90 Minutes:

Good response (discharge criteria):

• PEF ≥70% predicted or personal best 1, 2
• Minimal or absent symptoms 2
• Oxygen saturation stable on room air 2
• Patient stable for 30-60 minutes after last bronchodilator dose 2

Incomplete response:

• PEF 40-69% predicted with persistent symptoms 2
• Continue intensive treatment and admit to hospital ward 2

Poor response:

• PEF <40% predicted 2
• Admit to hospital; consider ICU if life-threatening features present 2

Hospital Admission Criteria

Immediate hospital admission is required for: 1, 2

• Life-threatening features (PEF <33%, silent chest, altered mental status, PaCO₂ ≥42 mmHg) 1, 2
• Severe exacerbation persisting after 1 hour of intensive treatment 1
• PEF <50% predicted after 1-2 hours of treatment 2

Lower threshold for admission applies to patients presenting in afternoon/evening, those with recent nocturnal symptoms, previous severe attacks, or concerning social circumstances. 2

Critical Pitfalls to Avoid

Never delay corticosteroid administration—do not wait to "try bronchodilators first," as early corticosteroid use is essential for reducing inflammation and preventing hospitalization. 2

Never administer sedatives of any kind to patients with acute asthma exacerbation, as they can precipitate respiratory failure. 1, 2

Avoid theophylline/aminophylline—these agents have erratic pharmacokinetics, significant side effects, and lack evidence of benefit over standard therapy in acute exacerbations. 2, 6, 7

Do not delay intubation once deemed necessary—it should be performed semi-electively before respiratory arrest occurs. 2

Monitor for signs of impending respiratory failure: inability to speak, altered mental status, intercostal retraction, worsening fatigue, silent chest, PaCO₂ ≥42 mmHg. 1, 2

Discharge Planning

Before discharge, ensure: 2

• PEF ≥70% predicted or personal best 2
• Continue oral corticosteroids for 5-10 days (no taper needed for courses <10 days) 2
• Initiate or continue inhaled corticosteroids 2
• Provide written asthma action plan 2
• Review and verify inhaler technique 2
• Arrange follow-up within 1 week 2

Patients at high risk of non-adherence may benefit from IM depot corticosteroid injection at discharge. 2

Special Considerations

Increasing use of short-acting beta-agonists (>2 days per week for symptom relief or >2 nights per month) indicates inadequate asthma control and the need to initiate or intensify anti-inflammatory maintenance therapy. 4

Regular use of SABAs four or more times daily reduces their duration of action, signaling the need to step up long-term control therapy. 2

Antibiotics are not generally recommended unless there is strong evidence of bacterial infection such as pneumonia or sinusitis. 2