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.