Changes in autonomic function and cerebral and somatic oxygenation with arterial flow pulsatility for children requiring veno-arterial extracorporeal membrane oxygenation

Background: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) carries variability in arterial flow pulsatility (AFP).Research question: What changes in cerebral and somatic oxygenation, hemodynamics, and autonomic function are associated with AFP during VA-ECMO?Methods: This is a prospective study of children on VA-ECMO undergoing neuromonitoring. AFP was quantified by arterial blood pressure pulse amplitude and subcategorized: no pulsatility (<1 mmHg), minimal pulsatility (1 to <5 mmHg), moderate pulsatility (5 to <15 mmHg) and high pulsatility (>= 15 mmHg). CVPR was assessed using the cerebral oximetry index (COx). Cerebral and somatic oxygenation was assessed using cerebral regional oximetry (rSO(2)) or peripheral oxygen saturation (SpO(2)). Autonomic function was assessed using baroreflex sensitivity (BRs), low-frequency high-frequency (LF/HF) ratio and standard deviation of heart rate R-R intervals (HRsd). Differences were assessed across AFP categories using linear mixed effects models with Tukey pairwise comparisons. Univariate logistic regression was used to explore risk of AFP with brain injuries.Results: Among fifty-three children, comparisons of moderate to high pulsatility were associated with reductions in rSO(2) (p < 0.001), SpO 2 (p = 0.005), LF/HF ratio (p = 0.028) and an increase in HRsd (p < 0.001). Reductions in BRs were observed across comparisons of none to minimal (P < 0.001) and minimal to moderate pulsatility (p = 0.004). Comparisons of no to low pulsatility were associated with reductions in BRs (p < 0.001) and ABP (p < 0.001) with increases in SpO(2) (p < 0.001) and HR (p < 0.001). Arterial ischemic stroke was associated with higher pulsatility (p = 0.0384).Conclusion: During VA-ECMO support, changes toward high AFP are associated with autonomic dysregulation and compromised cerebral and somatic tissue oxygenation.