What is the recommended treatment for an asthma exacerbation?

Asthma Exacerbation Treatment

For acute asthma exacerbations, immediately administer oxygen to maintain SaO₂ >90%, repetitive albuterol (2.5-5 mg nebulized every 20 minutes for 3 doses), and systemic corticosteroids (prednisone 40-60 mg orally for adults) within the first 15-30 minutes, adding ipratropium bromide for moderate-to-severe cases. 1

Initial Assessment and Severity Classification

Classify severity immediately using objective measures: 1

• Mild exacerbation: Dyspnea only with activity, PEF ≥70% predicted, usually managed at home 2
• Moderate exacerbation: Dyspnea interfering with usual activity, PEF 40-69% predicted, typically requires ED visit 2
• Severe exacerbation: Dyspnea at rest interfering with conversation, PEF <40% predicted, respiratory rate >25/min, heart rate >110/min, inability to complete sentences 2, 1
• Life-threatening features: PEF <33% predicted, silent chest, cyanosis, altered mental status, PaCO₂ ≥42 mmHg, bradycardia, exhaustion 1

Critical pitfall: Severity is frequently underestimated by patients, families, and clinicians due to failure to obtain objective measurements—always measure PEF or FEV₁. 1

Primary Treatment Algorithm

First 15-30 Minutes 1

Oxygen therapy: 1, 3

• Administer via nasal cannula or mask to maintain SaO₂ >90% (>95% in pregnant patients or those with heart disease)
• Monitor continuously until clear response to bronchodilators occurs

Short-acting beta-agonist (albuterol): 1, 4

• Nebulizer: 2.5-5 mg every 20 minutes for 3 doses, then 2.5-10 mg every 1-4 hours as needed
• MDI with spacer: 4-8 puffs every 20 minutes for up to 3 doses (equally effective when properly administered)
• For severe exacerbations (PEF <40%), consider continuous nebulization at 10-15 mg/hour 3

Systemic corticosteroids (administer immediately, not "after trying bronchodilators first"): 1, 3

• Adults: Prednisone 40-60 mg orally in single or divided doses
• Children: 1-2 mg/kg/day orally (maximum 60 mg/day)
• Oral administration is as effective as IV and less invasive 1, 5
• Anti-inflammatory effects take 6-12 hours to manifest, so early administration is critical 6

Adjunctive Ipratropium Bromide 1, 3

Add for all moderate-to-severe exacerbations: 1

• Dosing: 0.5 mg via nebulizer or 8 puffs via MDI every 20 minutes for 3 doses, then as needed
• Reduces hospitalizations, particularly in patients with severe airflow obstruction
• Provides clinically meaningful improvement in lung function when combined with beta-agonists 6

Reassessment Protocol

At 15-30 minutes after initial treatment: 1

• Measure PEF or FEV₁
• Assess symptoms, vital signs, and oxygen saturation
• Response to treatment is a better predictor of hospitalization need than initial severity 1, 3

At 60-90 minutes (after 3 doses of bronchodilator): 1

• Good response (PEF ≥70% predicted, minimal symptoms, stable on room air): Consider discharge with 5-10 day oral corticosteroid course 1
• Incomplete response (PEF 40-69%, persistent symptoms): Continue intensive treatment, admit to hospital ward 1
• Poor response (PEF <40%, severe symptoms persist): Admit to hospital, consider ICU if life-threatening features present 1

Severe or Refractory Exacerbations

Intravenous Magnesium Sulfate 1, 6

Indications: 6

• Life-threatening exacerbations
• Severe exacerbations (FEV₁ or PEF <40%) remaining after 1 hour of intensive conventional treatment
• Greatest benefit in patients with FEV₁ <20% predicted

Dosing: 1, 6

• Adults: 2 g IV over 20 minutes
• Children: 25-75 mg/kg (maximum 2 g) IV over 20 minutes
• Administer as adjunct to standard therapy, not replacement
• Side effects are minor (flushing, light-headedness) 6

Warning Signs of Impending Respiratory Failure 1

Monitor for: drowsiness, confusion, inability to speak, worsening fatigue, silent chest, PaCO₂ ≥42 mmHg

• Do not delay intubation once deemed necessary—perform semi-electively before respiratory arrest 1
• Consider ICU transfer immediately for patients with these features

Hospital Admission Criteria 1

Immediate hospital referral required for: 1

• Life-threatening features (confusion, silent chest, cyanosis, PEF <33%)
• Features of severe attack persisting after initial treatment
• PEF <50% predicted after 1-2 hours of treatment

Lower threshold for admission: 2

• Patients presenting afternoon/evening
• Recent nocturnal symptoms
• Previous severe attacks
• Poor social circumstances or concerning psychosocial factors

Discharge Planning 1, 3

Discharge criteria: 1

• PEF ≥70% of predicted or personal best
• Symptoms minimal or absent
• Oxygen saturation stable on room air
• Patient stable for 30-60 minutes after last bronchodilator dose

Discharge medications: 1

• Continue oral corticosteroids for 5-10 days (no taper needed for courses <10 days) 1, 7, 8
• Initiate or continue inhaled corticosteroids
• Provide written asthma action plan
• Review inhaler technique
• For high-risk non-adherent patients, consider IM depot corticosteroid injection 1

Follow-up: 1

• Primary care within 1 week
• Specialist clinic within 4 weeks

Critical Pitfalls to Avoid 1

• Never administer sedatives of any kind to patients with acute asthma
• Do not delay corticosteroids—give immediately, not after "trying bronchodilators first"
• Avoid bolus aminophylline in patients already taking oral theophyllines
• Do not prescribe antibiotics unless strong evidence of bacterial infection (pneumonia, sinusitis)
• Avoid methylxanthines (theophylline)—increased side effects without superior efficacy 1
• Do not recommend aggressive hydration in older children/adults, chest physiotherapy, or mucolytics 1