Claims that nebulized hypertonic saline reduces the length of hospital stay in children with acute bronchiolitis has been questioned by an Australian respiratory physician.

Writing in BMC Pulmonary Medicine Dr Mark Everard, a paediatric respiratory physician at the University of Western Australia, and colleagues noted that a Cochrane review published in 2013 had concluded: “nebulized 3% saline may significantly reduce length of hospital stay and improve the clinical severity score in infants with acute viral bronchiolitis”.

But according to the research team the conclusion was hard to justify on two counts; high levels of heterogeneity hampered the findings and the Cochrane group had overlooked a number of trials.

Conducting a review of the latest evidence the researchers identified 15 trials published up until 2015.

However they discovered disparities between the results of the largest trials and high levels of heterogeneity.

They said the findings showed that neither individual trials nor pooled estimates provided a firm evidence base for the use of hypertonic saline in inpatient acute bronchiolitis.

“The findings appear at best highly dependent on trial design and local policies…we cannot rule out the possibility that inhaled hypertonic saline offers symptomatic relief but have no data to support or deny this possibility,” they said.

The refutation of initially large treatment effects in small trials by larger trials is a phenomenon that should not be surprising, the research team said.

For instance in the treatment of acute bronchiolitis initial evidence supporting the use of beta-2 agonists was overturned as successive trials were published.