Bronchiolitis is a significant cause of morbidity and hospitalizations in children, accounting for more than 125,000 hospitalized children per year in the United States. Although treatment is largely supportive, bronchodilator medications such as albuterol are frequently used due to increased pulmonary resistance in this population.2-4 However, despite four decades of clinical trials, the efficacy of albuterol in the treatment of bronchiolitis has yet to be proven. This inconsistency is due in part to the lack of sufficiently sensitive methods for the evaluation of lung function and thus the response to albuterol in infants. Because of the difficulties in evaluating the response to therapy, healthcare providers are forced to rely on their physical examination skills or a clinical scoring system, both of which are highly subjective in this population. The investigators propose to conduct a prospective observational study of healthcare providers to determine the accuracy of clinical assessment as compared to that of pulmonary mechanics in a population of children intubated and mechanically ventilated for bronchiolitis.