Near-infrared spectroscopy cerebral oximetry in pediatric congenital heart disease with cardiopulmonary bypass: a narrative review of current evidence and neuroprotection.

Children with congenital heart disease (CHD) often require early surgical repair supported by cardiopulmonary bypass (CPB). Although survival has improved, neurological injury and later neurodevelopmental impairment remain common, motivating continuous perioperative neuromonitoring. Near-infrared spectroscopy (NIRS) provides noninvasive, real-time regional cerebral oxygen saturation (rScO2), reflecting the balance between cerebral oxygen delivery and metabolic demand. This review summarizes evidence on NIRS-derived perioperative rScO2 patterns in pediatric CHD surgery with CPB and examines associations between cerebral oxygenation abnormalities, markers of brain injury, and neurodevelopmental outcomes. rScO2 typically increases during cooling/deep hypothermia but reaches nadirs during low-flow perfusion or circulatory arrest and in early rewarming, suggesting vulnerability windows when oxygen supply-demand mismatch is most likely. Definitions and thresholds for cerebral desaturation vary substantially across studies, yet accumulating data indicate that postoperative cerebral oxygenation-particularly mean levels and cumulative desaturation burden within the first 12-24 h-may correlate with adverse biomarkers or neuroimaging findings and poorer later cognitive performance. Hemodynamic disturbance, oxidative stress, and inflammation may further shape the relationship between rScO2 abnormalities and neurological injury risk. Overall, perioperative rScO2 trends and desaturation burden may support neurological risk stratification and individualized physiological assessment, but standardized metrics, multimodal monitoring strategies, and prospective studies with long-term neurodevelopmental endpoints are needed to define actionable targets.