Secondary outcomes were total number of hours on mechanical ventilation, CPAP and supplemental oxygen during the first 7 days of life and for the entire hospitalization. Other secondary outcomes were number of surfactant doses, incidence of pulmonary air leak, survival until discharge, chronic lung disease (defined as need for oxygen at 36 weeks PMA), oxygen requirement at discharge, severe intraventricular hemorrhage (Grade 3/4), and periventricular leukomalacia.