RESUMO
AIM: Despite advances in perinatal management, there is a flat trend in incidences of respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD) in preterm infants. The main feature of BPD development in preterm infants is an imbalance between increased exposure to free radicals and inadequate antioxidant defences. We investigated the associations between BPD and lipid hydro-peroxide (LOOH) and glutathione (GSH) concentrations in bronchoalveolar lavage fluid (BALF). METHODS: In this prospective study, BALF samples were collected from 44 preterm infants with RDS and oxidative stress markers were measured in 11 with BPD and 33 controls without BPD. RESULTS: LOOH levels were significantly higher (p < 0.01) in the BPD group (median 16.35; 25th-75th centile 13.75-17.05 nmol/mL) than in the no BPD group (median 13.18; 25th-75th centile 12.92-13.63 nmol/mL). Conversely, GSH levels were significantly lower in the BPD group (p < 0.01) (median 11.52; 25th-75th centile 6.95-13.85 µmol/mg) than the no BPD group (median: 18.69; 25th-75th centile: 13.89-23.64 µmol/mg). Multiple regression analysis showed significant correlations between BPD and mechanical ventilation time (p < 0.01) and LOOH levels (p < 0.05). CONCLUSION: Early LOOH level increases in preterm infants developing BPD suggest that lung biochemical monitoring of sick infants might be possible and BPD could be predicted early by evaluating biomarkers.