Patient enrolled
Patients were diagnosed with sBPD if they met the following criterias7 described by National Institute of Child Health and Development (NICHD). An infants is diagnosed with sBPD if 1) born prior to 32 weeks postmenstrual age (PMA) and required supplemental oxygen for ≥28 days and ≥30% oxygen concentration or PPV at 36 weeks PMA, 2) born after 32 weeks gestational age and prior to 37 weeks gestational age who required supplemental oxygen for ≥28 days and ≥30% oxygen concentration or PPV at 56 days of life. As the use high flow nasal cannula (HFNC) was not specified, infants born prior to 32 weeks PMA or born after 32 weeks but prior to 37 weeks PMA were defined as having sBPD if on >2 LPM with any inspired oxygen at 36 weeks PMA or 56 days of life respectively. Failure of extubation was defined by a need for re-intubation within 48 hours of extubation. Infants with congenital cardiovascular disease were excluded from this study.