Background: Acute asthma attacks occur when there is progressive airway narrowing caused by airway edema, inflammation, and increased bronchiolar smooth-muscle tone. The goals of treatment are to improve oxygen flow, reduce airway narrowing with rapid-acting inhaled bronchodilators, and decrease airway inflammation with early administration of systemic corticosteroids. The use of corticosteroids decreases the need to hospitalize patients with acute asthma attacks. Inhaled corticosteroids have been considered ineffective in treating acute exacerbations. Previous systematic reviews of inhaled corticosteroids in acute asthma attacks have shown inconsistent results. Rodrigo analyzed the best published data on the early effectiveness (one to four hours) of inhaled corticosteroids in the treatment of acute asthma in the emergency department.

The Study: The author searched multiple databases for randomized controlled trials that assessed the early effect of inhaled corticosteroids in the treatment of asthma in the emergency department. The author also searched references from the selected articles, the top 20 respiratory and emergency care journals, and unpublished data from primary authors of the articles.

The inclusion criteria were randomized trials that evaluated inhaled corticosteroids in the management of acute asthma in children six months to 17 years of age and adults 18 years and older. Trials had to compare inhaled corticosteroids with placebo or systemic corticosteroids, and must have evaluated the effectiveness of the intervention one to four hours after initiating therapy.

Main outcome measures were admission to the hospital and emergency department discharges. Secondary outcomes included spirometry measurements, clinical symptoms, heart and respiratory rates, oxygen saturation levels, and adverse effects.

Results: The author identified 17 studies that met the inclusion criteria, with a total of 470 adults and 663 children enrolled. The studies were divided into those that used multiple inhaled steroid dosing (i.e., three or more inhalations in 30 minutes or less) and those that used a single dose (i.e., two or fewer doses in 30 minutes or less, or one or more doses at greater than 30-minute intervals). When all trials that used multiple dosing of inhaled corticosteroids were pooled, there was a significant reduction in the hospital admission rate (odds ratio = 0.30; 95% confidence interval, 0.16 to 0.55). Discharge rates from emergency departments after two to three hours of treatment were greater in the inhaled corticosteroid group compared with placebo and systemic corticosteroids groups. Spirometry measurements were also significantly better in the inhaled corticosteroid group, particularly in those receiving multiple doses. None of the studies reported serious adverse effects with the use of inhaled corticosteroids.

Conclusion: The author concludes that inhaled corticosteroids appear to have a favorable effect on adults and children with acute asthma attacks if used early in the treatment plan. This is particularly true if multiple doses are given at intervals of 30 minutes or less over a total of 90 to 120 minutes.