 This study demonstrated that certain pulmonary function test parameters may be associated with bronchodilator response in infants with broncopulmonary dysplasia. Specifically, infants who responded to bronchodilators had lower forced expiry volume in 0.5 seconds, FeV 0.5, as well as a lower disenapsi ratio, compared to those who did not respond. Additionally, these infants had evidence of greater disenatic lung growth than those who did not respond. These results suggest that pulmonary function tests may be useful in identifying infants at risk for poor bronchodilator response. This article was authored by Leif Dean-Ellen, Matthew J. Kield, Maria Jebbia, and others.