Clinical research study: cerebral autoregulation in neonates and infants undergoing open heart surgery: global patterns and derived cerebral hemodynamic metrics

Abstract

Background: Optimal perfusion pressure targets during cardiopulmonary bypass in children are debated. Monitoring of CAR allow determination of optimal perfusion pressures, but its feasibility within a large cohort of children warrants further investigations.

Methods: Prospective, single center, observational study. Cerebral Oxygenation Index (COx) was calculated as a moving linear correlation coefficient between slow waves of mean arterial pressure (MAP) and cerebral oxygenation saturation. Postoperative outcomes were recorded and associations with CAR derived metrics were explored.

Results: Mean COx values demonstrated CAR disruption during CPB (0.17 ± 0.17 before vs. 0.36 ± 0.13 during, p < 0.001). Post-CPB, CAR restored partially (mean Cox 0.32 ± 0.16, p < 0.05). Factors associated with CAR Disruption were age at surgery and average hematocrit during CPB. MAPopt determination was feasible in 83.3%, 75.4%, and 67.5% of patients before, during, and after surgery, respectively. LLA was determined in 78.1%, 53.5%, and 56.1%, and ULA in 71%, 50%, and 57% during the same time frames. Dose of MAP below LLA during CPB was independently associated with pre-postoperative serum creatinine ratio and 24 h postoperative serum lactate levels.

Conclusions: The findings highlight the clinical significance of CAR monitoring, with implications for optimizing cerebral and systemic perfusion in this vulnerable population.

Impact: In most cases, cardiopulmonary bypass is associated with CAR disruption, highlighting the need for rigorous perfusion pressure management. Individualized determination of optimal MAP target is feasible in neonates and infants undergoing cardiopulmonary bypass using CAR-derived metrics. The time spent within a range of optimal pressure is associated with better body perfusion. Live determination of optimal MAP may be used to develop individualized PAM management interventions, and ultimately improve body perfusion including the brain.