BACKGROUND:We recently published preliminary evidence on the effectiveness of hypertonic saline in infants with viral bronchiolitis. OBJECTIVE:To further establish the efficacy of nebulized hypertonic saline in these infants. METHODS:In a continuing, second-year randomized, doubleblind controlled trial, an additional 41 infants (age 2.6 +/- 1 months) hospitalized with viral bronchiolitis were recruited during the winter of 2001-2002. The infants received inhalation of 1.5 mg epinephrine dissolved either in 4 ml normal (0.9%) saline (Group I, n=20) or 4 ml hypertonic (3%) saline (Group II, n=22). The therapy was repeated three times daily until discharge. Pooling our 2 years of experience (2000-2002), a total of 93 hospitalized infants with viral bronchiolitis were recruited; 45 were assigned to Group I and 48 to Group II. RESULTS:The clinical scores at baseline were 7.6 +/- 0.7 for Group I vs. 7.4 +/- 1.3 for Group II (P = NS). However, the clinical scores at days 1 and 2 after inhalation differed significantly between the two groups, invariably favoring Group II: 7 +/- 1 vs. 6.25 +/- 1.1 (P< 0.05), 6.45 +/- 1 vs. 5.35 +/- 1.35 (P< 0.05), respectively. Adding aerosolized 3% saline to 1.5 mg epinephrine reduced the hospitalization stay from 3.5 +/- 1.7 days in Group I to 2.6 +/- 1.4 in Group II (P< 0.05). The pooled data of both years revealed that adding 3% saline to the inhalation mixture decreased hospitalization stay from 3.6 +/- 1.6 to 2.8 +/- 1.3 days (P< 0.05). CONCLUSIONS:This second-year experience and our 2 year pooled data analysis strengthen the evidence that the combination of 3% saline/1.5 mg epinephrine benefits hospitalized infants with viral bronchiolitis.