Electroencephalographic Findings Add Prognostic Value to Clinical Features Associated with Mortality on Venoarterial Extracorporeal Support

Background: The objective of this study was to identify clinical and continuous electroencephalogram (cEEG) variables associated with outcomes of pediatric venoarterial (V-A) extracorporeal membrane oxygenation support (ECMO). Methods: We conducted a retrospective single-center study of pediatric patients on V-A ECMO between January 1, 2015, and September 30, 2020. Serial clinical and cEEG variables were collected to assess the relationship of pre- and on-ECMO variables with hospital mortality in patients who underwent cEEG monitoring. Results: Ninety-four patients undergoing V-A ECMO had cEEG monitoring, with a hospital mortality of 43%. Nonsurvivors had significantly lower pH and higher lactate levels prior to ECMO initiation. Nineteen (20%) had seizures, with 7 (7%) developing status epilepticus. In the first 24 h patients were on ECMO, unfavorable background score and lack of cEEG variability or reactivity were associated with mortality. A multivariable model investigating in-hospital mortality that included pH and lactate level 2 h prior to ECMO initiation, presence of electrographic seizures, and asymmetry on cEEG as variables, had an area under the receiver operating characteristic curve (AUROC) of 0.8 (95% confidence interval [CI] 0.74–0.86, p < 0.02). The model for on-ECMO mortality (ECMO nonsurvivors) that included pH 2 h prior to ECMO initiation, presence of electrographic seizures, and lack of variability/reactivity at any point on cEEG as variables had an AUROC of 0.85 (95% CI 0.8–0.9, p < 0.001). Conclusions: These data demonstrate an association of evolving pre-ECMO impaired tissue oxygenation and on-ECMO neurophysiologic impairment, measured by cEEG, with mortality. They provide preliminary evidence that the timing of ECMO initiation, in relation to worsening tissue oxygenation, should be investigated further, and cEEG may be used to evaluate the potential impact on both neurologic injury and mortality.