Corticosteroids for preventing relapse following acute exacerbations of asthma.

BACKGROUND: Acute asthma is responsible for many emergency department (ED) visits annually. Between 12 to 16% will relapse to require additional interventions within two weeks of ED discharge. Treatment of acute asthma is based on rapid reversal of bronchospasm and reducing airway inflammation.
OBJECTIVES: To determine the benefit of corticosteroids (oral, intramuscular, or intravenous) for the treatment of asthmatic patients discharged from an acute care setting (i.e. usually the emergency department) after assessment and treatment of an acute asthmatic exacerbation. SEARCH STRATEGY: We searched the Cochrane Airways Group Specialised Register and reference lists of articles. In addition, authors of all included studies were contacted to locate unpublished studies. The most recent search was run in October 2006. SELECTION CRITERIA: Randomized controlled trials comparing two types of corticosteroids (oral, intra-muscular, or inhaled) with placebo for outpatient treatment of asthmatic exacerbations in adults or children. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted data. Study authors were contacted for additional information. MAIN
RESULTS: Six trials involving 374 people were included. One study used intramuscular corticosteroids, five studies used oral corticosteroids. The review was split into two reviews and although the latest search yielded no additional placebo controlled trials an additional IM study was included. Significantly fewer patients in the corticosteroid group relapsed to receive additional care in the first week (Relative risk (RR) 0.38; 95% confidence interval (CI) 0.2 to 0.74). This favourable effect was maintained over the first 21 days (RR 0.47; 95% CI 0.25 to 0.89) and there were fewer subsequent hospitalizations (RR 0.35; 95% CI 0.13 to 0.95). Patients receiving corticosteroids had less need for beta(2)-agonists (mean difference (MD) -3.3 activations/day; 95% CI -5.6 to -1.0). Changes in pulmonary function tests (SMD 0.045; 95% CI -0.47 to 0.56) and side effects (SMD 0.03; 95% CI -0.38 to 0.44) in the first 7 to 10 days, while rarely reported, showed no significant differences between the treatment groups. Statistically significant heterogeneity was identified for the side effect results; all other outcomes were homogeneous. From these results, as few as ten patients need to be treated to prevent relapse to additional care after an exacerbation of asthma. AUTHORS'
CONCLUSIONS: A short course of corticosteroids following assessment for an asthma exacerbation significantly reduces the number of relapses to additional care, hospitalizations and use of short-acting beta(2)-agonist without an apparent increase in side effects. Intramuscular and oral corticosteroids are both effective.