To explore regional cerebral oxygen saturations (rcSO₂) in preterm neonates initially stabilized with 0.3 fractionated inspired oxygen (FiO₂) concentrations. We hypothesized that those infants who received >0.3 FiO₂ during stabilization following delivery would have relatively higher rcSO₂ postdelivery compared with those stabilized with a lower FiO₂.

A single center prospective observational study of 47 infants born before 32 weeks. Using near infrared spectroscopy, rcSO₂ values were recorded immediately after birth. All preterm infants were initially given 0.3 FiO₂ and were divided into 2 groups according to subsequent FiO₂ requirements of either ≤0.3 or >0.3 FiO₂. Using a mixed-effects model, we compared the difference between the groups over time. Also, the area measures below 55% (hypoxia) and above 85% (hyperoxia) were compared between the groups.

The mean (SD) gestation was 29.4 (1.6) weeks and the mean (SD) weight was 1.3 (0.4) kg. Less than one-half of the infants (20/45; 43%) required ≤0.3 FiO₂. In the delivery suite, the median (IQR) rcSO₂ in the low and high FiO₂ groups were 81% (66%-86%) and 72% (62%-86%), respectively. Patients in the high FiO₂ group had a larger rcSO₂ area below 55% (P = .01). There was a significant difference in rcSO₂ between the groups (P < .05), with the low group having higher rcSO₂ values initially, but this difference changed over time. In the neonatal intensive care unit (NICU), rcSO₂ values were lower by 7.1% (CI 12.13 to 2.06%) P = .008 in the high FiO₂ group.

Infants given >0.3 FiO₂ had more cerebral hypoxia than infants requiring ≤0.3 FiO₂ but no difference in the degree of cerebral hyperoxia, both in the delivery suite and the NICU. This suggests that a more rapid increase in oxygen titration maybe be required initially for preterm infants.