What is the initial treatment protocol for acute asthma exacerbation?

Acute Asthma Exacerbation Protocol

Immediately administer oxygen to maintain SpO₂ >90% (>95% in pregnant patients or those with heart disease), high-dose albuterol, and systemic corticosteroids within the first 15-30 minutes of presentation. 1, 2

Initial Assessment (First 15 Minutes)

Severity Classification:

• Mild: Dyspnea only with activity, PEF ≥70% predicted, speaks in sentences 1
• Moderate: Dyspnea interfering with usual activity, PEF 40-69% predicted, speaks in phrases 1
• Severe: Dyspnea at rest, PEF <40% predicted, speaks in words, respiratory rate >25/min, heart rate >110/min 1
• Life-threatening: PEF <33% predicted, silent chest, cyanosis, altered mental status, PaCO₂ ≥42 mmHg, inability to speak 3, 1

Immediate Treatment Protocol

First-Line Therapies (Start Simultaneously)

1. Oxygen Therapy:

• Administer via nasal cannula or mask to maintain SpO₂ >90% (>95% in pregnancy/heart disease) 1, 2
• Monitor continuously until clear response to bronchodilators 1, 2

2. Short-Acting Beta-Agonist (Albuterol):

• Nebulizer: 2.5-5 mg every 20 minutes for 3 doses (first hour), then 2.5-10 mg every 1-4 hours as needed 3, 1, 2
• MDI with spacer: 4-8 puffs every 20 minutes for 3 doses (first hour), then as needed 1, 2
• For severe exacerbations (PEF <40%): Consider continuous nebulization 2

3. Systemic Corticosteroids (Administer Early):

• Adults: Prednisone 40-60 mg PO in single or divided doses 3, 1, 2
• Children: 1-2 mg/kg/day PO (maximum 60 mg/day) 1, 2
• Alternative: IV hydrocortisone 200 mg if unable to take oral 1
• Critical point: Clinical benefits may not occur for 6-12 hours, so early administration is essential 4, 5

Add-On Therapy for Moderate-to-Severe Exacerbations

4. Ipratropium Bromide:

• Add to albuterol for all moderate-to-severe exacerbations 3, 1, 2
• Adults: 0.5 mg via nebulizer or 8 puffs via MDI every 20 minutes for 3 doses, then as needed 3, 1, 2
• Children: 0.25-0.5 mg via nebulizer or 4-8 puffs via MDI every 20 minutes for 3 doses 3
• Evidence: Reduces hospitalizations, particularly in severe airflow obstruction 3, 6

Reassessment Protocol

After Initial Treatment (15-30 minutes):

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

Repeat Assessment (60-90 minutes):

• All patients should be reassessed after 3 doses of bronchodilator (60-90 minutes) 3
• Include subjective response, physical findings, and objective measurements 3

Escalation for Severe/Refractory Cases

If inadequate response after initial treatment:

5. Intravenous Magnesium Sulfate:

• Indication: Life-threatening exacerbations or severe exacerbations remaining after 1 hour of intensive treatment 3, 1, 2
• Dose: 2 g IV over 20 minutes 1, 2
• Most effective when administered early 2

6. Monitor for Impending Respiratory Failure:

• Warning signs: Inability to speak, altered mental status, intercostal retractions, worsening fatigue, PaCO₂ ≥42 mmHg 3, 2
• Do not delay intubation once deemed necessary 3

Common Pitfalls to Avoid

• Underestimation of severity: Failure to make objective measurements (PEF/FEV₁) leads to underestimation by patients, relatives, and physicians 1
• Never administer sedatives of any kind during acute exacerbation 1, 2
• Avoid aggressive hydration in older children and adults (may be appropriate for infants/young children with dehydration) 3
• Do not routinely prescribe antibiotics unless strong evidence of bacterial infection (pneumonia, sinusitis) exists 3, 1
• Avoid methylxanthines, chest physiotherapy, and mucolytics 3

Disposition Criteria

Hospital Admission Indicated:

• Life-threatening features persist after initial treatment 1
• PEF remains <50% predicted after treatment 1
• Severe exacerbation features persist after 3 doses of bronchodilators 1

Discharge Criteria:

• PEF >70% predicted or personal best 1
• Symptoms stabilized 1
• Continue oral corticosteroids for 5-10 days (no taper needed for courses <10 days) 1