Inpatient Infants younger than 2 years of age with first episode of RSV bronchiolitis will be randomly assigned to treatment with nebulized epinephrine (1 mg diluted with 3 ml of 0.9% saline) or nebulized albuterol (2.5 mg diluted with 3.5 ml of 0.9% saline). Both solutions will be provided in identical containers.