Background Development of lung function over time in relation to BPD severity, clinical symptoms, and neonatal risk factors have not been studied in detail.
Aim To compare outcomes of infant spirometry in preterm children with variable severity of BPD (levels 1–3) and correlate these to neonatal characteristics and airway symptoms during first 2 years of life.
Methods Neonatal data and clinical records from 53 preterm children (weeks 23–30) with BPD (mild, moderate, and severe) were compared with results of two follow-up infant spirometries (at 3 and 18 months corrected age). Respiratory function was assessed during sedation with tidal forced expirations for VmaxFRC according to standardised procedures.
Results Mean values of VmaxFRC z-score showed impaired lung function for all stages of BPD both at 3 and 18 months. Vmax FRC was significantly lower (p = 0,017) among children with moderate-severe BPD compared to mild BPD at the second follow-up. There was a significant correlation between VmaxFRC and birth weight (p = 0,004), but not to gestational age or to any specific neonatal complication. In the follow-up, 60% of the children experienced recurrent symptoms of airway obstruction, evaluated as regular use of inhaled corticosteroids or montelukast, and this incidence was significantly higher among the moderate and severe group (p = 0,007).
Conclusion Severity of BPD, in parallel to birth weight, correlates to impairment of lung function during first years of life and patient’s need for anti-inflammatory treatment of the airways. Lung function testing is a useful tool for identifying the BPD patients with special needs for follow-up.