Relationship between clinical severity of "new" bronchopulmonary dysplasia and HRCT abnormalities in VLBW infants.

Background: To assess the relationship between HRCT abnormalities and the clinical severity of "new" bronchopulmonary dysplasia (BPD) and respiratory assistance in <1500 g preterm infants.

Methods: HRCT was performed at the time of discharge in 109 preterm infants with BPD who were born between 2008 and 2014. BPD severity was defined as mild, moderate, or severe according to the NIH diagnostic criteria. Total HRCT scores for each infant were obtained from the sum of the number of BPD lobes assessed by two radiologists: a hyperaeration score (Hs) composed of decreased attenuation, mosaic attenuation, and bulla/bleb, and a parenchyma score (Ps) composed of linear lesions, consolidation, bronchial wall thickening, and bronchiectasis. We compared HRCT scores based on BPD severity and respiratory modes, such as invasive mechanical ventilation (IMV), non-invasive MV (NIMV), and oxygen therapy.

Results: Among the group of included infants (n = 101), mild BPD was found in 46.5%, moderate BPD in 45.5%, and severe BPD in 7.9%. When partial correlation was adjusted by gestational age (GA) and birth weight, the duration of NIMV was correlated with Ps (r = 0.382, P < 0.001), Hs (r = 0.223, P = 0.027), and total score (r = 0.384, P < 0.001). The duration of oxygen therapy was correlated with Ps (r = 0.374, P < 0.001) and Hs (r = 0.227, P = 0.023). Ps showed a correlation with BPD severity (r = 0.381, P = 0.007) in infants born at ≤26 weeks (GA) and those born at >27 weeks GA (r = 0.298, P = 0.042).

Conclusions: Parenchymal changes showed a greater correlation with the clinical severity of "new" BPD cases, especially in infants born at ≤26 weeks GA. The use of NIMV showed a greater correlation with Ps than Hs.