Lung Ultrasound in Bronchopulmonary Dysplasia: Patterns and Predictors in Very Preterm Infants

Introduction: Lung ultrasound (LUS) is useful for respiratory management in very preterm infants (VPI), but little is known about the echographic patterns in bronchopulmonary dysplasia (BPD), the relation between the image findings, and the severity of the disease and its long-term outcomes. We aimed to describe LUS patterns in BPD and analyze the accuracy of LUS to predict the need for respiratory support at 36 weeks postmenstrual age (PMA) in VPI. Methods: Preterm infants ≤30.6 weeks of gestational age were recruited. LUS was performed at admission, at 7th, and 28th day of life (DOL) with a standardized protocol (6 zones: anterior, lateral, and posterior fields). Clinical data, respiratory outcomes, and image findings were recorded. Results: Eighty-nine patients were studied. Infants with BPD had significantly higher LUS score at admission, at 7th, and 28th DOL. Patients with BPD exhibited more consolidations and pleural line abnormalities at 7th and 28th DOL than those without BPD (p < 0.001), regardless of the definition used for BPD. LUS at 7th DOL predicted NICHD 2001-BPD with R 2 = 0.522; AUC = 0.87 (0.79–0.94), p < 0.001, and Jensen 2019-BPD with R 2 = 0.315 (AUC = 0.80 [0.70–0.90], p < 0.001). A model including mechanical ventilation >5 days, oxygen therapy for 7 days and LUS score at 7th DOL accurately predicted the need for respiratory support at 36 weeks PMA (R 2 = 0.655, p < 0.001) with an AUC = 0.90 (0.84–0.97), p < 0.001. Conclusion: LUS score, pleural line abnormalities, and consolidations can be useful to diagnose BPD in VPI and to predict its severity after the first week of life.