What is the recommended management for asthma exacerbations?

Asthma Exacerbation Management

Immediately administer oxygen to maintain SaO₂ >90% (>95% in pregnant patients or those with heart disease), albuterol 2.5-5 mg via nebulizer or 4-8 puffs via MDI with spacer every 20 minutes for 3 doses, and oral prednisone 40-60 mg (adults) or 1-2 mg/kg/day for children within the first 15-30 minutes of presentation. 1, 2, 3

Initial Assessment and Severity Classification

Classify severity immediately upon presentation using objective measures:

• 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
• Severe exacerbation: Dyspnea at rest, PEF <40% predicted, speaks in words, respiratory rate >25/min, heart rate >110/min 1, 2
• Life-threatening features: PEF <33% predicted, silent chest, cyanosis, altered mental status, PaCO₂ ≥42 mmHg, inability to speak, exhaustion 1, 2, 3

Critical pitfall: Severity is often underestimated by patients, families, and physicians due to failure to make objective measurements—always measure PEF or FEV₁ before initiating treatment. 1

Primary Treatment Algorithm (First 15-30 Minutes)

Oxygen Therapy

• Administer via nasal cannula or mask to maintain SaO₂ >90% (>95% in pregnant patients or those with heart disease) 1, 2
• Monitor oxygen saturation continuously until clear response to bronchodilator therapy 1

Bronchodilator Therapy

• Albuterol (first-line): 2.5-5 mg via nebulizer OR 4-8 puffs via MDI with spacer every 20 minutes for 3 doses 1, 2, 3
• Nebulizer and MDI with spacer are equally effective when properly administered 1
• After initial 3 doses (60-90 minutes), continue 2.5-10 mg every 1-4 hours as needed 1

Systemic Corticosteroids (Critical—Do Not Delay)

• 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
• Oral administration is as effective as IV and less invasive 1
• Early administration reduces hospitalization rates—this is a high-priority intervention 3

Reassessment at 15-30 Minutes

Measure and document:

• PEF or FEV₁ 1, 2
• Oxygen saturation 1
• Respiratory rate, heart rate, accessory muscle use 1
• Ability to speak in sentences 2

Response to treatment is a better predictor of hospitalization need than initial severity. 1

Adjunctive Therapies for Moderate-to-Severe Exacerbations

Ipratropium Bromide

• Add to albuterol for all moderate-to-severe exacerbations (PEF <70% predicted) 1, 2, 3
• Dosing: 0.5 mg via nebulizer OR 8 puffs via MDI every 20 minutes for 3 doses, then as needed 1, 2
• Reduces hospitalizations, particularly in patients with severe airflow obstruction 1, 2

Magnesium Sulfate (Severe/Refractory Cases)

• Consider for severe exacerbations not responding to initial therapy or life-threatening features 1, 2, 3
• Adults: 2 g IV over 20 minutes 1, 2
• Children: 25-75 mg/kg (maximum 2 g) 1

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

Good Response (PEF ≥70% predicted, minimal symptoms)

• Observe for 30-60 minutes after last bronchodilator dose to ensure stability 4
• Discharge if stable with PEF ≥70% predicted and symptoms minimal or absent 4, 1

Incomplete Response (PEF 50-69% predicted)

• Continue bronchodilators every 1-4 hours 1
• Continue systemic corticosteroids 1
• Consider extended observation or admission based on risk factors for asthma-related death 4

Poor Response (PEF <50% predicted, severe symptoms persist)

• Consider continuous nebulization of albuterol 1
• Administer IV magnesium sulfate if not already given 1, 2
• Obtain chest X-ray to exclude pneumothorax, consolidation, or pulmonary edema 1
• Prepare for possible hospital admission 2

Hospital Admission Criteria

Admit patients with:

• Life-threatening features at any point 2
• Features of severe exacerbation persisting after initial treatment 2
• PEF <50% predicted after 1-2 hours of treatment 4
• Lower threshold for admission if: recent nocturnal symptoms, previous severe attacks, afternoon/evening presentation, poor social circumstances 2

Recognition of Impending Respiratory Failure

Do not delay intubation once deemed necessary—perform semi-electively before respiratory arrest. 1

Monitor for:

• Inability to speak 1
• Altered mental status or exhaustion 1
• Intercostal retractions with worsening fatigue 1
• PaCO₂ ≥42 mmHg (normal or elevated CO₂ in a breathless asthmatic is life-threatening) 1, 2
• Silent chest, bradycardia, hypotension 2

Discharge Planning (When Stable)

Discharge Criteria

• PEF ≥70% predicted or personal best 4, 1
• Symptoms minimal or absent 4
• Oxygen saturation stable on room air 2
• Patient observed for 30-60 minutes after last bronchodilator dose 4

Discharge Medications

• Continue oral corticosteroids for 5-10 days (no taper needed for courses <10 days) 1, 2
• Initiate or continue inhaled corticosteroids—consider starting at discharge if not already prescribed 4, 1
• Provide rescue inhaler (albuterol) with spacer 1
• For patients at high risk of non-adherence, consider IM depot corticosteroid injection 4

Patient Education and Follow-up

• Provide written asthma action plan 4, 1
• Review inhaler technique 4
• Arrange follow-up with primary care within 1 week 1
• Arrange specialist follow-up within 4 weeks 1

Critical Pitfalls to Avoid

• Never delay systemic corticosteroids in moderate-to-severe exacerbations 3
• Never administer sedatives of any kind during acute exacerbation 1
• Avoid SABA monotherapy without inhaled corticosteroids for maintenance—this increases exacerbation risk and asthma-related deaths 3
• Do not use methylxanthines (theophylline)—increased side effects without superior efficacy 1
• Avoid aggressive hydration in older children and adults 1
• Do not routinely prescribe antibiotics unless strong evidence of bacterial infection (pneumonia, sinusitis) 1, 2
• Do not use chest physiotherapy or mucolytics 1

Special Considerations

Infants and Young Children

• Assessment depends more on physical examination than objective measurements 2
• Signs of serious distress: accessory muscle use, paradoxical breathing, cyanosis, respiratory rate >60/min 2
• Lack of response to short-acting β₂-agonist therapy indicates need for hospitalization 2

EMS Transport

• Do not delay transport while administering bronchodilator treatment 2
• Maximum 3 bronchodilator treatments during first hour, then 1 per hour during transport 2