Effect of Cerebral Oximetry-Guided Treatment on Brain Injury in Preterm Infants as Assessed by Magnetic Resonance Imaging at Term Equivalent Age: An Ancillary SafeBoosC-III Study

Introduction: The SafeBoosC-III trial investigated the effect of cerebral oximetry-guided treatment in the first 72 h after birth on mortality and severe brain injury diagnosed by cranial ultrasound in extremely preterm infants (EPIs). This ancillary study evaluated the effect of cerebral oximetry on global brain injury as assessed by magnetic resonance imaging (MRI) at term equivalent age (TEA). Methods: MRI scans were obtained between 36 and 44.9 weeks PMA. The Kidokoro score was independently evaluated by two blinded assessors. The intervention effect was assessed using the nonparametric Wilcoxon rank sum test for median difference and 95% Hodges-Lehmann (HL) confidence intervals (CIs). The intraclass correlation coefficient (ICC) was used to assess the agreement between the assessors. Results: A total of 210 patients from 8 centers were included, of whom 121 underwent MRI at TEA (75.6% of alive patients): 57 in the cerebral oximetry group and 64 in the usual care group. There was an excellent correlation between the assessors for the Kidokoro score (ICC agreement: 0.93, 95% CI: 0.91-0.95). The results showed no significant differences between the cerebral oximetry group (median 2, interquartile range [IQR]: 1-4) and the usual care group (median 3, IQR: 1-4; median difference -1 to 0, 95% HLCI: -1 to 0; p value 0.1196). Conclusions: In EPI, the use of cerebral oximetry-guided treatment did not lead to significant alterations in brain injury, as determined by MRI at TEA. The strong correlation between the assessors highlights the potential of the Kidokoro score in multicenter trials. Our study looked at whether monitoring the cerebral oxygenation by a specific tool can help protect the brains of very premature babies. We wanted to see if this tool could reduce the chances of any degree of brain injury in these tiny babies. The SafeBoosC-III was a big multicenter trial that found that using cerebral oximetry did not make a big difference in preventing severe brain injuries or saving lives in these babies. To study in more depth a representative group of babies in this big trial, we used advanced brain scans like MRI to check babies' brain health. Even though we noticed a small improvement in overall brain health when using cerebral oximetry, it was not enough to show a clear benefit. It is important to note that only one baby out of every five had severe brain injuries in the study. Our research shows that while cerebral oximetry is helpful for monitoring brain oxygen levels, it did not lead to noticeable changes in how often brain injuries happened in premature babies. This tells us that we still have more to learn about protecting these fragile babies' brains, and we need to keep looking for better ways to help them. In conclusion, our study highlights the challenges in using cerebral oximetry to prevent brain injuries in very premature babies, urging doctors and researchers to keep exploring new ideas to improve their brain health.