Lung function response to postnatal corticosteroids for the prevention and treatment of bronchopulmonary dysplasia

Steroid treatment is well-known for producing clinically significant improvements in respiratory support requirements. In this study, we utilized lung ultrasound and respiratory oscillometry to objectively assess this response and determine if the combination of these methods can serve as a valuable tool for comparing different treatment strategies.

We conducted a retrospective observational study including preterm infants with a gestational age below 32 weeks and/or a birth weight below 1500 g. We measured lung ultrasound score (LUS) and respiratory system reactance (Xrs) by respiratory oscillometry before and after treatment with either systemic dexamethasone or inhaled budesonide.

We analyzed 46 treatments (9 dexamethasone, 37 budesonide) administered to 40 infants (median (Q1, Q3) postnatal age = 30 (18, 49) days, postmenstrual age = 33.29 (30.14, 35.00) weeks). All treatments were associated with a notable reduction in respiratory support and a concurrent improvement in either Xrs, LUS, or both. On average, Xrs improved from 3.13 (1.09, 5.41) to 0.44 (-0.90, 1.59) z-score (p < 0.001) and LUS from 10 (7, 12) to 5 (3, 8) (p < 0.001).

Xrs and LUS proved sensitive to lung function changes associated with corticosteroids; combining the two better described the response and its variability.

We found that respiratory system reactance (Xrs) and lung ultrasound score (LUS) are sensitive biomarker for monitoring changes in lung function associated with corticosteroids; Combining Xrs and LUS enhances evaluation compared to each method alone; These results have valuable implications in clinical practice, particularly in personalizing and monitoring corticosteroid treatment; The present paper suggests that the combined use of respiratory oscillometry and lung ultrasound holds value as a research tool in future studies investigating various treatment regimens, molecules, or administration routes.