Decreased post-operative cerebral region oxygenation saturation (crSO2) variability, a surrogate for cerebral autoregulation, correlates with poor neurodevelopmental outcomes in neonates who undergo cardiac surgery. The goal of this study is to investigate the relationship between pre- and post-operative crSO2 variability in neonates requiring neonatal cardiac surgery for congenital heart disease (CHD).
The variability of averaged 1-min crSO2 values was calculated for a minimum of 12h before and for the first 48h following cardiac surgery with cardiopulmonary by-pass in neonates between November 2019 and May 2021.
The crSO2 variability increased by 9% with each additional postnatal day in the pre-operative monitoring period (p=0.009). There was a 40% decrease in crSO2 variability between the pre-and post-operative monitoring periods (p<0.001). There were no associations between the degree of decrease in crSO2 variability and CHD classification (aortic arch obstruction or single ventricle physiology).
The crSO2 variability improves with each additional postnatal day but then decreases by almost half following cardiac surgery in neonates. We did not observe any association between pre-operative crSO2 variability and post-operative ventilator-free days, post-operative ICU days, or mortality.The long-term effects or significance of reduced crSO2 require further exploration.