Background: Previous systematic reviews have not shown clear benefit of glucocorticoids for acute viral bronchiolitis, but their use remains considerable. Recent large trials add substantially to current evidence and suggest novel glucocorticoid-including treatment approaches.
Objectives: To review the efficacy and safety of systemic and inhaled glucocorticoids in children with acute viral bronchiolitis.
Search strategy: We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, issue 4); MEDLINE (1950 to November 2009); EMBASE (1980 to Week 47 2009); LILACS (1982 to November 2009); Scopus® (1823 to November 2009); and IRAN MedEx (1998 to November 2009).
Selection criteria: Randomised controlled trials (RCTs) comparing short-term systemic or inhaled glucocorticoids versus placebo or another intervention in children < 24 months with acute bronchiolitis (first episode with wheezing). Our primary outcomes were: admissions by days 1 and 7 for outpatient studies; and length of stay (LOS) for inpatient studies. Secondary outcomes included clinical severity parameters, healthcare use, pulmonary function, symptoms, quality of life and harms.
Data collection and analysis: Two authors independently extracted data on study and participant characteristics, interventions and outcomes. We assessed risk of bias and graded strength of evidence. Inpatient and outpatient results were meta-analysed separately using random-effects models. We pre-specified subgroup analyses, including the combined use of protocolised bronchodilators.
Main results: We included 17 trials (2596 participants); only two had low overall risk of bias. Baseline severity, glucocorticoid schemes, comparators and outcomes were heterogeneous. Glucocorticoids did not significantly reduce outpatient admissions by days 1 and 7 when compared to placebo (pooled risk ratios (RRs) 0.92; 95% CI 0.78 to 1.08; and 0.86; 95% CI 0.7 to 1.06, respectively). There was no benefit in LOS for inpatients (mean difference -0.18 days; 95% CI -0.39 to 0.04). Unadjusted results from a large factorial low risk of bias RCT found combined high-dose systemic dexamethasone and inhaled epinephrine reduced admissions by day 7 (baseline risk of admission 26%; RR 0.65, 95% CI 0.44 to 0.95; number needed to treat 11, 95% CI 7 to 76), with no differences in short-term adverse effects. No other comparisons showed relevant differences in primary outcomes.
Authors' conclusions: Current evidence does not support a clinically relevant effect of systemic or inhaled glucocorticoids on admissions or length of hospitalization. Combined dexamethasone and epinephrine may reduce outpatient admissions, but results are exploratory and safety data limited. Future research should further assess the efficacy, harms and applicability of combined therapy.