The effect of oxygen and parenteral nutrition on the redox potential and bronchopulmonary dysplasia in extremely
preterm infants
Introduction: oxygen supplementation and total parenteral solution (TPN) are two main clinical practices that sustain oxidative stress. Glutathione is a key molecule that detoxifies peroxides resulting in a more oxidized redox potential. We hypothesize that O2 supplementation and longer TPN duration are associated with both more oxidized redox potential and more severe bronchopulmonary dysplasia (BPD). Patients and methods: A prospective observational study including infants of less than 29 weeks gestational age. GSH and GSSG from whole blood sampled on day 6-7 and at 36 weeks of corrected age (CA) were measured by capillary electrophoresis and redox potential was calculated using Nernst equation. BPD was classified according to NICHD guidelines. Results: There was a significant association between FiO2 ≥ 25% on day 7 of life and TPN duration longer than 14 days and both more oxidized redox potential and more severe BPD. TPN duration explained both 15 % of total variation observed in redox potential and 42 % of total variation in BPD severity. These associations remained significant after adjustment for gestational age and illness severity. The relation between the severity of BPD and the redox potential in blood was not significant. The statistic power (1-β) to show an effect of redox potential on severity of BPD was 52%. Conclusion: Both redox potential of glutathione and BPD severity are both associated with early O2 supplement and TPN. Strategies targeting judicious use of O2 supplement and either decreasing the duration or using safer formulation of TPN are expected to help reducing BPD.
premature infants oxygen total parenteral nutrition oxidative stress bronchopulmonary dysplasia