Additive effects of dexamethasone in nebulized salbutamol or L-epinephrine treated infants with acute bronchiolitis

Background: Although it is the most common lower respiratory infection of infancy, the optimal treatment for acute bronchiolitis is still controversial. The aim of this study was to compare the early and late effects of nebulized L-epinephrine (EPI) and intramuscular dexamethasone (DEX) combination therapy with nebulized salbutamol (SAL) and dexamethasone combination and bronchodilators alone in outpatients with acute bronchiolitis. Methods: A total of 69 infants aged 2-21 months who were admitted to the Pediatrics Department of the Faculty of Medicine, Mersin University, with acute bronchiolitis were included in a randomized, placebo-controlled, prospective trial study. Patients were assigned to receive either nebulized L-epinephrine (3 mg) or salbutamol (0.15 mg/kg) and 15 min later, either dexamethasone 0.6 mg/kg or placebo (PLA), intramuscularly, in a double-blind randomized fashion. The study groups were: epinephrine + dexamethasone group (group 1, n = 23), salbutamol + dexamethasone group (group 2, n = 23), epinephrine + placebo group (group 3, n = 11), and salbutamol + placebo group (group 4, n = 12). The outcome measures were heart rate, respiratory rate and Respiratory Distress Assessment Instrument (RDAI) score determined at 30, 60, 90 and 120 min, 24 h, and 5 days after the first therapy. Patients were then followed-up during the subsequent 2 months for the prevalance of respiratory complaints regarding bronchial hyperreactivity. Results: There were no significant differences between the outcome variables of the four groups within the first 120 min and at 24 hours, or between the rates of requirement of a second dose of the same bronchodilator. However, fifth day RDAI score values of both DEX groups were significantly lower than that of SAL + PLA group (P = 0.000 and P = 0.01, respectively). The fifth day score value of group 1 was also significantly better than that value of EPI + PLA group but not different from group 2. Conclusions: A single dose of intramuscular dexamethasone added to nebulized L-epinephrine, or salbutamol therapies resulted in better outcome measures than bronchodilators alone in the late phase (fifth day) of mild to moderate degree bronchiolitis attack. However, effects of EPI + DEX combination was not different from SAL + DEX combination.