Lung ultrasound score as early predictor of bronchopulmonary dysplasia in very low birth weight infants

BACKGROUND: Lung ultrasound (LU) has been widely used to diagnose and monitor acute lung diseases in neonates, but its role in chronic diseases has not been elucidated. OBJECTIVE: We aim to describe the evolution of a lung ultrasound score (LU score) in very low birth weight infants (VLBWI) with and without bronchopulmonary dysplasia (BPD). METHODS: We prospectively included 59 VLBWI and performed LU in the first 24 and 72 hours of life, and then weekly until 36 weeks´ postmenstrual age (PMA). We calculated the LU score as a semiquantitative score representing the aeration (0-3) in three different areas of each lung. RESULTS: The non-BPD group (n = 38) had lower LU score at 1, 2, 3, 4, and 36 weeks' PMA than the BPD group: median score of 1 (0-4) vs 7 (3-10), P < .001; 0 (0-1) vs 7 (4-9), P < .001; 0 (0-1) vs 8 (7-11), P < .001; 0 (0-2) vs 9 (4-12), P < .001; 0 (0-0) vs 3 (0-6), P < .001. A LU score of 5 or above at 1 week of life predicted BPD with a sensitivity (Se) of 71%, specificity (Sp) 80%, area under the ROC curve (AUC) 0.8, and at 2 weeks of life with Se 74%, Sp 100%, and AUC 0.93. An LU score of 4 or above at 4 weeks predicted moderate-severe BPD (Se 100%, Sp 80%, and AUC 0.89). CONCLUSION: In VLBWI without BPD, LU score increases during the first week of life and decreases thereafter, whereas among subjects with BPD, the LU score remains high until 36 weeks´ PMA. LU score can predict the diagnosis of BPD at 1 week and 2 weeks of life, and may predict moderate-severe BPD at 4 weeks of life.