The effect of selective cerebral perfusion on cerebral versus somatic tissue oxygenation during aortic coarctation repair in neonates and infants

Abstract

Background: Suboptimal tissue perfusion and oxygenation may be the root cause of certain perioperative complications in neonates and infants having complicated aortic coarctation repair. Practical, effective, and real-time monitoring of organ perfusion and/or tissue oxygenation may provide early warning of end-organ mal-perfusion.

Methods: Neonates/infants who were scheduled for aortic coarctation repair with cardiopulmonary bypass (CPB) and selective cerebral perfusion (SCP) from January 2015 to February 2017 in Children's Hospital of Nanjing Medical University participated in this prospective observational study. Cerebral and somatic tissue oxygen saturation (SctO₂ and SstO₂) were monitored on the forehead and at the thoracolumbar paraspinal region, respectively. SctO₂ and SstO₂ were recorded at different time points (baseline, skin incision, CPB start, SCP start, SCP end, aortic opening, CPB end, and surgery end). SctO₂ and SstO₂ were correlated with mean arterial pressure (MAP) and partial pressure of arterial blood carbon dioxide (PaCO₂).

Results: Data of 21 patients were analyzed (age=75±67 days, body weight=4.4±1.0 kg). SstO₂ was significantly lower than SctO₂ before aortic opening and significantly higher than SctO₂ after aortic opening. SstO₂ correlated with leg MAP when the measurements during SCP were (r=0.67, p<0.0001) and were not included (r=0.46, p<0.0001); in contrast, SctO₂ correlated with arm MAP only when the measurements during SCP were excluded (r=0.14, p=0.08 vs. r=0.66, p<0.0001). SCP also confounded SctO₂/SstO₂'s correlation with PaCO₂; when the measurements during SCP were excluded, SctO₂ positively correlated with PaCO₂ (r=0.65, p<0.0001), while SstO₂ negatively correlated with PaCO₂ (r=-0.53, p<0.0001).

Conclusions: SctO₂ and SstO₂ have distinct patterns of changes before and after aortic opening during neonate/infant aortic coarctation repair. SctO₂/SstO₂'s correlations with MAP and PaCO₂ are confounded by SCP. The outcome impact of combined SctO₂/SstO₂ monitoring remains to be studied.

Keywords: Aortic coarctation repair; Cerebral tissue oxygen saturation; Neonates and infants; Somatic tissue oxygen saturation, prospective cohort study.