Respiratory distress syndrome in the newborn: role of oxidative stress

Reactive oxygen and nitrogen species are generated by several inflammatory and structural cells of the airways. These oxidant species have important effects on a variety of lung cells as regulators of signal transduction, activators of key transcription factors and modulators of gene expression and apoptosis. Thus, increased oxidative stress accompanied by reduced endogenous antioxidant defenses may play a role in the pathogenesis of a number of inflammatory pulmonary diseases, including respiratory distress syndrome (RDS) in the newborn. There obviously are conflicting reports on the effect of oxygen, ventilation and nitric oxide (NO) on RDS and, thus, the question arises as what the neonatologist should do when confronted with a newborn with RDS. Clearly, utilizing lung protective strategies requires compromises between gas exchange goals and potential toxicities associated with over-distension, derecruitment of lung units and high oxygen concentrations. The results discussed in this brief review suggest rigorous clinical tests with antioxidants which may help to define the mechanisms associated with RDS and which could lead to new treatment strategies.