Polysomnography findings in infants with severe bronchopulmonary dysplasia (BPD)

Abstract

Background: Bronchopulmonary dysplasia (BPD) is the most frequent serious complication in preterm infants, resulting in significant respiratory morbidity. Objectives: To compare overnight polysomnography (PSG) findings between preterm infants with severe BPD and term infants. Methods: Infants with severe BPD who underwent PSG at 6 months corrected age were included. Severe BPD was diagnosed in infants born < 32 weeks gestational age (GA) who required at least 28 days of oxygen, and needed ≥ 30% oxygen or positive end expiratory pressure at 36 weeks GA. Controls were term infants without BPD who underwent PSG for non-respiratory diseases,. All PSG signals were recorded and analyzed with BrainRT Shell+ (OSG BVBA, Rumst, Belgium) and scored according to international criteria. Mann-Whitney U test was used for between group comparisons. Results: 13 infants with severe BPD and 12 term infants without BPD (corrected age at PSG: 6.2 vs. 8.1 months) were included. Mean heart rate and breathing frequency did not differ between the groups, but mean SaO2 was lower in the BPD group compared to controls (96% [IQR 94.8;97,5] vs 98% [IQR 97;98],p=0.04). Severe BPD infants had higher apnea hypopnea index (AHI) (7.5 [4.5;10.6] vs 2.3 [0.9; 2.9],p < 0.01), higher oxygen desaturation index (ODI) (7.0 [3.9; 12.7] vs 3.1 [1.3; 3.9],p<0.01) and central apnea index (CAI) (2.4 [0.4;4.4] vs 0.4 [0;0.7],p<0.01) compared to controls, while sleep quality ( p =0.270) between the groups did not differ. Conclusion: Preterm infants with severe BPD had lower mean SaO2, and elevated AHI, ODI and CAI even at 6 months corrected age when compared to term infants. We speculate that this reflects a decreased pulmonary reserve due to BPD.