Purpose

The Brain Oxygenation-II study (BOx-II) is a phase-II, multicenter, single-arm clinical trial evaluating interventions based on near-infrared spectroscopy (NIRS) monitoring of cerebral oxygen saturation in extremely premature infants. Enrolled infants will follow a treatment guideline to maintain cerebral oxygen saturation in a target range within the first 72 hours of life. The primary outcomes will include interventions used to maintain cerebral saturation in target range, rates of cerebral hypoxia and systemic hypoxia, and a composite of death or severe brain injury detected on term-equivalent magnetic resonance imaging.