Nebulized epinephrine does not improve clinical status or reduce the length of the hospital stay in infants aged <1 year with acute bronchiolitis. It also does not reduce clinical scores during or shortly after medication administration. In this study, infants requiring oxygen and intravenous fluids-presumably the sickest infants in the study-required longer hospital stays if they received epinephrine. A wheezing infant may be presenting with a first episode of asthma, so a trial of bronchodilators would seem reasonable; however, it appears that the primary intervention for bronchiolitis is supportive treatment, with supplemental oxygen, intravenous fluids, and ventilatory support when needed.