This week, we are highlighting a Cochrane summary on the effect of antibiotics on clinical outcomes in children with bronchiolitis.
We reviewed the evidence on the effect of antibiotics on clinical outcomes in children with bronchiolitis.
Bronchiolitis is a serious respiratory illness that affects babies. It is most commonly caused by respiratory syncytial virus (RSV) and is the most common reason for hospitalisation in babies younger than six months. Babies usually present with runny nose, cough, shortness of breath and signs of difficulty in breathing, which can become life-threatening. Despite its viral cause, antibiotics are often prescribed. Prescribers may be expecting benefits from anti-inflammatory effects attributed to some antibiotics or be concerned about secondary bacterial infection, particularly in children who are very unwell and require intensive care. We wanted to discover if antibiotics improved or worsened clinical outcomes in children with bronchiolitis.
This evidence is current to June 2014. We identified seven trials (824 participants) comparing antibiotics with placebo or no antibiotics in children with bronchiolitis. Two of these studies also compared intravenous and oral antibiotics.
Our primary outcome was duration of symptoms/signs (duration of supplementary oxygen requirement, oxygen saturation, wheeze, crepitations (crackles), fever). Secondary outcomes included duration of admissions/time to discharge from hospital, readmissions, complications/adverse events (including death) and radiological (X-ray) findings.
We included seven studies with a total of 824 participants. Four studies reported on duration of supplementary oxygen requirement and did not demonstrate a significant difference in the duration of oxygen use comparing antibiotics to placebo. We combined three studies comparing azithromycin versus placebo and again did not demonstrate a significant difference between antibiotics and placebo in the duration of oxygen requirement. Most of the included studies did not report on the primary outcomes of wheeze, crepitations and fever. One study with a high risk of bias found mixed results for the effects of antibiotics on wheeze but no difference for other symptom measures. One study found no difference in duration of fever and one study found no difference in presence of fever on day two.
In regards to secondary outcomes, six included studies did not find any difference between antibiotics and placebo for the outcomes of length of illness or length of hospital stay. For length of hospital stay, we combined data from three studies comparing the use of azithromycin versus placebo as a subtotal as part of the overall analysis of the effect of antibiotics on hospital stay. These combined results similarly showed no difference between antibiotics (azithromycin) and placebo. One small study with a high risk of bias found that three weeks of clarithromycin significantly reduced hospital readmission compared to placebo. However, this reduction in hospital readmissions was not replicated in a more recent study that randomised 97 children to receive either a single large dose of azithromycin or placebo. There were no deaths reported in any arms of any of the seven included trials and none of the studies specifically reported on adverse effects of antibiotics. Only two studies made general comments that no adverse effects were found with antibiotic use. Radiological findings were not reported as an outcome in any of the included studies.
Quality of the evidence
This 2014 updated review is stronger, owing to the inclusion of two new randomised controlled trials (RCTs). These two studies combined involved a further 138 participants in the antibiotic arm and 143 participants in the placebo arm. Prior to this only three small RCTs had examined antibiotics versus placebo, with only 72 participants in the antibiotic arms and 72 participants in the placebo arms. Consequently, this review makes a substantial contribution, especially with regards to the role of macrolides, such as azithromycin, in bronchiolitis. No new unpublished data have been included. However, the review authors have no reason to suspect that the search strategy has biased the review results. Raw data could not be obtained from one study conducted 40 years ago, nor from three other trials, which is a weakness of this review. Three trial authors did provide raw data for this review.
This review did not find sufficient evidence to support the use of antibiotics for bronchiolitis. Research may be justified to identify a subgroup of patients who may benefit from antibiotics.
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.
Check out the full Cochrane systematic review below:
Farley, R., Spurling, G. K., Eriksson, L., & Del Mar, C. B. (2014). Antibiotics for bronchiolitis in children under two years of age. Cochrane Database Syst Rev, 10, Cd005189. doi: 10.1002/14651858.CD005189.pub4
Related TREKK Resources:
This post is part of a weekly blog series highlighting pediatric emergency medicine (PEM) focused Cochrane summaries and other key resources selected by TREKK.
Published by arrangement with John Wiley & Sons.