Thus, it makes sense that short-term studies have found no difference in outcomes, and that studies demonstrating positive effects on LOS and respiratory scores do so only after 24 hours of ther­apy. Fluid shifts take time, and cilia can only do so much.

Chinese investigators have reported similar positive outcomes, including a reduction in LOS from 7.4 to 6 days with hypertonic saline plus salbutamol in hospitalized infants (Pediatr. Int. 2010;

52:199-202). Moreover, these findings were replicated in a second study, this time using nebulized 3% hypertonic saline without concomitant broncho­dilators (Clin. Microbiol. Infect. 2010 July 15 [doi:10.1111/j.1469-0691.2010.03304.x]).

We’ve never seen this level of consistently positive results in the data on bronchiolitis treatment in the past, and it’s exciting – particularly as we have so little in our therapeutic armamentarium. It’s also very interesting to have a theory of mechanism of action that meshes with the known pathology in bronchiolitis. After years of repeatedly studying beta-agonists, even though we knew that airway smooth muscle reactivity was not the major pathology, it is refreshing to see a different approach emerging.

Dr. Ralston is chief of inpatient pediatrics at the University of Texas Health Science Center in San Antonio. She said she had no relevant financial disclosures.

It is too early to say if hypertonic saline is an appropriate therapy.

Much of the evidence supporting the use of nebulized hypertonic saline for acute bronchiolitis rests on changes in respiratory scores that are not likely to have clinical relevance. The true test is whether hypertonic saline can really reduce length of stay (LOS), the hard outcome that physicians and parents care about. That question remains unanswered.

No fewer than five short-term emergency department (ED) studies have failed to find a difference in outcomes between nebulized hypertonic saline and normal saline. One of those trials was by the same group of Canadian researchers that helped put nebulized hypertonic saline on the radar of many physicians (J. Pediatr. 2007;151:266-70).

When the Canadians studied hypertonic saline in the ED setting, there were no significant differences in hospital admission rates or respiratory scores after three consecutive 4-mL

doses of nebulized 3% hypertonic saline in children younger than age 2 years who presented to the ED with moderately severe bronchiolitis (CJEM 2010;12:477-84).

In addition, no large randomized trials from the United States have been conducted using our criteria for hospitalization. A recent Chinese study demonstrated a reduction in LOS with the use of hypertonic saline plus salbutamol in 93 infants hospitalized with mild to moderate bronchiolitis (Pediatr. Int. 2010;52:199-202). The reduction, however, was from 7.4 days to 6.0 days – an LOS that was more than double the U.S. average LOS of 2.5 days.