There’s probably no common illness with quite so much flailing about in the evidence base than bronchiolitis. Between bronchodilators, steroids, saline, and epinephrine, they’ve thrown the kitchen sink at it. Some show potential benefit, while others do not.
This is another study following up the suspected benefit of nebulized hypertonic (3%) saline in reducing length of stay in hospitalized patients. In a randomized trial, these authors enrolled 227 patients to receive either nebulized 3% saline or 0.9% saline placebo. There were no important differences between patients randomized to each arm. By all outcome measures – intensive care unit admission, objective deterioration of respiratory status, inpatient length-of-stay, or readmission – there was no difference between therapies.
The effect seen here – with seemingly contradictory results – is probably precisely as predicted by Ioannidis’ statistical theory regarding “Why Most Published Research Findings are False”. Simply put, the prior probability of any of these treatments being helpful is quite low – and the extent of random bias associated most of these studies high. The net effect, then, is the posterior probability associated with any significant finding is barely changed.
Nebulized hypertonic saline is probably harmless, but if it’s not helpful, it still doesn’t have a role.
“3% Hypertonic Saline Versus Normal Saline in Inpatient Bronchiolitis: A Randomized Controlled Trial”
http://pediatrics.aappublications.org/content/early/2015/11/04/peds.2015-1037
50 years ago, this was published: http://www.ncbi.nlm.nih.gov/pubmed/14261972 Despite 5 decades of flogging the topic, we're pretty much back where they started.