Parts I, II, and III are still there for those of you yet to dive in but now we turn our attention to a lesser used, but potentially valuable therapy in bronchiolitis. ED providers are already familiar with its use in the management of elevated intracranial pressure. What is it? Nebulized hypertonic (3%) saline of course.

It is thought to increase mucociliary clearance by affecting both the the character of the mucous (essentially rehydrating it through osmotic and ionic effects) and its clearance (by stimulating cilia through prostaglandin release, reducing airway wall edema, and increasing cough). You’d be right to assume that these effects are not limited to bronchiolitis. They are known to occur in asthmatics, cystic fibrosis, and healthy patients alike.

Sounds great – does it work? Well, let’s take a look at a recent Cochrane Review from Zhang et al. The authors searched for RCTs of which there were only four, and noted the following;

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  • Patients treated with nebulized 3% saline had a significantly shorter mean inpatient LOS compared to those treated with nebulized 0.9% saline (mean difference (MD) -0.94 days, 95% CI -1.48 to -0.40, P = 0.0006)
  • The 3% saline group also had a significantly lower post-inhalation clinical score than the 0.9% saline group in the first three days of treatment (day 1: MD -0.75, 95% CI -1.38 to -0.12, P = 0.02; day 2: MD -1.18, 95% CI -1.97 to -0.39, P = 0.003; day 3: MD -1.28, 95% CI -2.57 to 0.00, P = 0.05)
  • The effect of nebulized hypertonic saline in improving clinical score was greater among outpatients than inpatients
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This all sounds great, but clearly the evidence isn’t earth shattering. Besides many of us don’t routinely give 9% saline nebs alone. There are some investigators looking into albuterol + hypertonic saline in other populations. Ater et al found that combining albuterol with 5% saline in wheezing preschoolers reduced the rate of admission and improved clinical scores. 

Do I use hypertonic saline nebs in my routine practice of bronchiolitis? Not at this time. Though upcoming studies will undoubtedly shed light on the subject I am hesitant to employ it regularly until more evidence is available.

Look for more coming soon in the bronchiolitis series – specifically focusing on non-MLB steroids. And again, thanks to Todd Florin, MD, MSCE.