Systemic Steroid Treatment for Severe Asthma Exacerbations in Adults

Initial Assessment and Classification

Severe asthma exacerbation is characterized by: inability to complete sentences in one breath, respiratory rate >25 breaths/min, PEF <50% of predicted/best, and heart rate >110 beats/min 2
Life-threatening features include: PEF <33% of predicted/best, silent chest, cyanosis, feeble respiratory effort, bradycardia/hypotension, exhaustion, confusion, or coma 2
Arterial blood gas tensions should be measured in severe cases, with normal/high PaCO₂, severe hypoxia (PaO₂ <8 kPa), or low pH indicating life-threatening status 2

The American College of Allergy, Asthma, and Immunology recommends oral prednisone 40-60 mg daily until PEF reaches 70% of predicted or personal best 1
Alternative: IV hydrocortisone 200 mg every 6 hours for patients who are seriously ill or vomiting 2, 3
For outpatient management, a "burst" of 40-60 mg in single or divided doses for a total of 5-10 days 1

Underuse of corticosteroids is associated with increased mortality in asthma 4
Systemic corticosteroids should be administered early in the treatment course, as their anti-inflammatory effects may take 6-12 hours to appear 4

Underestimating the severity of asthma exacerbations, which can lead to inadequate treatment and potentially fatal outcomes 2, 4
Delaying corticosteroid administration, which can lead to poorer outcomes 4
Using sedatives, which are contraindicated in asthma exacerbations 2
Prescribing antibiotics unless there is clear evidence of bacterial infection (e.g., pneumonia or sinusitis) 2, 5

Measure PEF 15-30 minutes after starting treatment and then according to response 2
Continue oxygen therapy to maintain SaO₂ >90% (>95% in pregnant women and patients with heart disease) 5
If condition improves, give nebulized β-agonist every four hours 2
If condition does not improve after 15-30 minutes, give nebulized β-agonists more frequently (up to every 15 minutes) 2
Consider adding ipratropium bromide to β-agonist therapy to increase bronchodilation in severe cases 5