What is the treatment for an asthma exacerbation?

Treatment of Asthma Exacerbation

Immediately administer oxygen to maintain SaO₂ >90% (>95% in pregnancy or heart disease), nebulized albuterol 2.5-5 mg every 20 minutes for 3 doses, and oral prednisone 40-60 mg (or 1-2 mg/kg/day in children, max 60 mg) within the first 15-30 minutes. 1, 2, 3

Initial Assessment and Severity Classification

Assess severity rapidly using symptoms, vital signs, and peak expiratory flow (PEF) or FEV₁:

• Mild exacerbation: Dyspnea only with activity, PEF ≥70% predicted 2
• Moderate exacerbation: Dyspnea interfering with usual activity, PEF 40-69% predicted 1, 2
• Severe exacerbation: Dyspnea at rest, PEF <40% predicted, respiratory rate >25/min, heart rate >110/min, inability to complete sentences 1, 2
• Life-threatening features: PEF <33% predicted, silent chest, cyanosis, confusion, altered mental status, PaCO₂ ≥42 mmHg, feeble respiratory effort 1, 2, 3

Primary Treatment Protocol (First 15-30 Minutes)

Oxygen Therapy

• Administer oxygen via nasal cannula or mask to maintain SaO₂ >90% (>95% in pregnant patients or those with heart disease) 1, 2, 3
• Monitor oxygen saturation continuously until clear response to bronchodilator therapy 1, 3

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

Albuterol is the cornerstone of acute treatment for all asthma exacerbations. 1, 2, 3

Nebulizer dosing (preferred for moderate-severe exacerbations):

• Adults: 2.5-5 mg every 20 minutes for 3 doses, then 2.5-10 mg every 1-4 hours as needed 1, 2, 3
• Children: 2.5-5 mg every 20 minutes for 3 doses 1, 3
• For severe exacerbations (PEF <40%), consider continuous nebulization 1, 2

MDI with spacer dosing (equally effective when properly administered):

• Adults: 4-12 puffs every 20 minutes for up to 3 doses 1, 3
• Children: 4-8 puffs every 20 minutes for 3 doses 1

Systemic Corticosteroids (Critical Early Intervention)

Administer systemic corticosteroids immediately for all moderate-to-severe exacerbations—early administration reduces hospitalization rates. 1, 2, 3

Oral route is preferred (as effective as IV and less invasive):

• Adults: Prednisone 40-60 mg orally in single or divided doses 1, 2, 3
• Children: Prednisone 1-2 mg/kg/day (maximum 60 mg/day) 1, 2, 3
• Alternative for children: Dexamethasone 0.3-0.6 mg/kg (max 12-16 mg) for 1-2 days 2

IV corticosteroids (only if patient cannot tolerate oral):

• Hydrocortisone 200 mg IV every 6 hours 1
• Methylprednisolone 1-2 mg/kg IV 1

Duration: 5-10 days for outpatient "burst" therapy; no tapering necessary for courses <10 days 1

Reassessment at 15-30 Minutes

Measure PEF or FEV₁, 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

Adjunctive Therapies for Moderate-to-Severe Exacerbations

Ipratropium Bromide (Anticholinergic)

Add ipratropium bromide to albuterol for ALL moderate-to-severe exacerbations—this combination reduces hospitalizations, particularly in severe airflow obstruction. 1, 2, 3

• Nebulizer: 0.5 mg every 20 minutes for 3 doses, then as needed 1, 2, 3
• MDI: 8 puffs every 20 minutes for 3 doses, then as needed 1, 3

Magnesium Sulfate (For Severe Refractory Cases)

Consider IV magnesium sulfate for severe exacerbations not responding to initial therapy or life-threatening exacerbations. 1, 2, 3

• Adults: 2 g IV over 20 minutes 1, 2, 3
• Children: 25-75 mg/kg (maximum 2 g) IV over 20 minutes 1

Common Pitfalls and What to Avoid

• Do NOT administer sedatives of any kind—they can precipitate respiratory failure 1
• Do NOT use methylxanthines (theophylline)—increased side effects without superior efficacy 1
• Do NOT routinely prescribe antibiotics unless strong evidence of bacterial infection (pneumonia, sinusitis) 1, 3
• Do NOT delay intubation once deemed necessary—perform semi-electively before respiratory arrest 1
• Do NOT underestimate severity—patients, relatives, and physicians often underestimate severity due to failure to make objective measurements 1
• Avoid aggressive hydration in older children and adults (may be appropriate for infants/young children) 1

Hospital Admission Criteria

Admit to hospital if any of the following persist after initial treatment (60-90 minutes):

• Any life-threatening features (confusion, silent chest, cyanosis, PaCO₂ ≥42 mmHg) 1, 2, 3
• PEF <33% predicted after initial treatment 1, 2
• Features of severe asthma persist after 1 hour of intensive treatment 1, 2
• Lower threshold for admission if: recent nocturnal symptoms, recent hospital admission, previous severe attacks, poor social circumstances, or presentation in afternoon/evening 1, 2

Discharge Criteria (After Stabilization)

Patients may be discharged when:

• PEF reaches ≥70% of predicted or personal best 1, 3
• Symptoms have stabilized or returned to normal function 1
• Oxygen saturation stable on room air 3
• Patient has appropriate maintenance therapy and written asthma action plan 1

Discharge medications:

• Continue oral corticosteroids for 5-10 days (no taper needed) 1
• Initiate or increase inhaled corticosteroids 1
• Ensure adequate supply of albuterol 1
• Arrange follow-up with primary care within 1 week 1

Monitoring for Impending Respiratory Failure

Watch for signs requiring immediate escalation or intubation:

• Inability to speak 1
• Altered mental status 1, 2
• Worsening fatigue despite treatment 1
• PaCO₂ ≥42 mmHg (normal or elevated CO₂ in a breathless asthmatic is ominous) 1
• Silent chest on auscultation 1, 2

Consider heliox (helium-oxygen mixture) before intubation in severe refractory cases. 4