Lung ultrasound in premature infants as an early predictor of bronchopulmonary dysplasia.

Purpose: Lung ultrasound (LUS) is a widely used technique in neonates to diagnose a lot of acute diseases. However, its role in the diagnosis of chronic lung conditions is still to be evaluated. We aimed to describe the changes in ultrasound images as well as the appearance of lung consolidations (LC) in very low birth weight (VLBW) infants with and without bronchopulmonary dysplasia (BPD).

Methods: For a period of 2 years we prospectively examined 124 VLBW infants, divided into two main groups: below 28 gestational weeks with two subgroups-BPD (moderate and severe) and non-BPD, and 28-32 gestational weeks with two subgroups-BPD (moderate and severe) and non-BPD group. We performed weekly LUS until 36 weeks' postmenstrual age (PMA). On the seventh postnatal day, we calculated the LUS score as a semiquantitative score that represents the aeration (0-3) in three different areas (upper anterior, lower anterior, lateral) of each lung.

Results: We performed around 750 LUS exams. The BPD groups had LUS scores above 8 on the seventh day, p < 0.001. The number of LC was higher in the BPD groups 14 (3-45) than in the mild or non-BPD groups 2.5 (0-6), p < 0.001, and the difference was significant for the period between 1 week and 1 month after birth, p = 0.001. In the BPD group <28 weeks' PMA, LC appeared equally in the anterior, lateral, and posterior fields, while in the BPD group 28-32 weeks' PMA, LC are more typical for the anterior-lateral fields.

Conclusion: Serial LUS exams and identification of LC could be early predictors of moderate and severe forms of BPD. LUS score >8 on the seventh postnatal day is an early predictor of severe BPD. LC in more lung fields are typical for the severe forms of the disease.