What is the initial treatment for a patient with bronchial asthma in acute exacerbation?

Initial Treatment for Acute Asthma Exacerbation

Immediately administer three simultaneous interventions: high-flow oxygen to maintain SaO₂ >90%, albuterol 2.5-5 mg via nebulizer (or 4-8 puffs via MDI with spacer) every 20 minutes for 3 doses, and systemic corticosteroids (prednisone 40-60 mg orally or hydrocortisone 200 mg IV). 1, 2, 3

Immediate First-Line Therapy (Within First 5 Minutes)

Oxygen Administration

• Deliver high-flow oxygen at 40-60% via face mask or nasal cannula to maintain SaO₂ >90% in most patients 3
• Target SaO₂ >95% specifically in pregnant patients or those with cardiac disease 1, 2
• Continue continuous oxygen saturation monitoring until clear response to bronchodilator therapy occurs 1, 2

Short-Acting Beta-Agonist (SABA) - Albuterol

• Administer albuterol 2.5-5 mg via nebulizer every 20 minutes for 3 doses in the first hour 1, 2, 3, 4
• Alternative delivery: 4-8 puffs via MDI with spacer every 20 minutes for 3 doses 1, 2, 3
• For severe exacerbations (FEV₁ or PEF <40% predicted), consider continuous nebulization of albuterol at 7.5-10 mg/hour rather than intermittent dosing 1, 2
• After initial 3 doses, continue albuterol 2.5-10 mg every 1-4 hours as needed 1, 2

Systemic Corticosteroids - Critical Early Administration

• Administer systemic corticosteroids immediately, not after "trying bronchodilators first" - this is a critical pitfall to avoid 2
• Adults: Prednisone 40-60 mg orally in single or divided doses 1, 2, 3
• Children: 1-2 mg/kg/day (maximum 60 mg/day) 1, 2
• If unable to take oral medication, give IV hydrocortisone 200 mg 2
• Oral administration is as effective as IV and less invasive - prefer oral route when possible 2

Adjunctive Therapy for Moderate-to-Severe Exacerbations

Ipratropium Bromide

• Add ipratropium bromide 0.5 mg via nebulizer (or 8 puffs via MDI) to albuterol every 20 minutes for 3 doses, then as needed 1, 2, 3, 5
• This combination reduces hospitalizations, particularly in patients with severe airflow obstruction (PEF <40% predicted) 1, 2
• Can be mixed with albuterol in the same nebulizer if used within 1 hour 5

Severity Assessment (Perform Simultaneously with Treatment)

Severe Exacerbation Features

• Inability to complete sentences in one breath 2, 3
• Respiratory rate >25 breaths/min 2, 3
• Heart rate >110 beats/min 2, 3
• PEF <50% of predicted or personal best 2, 3
• Dyspnea at rest 1, 2

Life-Threatening Features Requiring ICU Consideration

• PEF <33% of predicted or personal best 2, 3
• Silent chest, cyanosis, or feeble respiratory effort 2, 3
• Altered mental status, confusion, or drowsiness 2, 3
• Bradycardia or hypotension 2, 3
• PaCO₂ ≥42 mmHg (normal or elevated CO₂ in a breathless patient is ominous) 2, 3

Reassessment Protocol

First Reassessment (15-30 Minutes After Starting Treatment)

• Measure PEF or FEV₁ before and after each treatment 1, 2, 3
• Assess symptoms, vital signs, and oxygen saturation 1, 2, 3
• Response to treatment is a better predictor of hospitalization need than initial severity 1, 2

Second Reassessment (60-90 Minutes - After 3 Doses of Bronchodilator)

• Repeat objective measurements (PEF or FEV₁) 2, 3
• Classify response as good (PEF ≥70% predicted), incomplete (PEF 40-69%), or poor (PEF <40%) 2

Escalation for Severe Refractory Cases

Intravenous Magnesium Sulfate

• Administer magnesium sulfate 2 g IV over 20 minutes for:
  • Life-threatening features present 2, 3
  • Severe exacerbations (FEV₁ or PEF <40%) not responding after 1 hour of intensive treatment 1, 2, 3
• Pediatric dose: 25-75 mg/kg (maximum 2 g) IV over 20 minutes 2
• Most effective when administered early in the treatment course 1, 2

Continuous Albuterol Nebulization

• For patients with severe exacerbations showing inadequate response to intermittent dosing, switch to continuous nebulization 1, 2
• Continue monitoring for signs of impending respiratory failure 1, 2

Critical Pitfalls to Avoid

Medication Errors

• Never administer sedatives of any kind to patients with acute asthma 1, 2
• Avoid methylxanthines (theophylline/aminophylline) - they have erratic pharmacokinetics and significant side effects without superior efficacy 2
• Do not give bolus aminophylline to patients already taking oral theophyllines 2

Assessment Errors

• Severity is frequently underestimated by patients, families, and clinicians due to failure to make objective measurements (PEF or FEV₁) 2, 3
• Do not rely solely on clinical assessment - always obtain objective lung function measurements 2, 3
• Recognize that tachycardia >110 beats/min indicates severe exacerbation, though beta-agonist therapy will further increase heart rate 2
• Bradycardia or hypotension in asthma exacerbation are ominous signs of impending respiratory arrest, not medication effects 2

Treatment Delays

• Do not delay corticosteroid administration - give immediately, not after "trying bronchodilators first" 2
• Do not delay intubation once respiratory failure is deemed imminent, but consider all other treatments (magnesium, continuous albuterol) before resorting to intubation 1, 2

Hospital Admission Criteria

Immediate Hospital Admission Required

• Life-threatening features present (PEF <33%, silent chest, altered mental status, PaCO₂ ≥42 mmHg) 2, 3
• Features of severe attack persisting after initial treatment 2, 3
• PEF <50% predicted after 1-2 hours of treatment 2

Lower Threshold for Admission

• Presentation in afternoon/evening 2
• Recent onset of nocturnal symptoms 2
• Previous severe attacks requiring intubation or ICU admission 1, 2
• Poor adherence or concerning social circumstances 2
• Currently using or recently stopped oral corticosteroids 1

Monitoring for Impending Respiratory Failure

Warning Signs Requiring ICU Transfer

• Inability to speak 1, 2
• Altered mental status, confusion, or drowsiness 1, 2, 3
• Intercostal retraction with worsening fatigue 1, 2
• Silent chest despite severe distress 2, 3
• PaCO₂ ≥42 mmHg or rising 2, 3
• Minimal relief from frequent SABA despite aggressive treatment 2