Inhaled Hypertonic Saline Use in the Emergency Department to Treat Acute Viral Bronchiolitis

Acute viral bronchiolitis is a lower airway infection, caused manly by Respiratory Syncytial Virus. Near 1% of children up to 2 years of age get it with sufficient severity to warrant hospital admission, with an annual cost of about U$ 500 million in the US, superior, for instance, than cystic fibrosis annual cost.

Despite the physiopathology and clinical course being well known among pediatricians, few therapeutical options other than adequate hydration and oxygen supplementation have proven to be effective Corticosteroids are not effective and bronchodilators are controversial, and treatment is still mostly empiric and lacking evidence.

In the last few years, there has been a growing interest in the use of nebulized hypertonic saline (HS) as a promising approach. The rational is that HS would help reducing edema and mucus viscosity, enhancing its rheologic properties. Recent studies suggest that HS could reduce up to 1 day (25%) of time until discharge in admitted patients. In the Emergency Department, HS was not superior to other forms of treatment, but these studies lack power and similarities to draw further conclusions. Also, time of treatment and ideal interval between doses are not known as yet.

To our knowledge, few if any studies have assessed patients with an intermediary (up to 24h) time of stay, namely a short stay ward attached to an emergency department. Thus, we have endeavoured to determine if repeated doses of nebulized HS are superior to nebulized normal saline (NS) during the first 24 hour of treatment, when considered: rate of admission, time until discharge, time until attain discharge criteria, and rate of readmission after discharge.

Furthermore, most studies use HS associated to a bronchodilator, because of a theoretical possibility that HS alone could induce bronchoconstriction and worsen respiratory symptoms. However, recent studies have shown that HS use without bronchodilators have not caused any worsening of symptoms in bronchiolitis patients. Therefore, we propose to study the effect of HS alone, without the adding of bronchodilators, which would minimize bias in the treatment group.