Background: Systemic corticosteroid therapy is central to the management of acute asthma The use of ICS may also be beneficial in this setting.

Objectives: To determine the benefit of ICS for the treatment of patients with acute asthma managed in the emergency department (ED).

Search strategy: Randomised controlled trials (RCTs) were identified from the Cochrane Airways Review Group register. Bibliographies from included studies, known reviews, and texts also were searched.

Selection criteria: Only RCTs or quasi-randomised trials were eligible for inclusion. Studies were included if patients presented with acute asthma to the ED or its equivalent, and were treated with ICS or placebo, in addition to standard therapy. Two reviewers independently selected potentially relevant articles, and then independently selected articles for inclusion. Methodological quality was independently assessed by two reviewers.

Data collection and analysis: Data were extracted independently by two reviewers if the authors were unable to verify the validity of extracted information. Missing data were obtained from the authors or calculated from other data presented in the paper.

Main results: Seven trials were selected for inclusion, but data were not available for one of them. In the six usable trials, (4 adult, 2 paediatric), a total of 352 patients were studied (179 ICS, 173 non-ICS treated). Patients treated with ICS were less likely to be admitted to hospital (OR: 0.33; 95% CI: 0.17, 0.64). This benefit was confined to patients not receiving concomitant systemic steroids (CS). Patients receiving concomitant CS showed a similar, but non-significant, trend towards reduced admissions compared to placebo treatment (OR 0.45; 95% CI: 0.18, 1.14). Patients receiving ICS also demonstrated small, significant improvements in peak expiratory flows (PEFR WMD: 8%; 95% CI: 3, 13 %) and forced expiratory volumes (FEV1 WMD: 5%; 95% CI: 0.4, 10 %). The treatment was well tolerated, with few reported adverse side effects. A secondary analysis compared ICS alone vs CS alone; in the four trials included, there was significant heterogeneity between the study results for admission rates which precluded meaningful pooling of the study results.

Reviewer's conclusions: Inhaled steroids reduced admission rates in patients with acute asthma, but it is unclear if there is a benefit of ICS when used in addition to systemic corticosteroids. There is insufficient evidence that ICS therapy results in clinically important changes in pulmonary function or clinical scores when used in acute asthma. Similarly, there is insufficient evidence that ICS alone is as effective as CS. Further research is needed to clarify if there is a benefit of ICS when used in addition to CS.