Oxidant Stress, Hyperoxia/Hypoxia and Neonatal Respiratory Disorders

Area of Science:

• Neonatal Medicine
• Pediatric Pulmonology
• Biochemistry

Background:

• Preterm neonates possess limited antioxidant capacity, rendering them vulnerable to perinatal oxidant stress.
• Oxidant stress is implicated in major neonatal diseases, including respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), and pulmonary hypertension (PH).
• Hypoxia and hyperoxia exposure in preterm infants exacerbate oxidant stress and associated morbidities.

Purpose of the Study:

• To review the intricate relationship between oxidant stress, oxygen variations (hypoxia/hyperoxia), and respiratory ailments in neonates.
• To synthesize current understanding of how oxidative stress impacts the development and progression of neonatal respiratory disorders.

Main Methods:

• This narrative review synthesizes findings from preclinical and clinical studies.
• Literature search focused on oxidant stress biomarkers, antioxidant enzyme activity, and oxygen exposure effects in preterm infants with respiratory issues.

Main Results:

• Preterm infants with RDS and BPD exhibit elevated oxidative stress markers and diminished antioxidant enzyme activity.
• Intermittent hypoxemia is linked to BPD development, while hyperoxia exposure correlates with prolonged respiratory support and increased BPD rates.
• Preclinical evidence suggests hypoxia and hyperoxia contribute to PH, with hyperoxia potentially impairing pulmonary vasodilator efficacy.

Conclusions:

• Current antioxidant therapies lack routine clinical implementation due to modest efficacy and safety concerns.
• Optimizing oxygen administration, potentially using automated closed-loop systems, offers a promising strategy to mitigate neonatal oxidant stress.