Near-infrared spectroscopy (NIRS) functions in a manner similar to pulse oximetry, using the difference in absorptive qualities of oxy- and deoxyhemoglobin to infrared light to quantify the percent saturation. There is also available evidence shows that tissue oximetry is sensitive and has a quicker response to physiological derangement, such as bradycardia, in preterm newborns. Additionally, it is demonstrated that reduced postoperative cerebral tissue oxygenation index variability in neonatal survivors of congenital heart disease surgery with poor neurodevelopmental outcomes. The SafeBoosC phase II randomized clinical trial hypothesizes that the burden of hypo- and hyperoxia can be reduced, and consequently the risk of brain injury, by the combined use of close monitoring of the cerebral rStO2 and an evidence-based treatment guideline to correct deviations in rStO2 outside a predefined target range. In this study, we will monitor 2 different tissue beds including cerebral and abdominal somatic tissue rStO2 and SpO2 in neonates. Further research is needed to investigate clinical implications for using this measure to drive therapeutic interventions.