Antibiotics for bronchiolitis in children under two years of age

Background Bronchiolitis is a serious, potentially life-threatening respiratory illness commonly affecting babies. It is often caused by respiratory syncytial virus (RSV). Antibiotics are not recommended for bronchiolitis unless there is concern about complications such as secondary bacterial pneumonia or respiratory failure. Nevertheless, they are often used. Objectives To evaluate the effectiveness of antibiotics for bronchiolitis in children under two years of age compared to placebo or other interventions. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2014, Issue 6), which includes the Cochrane Acute Respiratory Infection Group's Specialised Register, and the Database of Abstracts of Reviews of Effects, MEDLINE (1966 to June 2014), EMBASE (1990 to June 2014) and Current Contents (2001 to June 2014). Selection criteria Randomised controlled trials (RCTs) comparing antibiotics to placebo in children under two years diagnosed with bronchiolitis, using clinical criteria (including respiratory distress preceded by coryzal symptoms with or without fever). Primary clinical outcomes included time to resolution of signs or symptoms (pulmonary markers included respiratory distress, wheeze, crepitations, oxygen saturation and fever). Secondary outcomes included hospital admissions, length of hospital stay, readmissions, complications or adverse events and radiological findings. Data collection and analysis Two review authors independently analysed the search results. Main results We included seven studies with a total of 824 participants. The results of these seven included studies were often heterogeneous, which generally precluded meta-analysis, except for deaths, length of supplemental oxygen use and length of hospital admission. In this update, we included two new studies (281 participants), both comparing azithromycin with placebo. They found no significant difference for length of hospital stay, duration of oxygen requirement and readmission. These results were similar to an older study (52 participants) that demonstrated no significant difference comparing ampicillin and placebo for length of illness. One small study (21 participants) with higher risk of bias randomised children with proven RSV infection to clarithromycin or placebo and found a trend towards a reduction in hospital readmission with clarithromycin. The three studies providing adequate data for days of supplementary oxygen showed no difference between antibiotics and placebo (pooled mean difference (MD) (days) -0.20; 95% confidence interval (CI) -0.72 to 0.33). The three studies providing adequate data for length of hospital stay, similarly showed no difference between antibiotics (azithromycin) and placebo (pooled MD (days) -0.58; 95% CI -1.18 to 0.02). Two studies randomised children to intravenous ampicillin, oral erythromycin and control and found no difference for most symptom measures. There were no deaths reported in any of the arms of the seven included studies. No other adverse effects were reported. Authors' conclusions This review did not find sufficient evidence to support the use of antibiotics for bronchiolitis, although research may be justified to identify a subgroup of patients who may benefit from antibiotics. Further research may be better focused on determining the reasons that clinicians use antibiotics so readily for bronchiolitis, how to reduce their use and how to reduce clinician anxiety about not using antibiotics.