Preterm Infant Outcomes after Randomization to Initial Resuscitation with FiO₂ 0.21 or 1.0

To determine rates of death or neurodevelopmental impairment (NDI) at 2 years corrected age (primary outcome) in children <32 weeks' gestation randomized to initial resuscitation with a fraction of inspired oxygen (FiO₂) value of 0.21 or 1.0.

Blinded assessments were conducted at 2-3 years corrected age with the Bayley Scales of Infant and Toddler Development, Third Edition or the Ages and Stages Questionnaire by intention to treat.

Of the 290 children enrolled, 40 could not be contacted and 10 failed to attend appointments. Among the 240 children for whom outcomes at age 2 years were available, 1 child had a lethal congenital anomaly, 1 child had consent for follow-up withdrawn, and 23 children died. The primary outcome, which was available in 238 (82%) of those randomized, occurred in 47 of the 117 (40%) children assigned to initial FiO₂ 0.21 and in 38 of the 121 (31%) assigned to initial FiO₂ 1.0 (OR, 1.47; 95% CI, 0.86-2.5; P = .16). No difference in NDI was found in 215 survivors randomized to FiO₂ 0.21 vs 1.0 (OR, 1.26; 95% CI, 0.70-2.28; P = .11). In post hoc exploratory analyses in the whole cohort, children with a 5-minute blood oxygen saturation (SpO₂) <80% were more likely to die or to have NDI (OR, 1.85; 95% CI, 1.07-3.2; P = .03).

Initial resuscitation of infants <32 weeks' gestation with initial FiO₂ 0.21 had no significant effect on death or NDI compared with initial FiO₂ 1.0. Further evaluation of optimum initial FiO₂, including SpO₂ targeting, in a large randomized controlled trial is needed.

Australian and New Zealand Clinical Trials Network Registry ACTRN 12610001059055 and the National Malaysian Research Registry NMRR-07-685-957.