G449 Lung function at follow-up of very prematurely born young people – impact of bronchopulmonary dysplasia. (12th March 2018) - Morris, S
Abstract : Aims: Bronchopulmonary dysplasia (BPD) is a common adverse outcome of very premature birth. Studies have given conflicting results as to whether BPD is associated with long-term lung function impairment, but few have included populations exposed to routine use of antenatal steroids and postnatal surfactant. To determine, according to BPD status, the lung function of 16 to 18 year old, very prematurely born young people (<29 weeks of gestational age) of whom more than 90% were exposed to both antenatal steroids and postnatal surfactant. Methods: Lung function was assessed in 59 (34 of whom had BPD) young people. Airway function was assessed including by forced expiratory flow at 75% and 25% of the expired vital capacity (FEF75, FEF25–75 ), forced expiratory volume in one second (FEV1 ) and peak expiratory flow (PEF). Lung volumes were assessed including by total lung capacity (TLC), forced vital capacity (FVC), functional residual capacity by helium gas dilition(FRCHe ). Gas transfer was assessed by the diffusing capacity for carbon dioxide (DLCO) . The results were converted to z- scores, corrected for height, sex and ethnicity using GLI reference ranges. Results: The BPD and no BPD group were of similar height and weight at assessment. The lung function results are expressed as mean z score (standard deviation). Airway function (FEF75 −1.31 (1.35) versus −0.64 (0.89), p=0.035; FEF25–75 -1.88 (1.42) versus −1.10 (0.84), p=0.020; FEV1 −1.41 (1.44) versus −0.52 (1.23), p=0.017) and gas transfer DLCO (−1.50 (1.22) versus −0.72 (1.22), p=0.019) were significantly lower in those with BPD compared to those who had not developed BPD. Lung volumes (TLC 0.81 (1.24) versus 1.01 (0.82), p=0.504; FVC −0.54 (1.36) versus 0.13 (1.53), p=0.086 and FRC He 0.30 (1.11) versus −0.16 (1.20), p=0.669) were similar in the BPD and no BPD groups Conclusions: Airway function was significantly lower in the young people who had BPD, whereas lung volumes did not differ significantly between the two groups. Those results suggest that dysynaptic growth may be more pronounced in those who had BPD.