Factors Associated with Clinical Response to Low-Dose Dexamethasone Therapy for Bronchopulmonary Dysplasia in Very Low Birth Weight Infants

Purpose: To identify factors associated with the clinical response to low-dose dexamethasone therapy (LDDT) in preterm infants for bronchopulmonary dysplasia (BPD). Methods: We used a retrospective medical record review to evaluate preterm infants who were born before 32 weeks of gestation or with a birth weight less than 1,500 g. All infants were admitted to the neonatal intensive care unit at a tertiary academic hospital between January 2010 and June 2019, and received LDDT for BPD. The preterm infants' respiratory severity scores (RSS) were calculated from the first day of LDDT to the day of extubation, or the last day of LDDT. A good response was defined as a decreasing RSS with a slope greater than 0.181. A poor response was defined as a non-decreasing RSS, or a decreasing RSS with a slope less than 0.181 during LDDT. A total dose of 1.1 mg/kg was administered for 10 days for each single course of LDDT. Results: A total of 51 preterm infants were included in the final analysis. Thirty preterm infants (58.8 %) were in the good response group, and 21 preterm infants (41.2%) were in the poor response group. There were no significant differences in gestational age, birth weight, and sex between the good response group and poor response group. Preterm premature rupture of membrane and histologic chorioamnionitis were significantly associated with a poor response to LDDT. Higher RSS on the first day of the LDDT was associated with a good response to LDDT. Conclusion: Antenatal infection and/or inflammation may be associated with an unfavorable response to postnatal LDDT for BPD. Preterm infants with more severe respiratory failure seem to benefit more from LDDT for BPD.