Resuscitation of Preterm Infants with Reduced Oxygen Results in Less Oxidative Stress than Resuscitation with 100% Oxygen

The objective of this study was to determine the effects of the level of inhaled oxygen during resuscitation on the levels of free radicals and anti-oxidative capacity in the heparinized venous blood of preterm infants. Forty four preterm infants <35 weeks of gestation with mild to moderate neonatal asphyxia were randomized into two groups. The first group of infants were resuscitated with 100% oxygen (100% O2 group), while in the other group (reduced O2 group), the oxygen concentration was titrated according to pulse oximeter readings. We measured total hydroperoxide (TH) and redox potential (RP) in the plasma within 60 min of birth. The integrated excessive oxygen (∑(FiO2-0.21) × Time(min)) was higher in the 100% O2 group than in the reduced O2 group (p<0.0001). TH was higher in the 100% O2 group than in the reduced O2 group (p<0.0001). RP was not different between the 100% O2 and reduced O2 groups (p = 0.399). RP/TH ratio was lower in the 100% O2 group than in the reduced O2 group (p<0.01). We conclude that in the resuscitation of preterm infants with mild to moderate asphyxia, oxidative stress can be reduced by lowering the inspired oxygen concentration using a pulse oximeter.