Respiratory severity score-guided postnatal systemic corticosteroid therapy for bronchopulmonary dysplasia in extremely preterm infants.

Bronchopulmonary dysplasia (BPD) is a major complication in extremely preterm (EP) infants. Postnatal systemic corticosteroids reduce inflammation and may help prevent or treat BPD. However, their use is limited because of concerns regarding neurodevelopmental outcomes. However, the optimal timing and criteria for steroid therapy initiation remain unclear. This study aimed to evaluate the effect of a respiratory severity score (RSS)-guided postnatal systemic corticosteroid protocol on BPD and neurodevelopmental outcomes in mechanically ventilated infants with EP. A historical comparative study was conducted to compare the preprotocol (2010-2014; phase I) and postprotocol (2016-2022; phase II) periods. Infants born at <28 weeks' gestation and ventilated on postnatal day 14 were included in the study. The protocol implemented in 2015 used the RSS to guide corticosteroid initiation. Clinical outcomes including BPD severity and severe neurodevelopmental impairment (NDI) were compared. Among the 208 infants, those in phase II had higher dexamethasone use (17.6% vs. 33.0%, P=0.017) and earlier initiation (postmenstrual age, 31.1 vs. 29.0 weeks; P=0.027). In phase II, Jensen grade 0 was significantly increased (15.2% vs. 30.2%; adjusted odds ratio aOR, 2.31; P=0.024), particularly among patients who did not receive steroids. In steroid-treated infants, Jensen grade 3 BPD was decreased (47.4% vs. 21.2%; aOR, 0.26; P=0.050), whereas grade 1 BPD was increased (5.3% vs. 33.3%; aOR, 12.22; P=0.035) in phase II. There were no significant intergroup differences in mortality or NDI. The RSS-guided protocol enabled more targeted and earlier steroid administration, reducing severe BPD without worsening neurodevelopmental outcomes. This approach may refine postnatal corticosteroid treatment strategies for infants with EP.