Prognostic Factors Associated With Intracranial Hemorrhage and Ischemic Stroke During Venovenous Extracorporeal Membrane Oxygenation: A Systematic Review

Venovenous extracorporeal membrane oxygenation (ECMO) is a life-preserving intervention for patients with respiratory failure refractory to conventional mechanical ventilation. Intracranial hemorrhage (ICH) and ischemic stroke are life-threatening complications associated with venovenous ECMO. Despite this, little is known regarding the prognostic factors associated with these adverse neurologic events. We conducted a systematic review that characterizes these predictors of ICH and ischemic stroke during venovenous ECMO. We conducted a comprehensive search of MEDLINE and Embase via the Ovid interface. We developed and performed a literature search to identify articles that evaluated ICH and ischemic stroke in adult patients undergoing venovenous ECMO. We excluded studies based on design, target population, and outcomes. Data were extracted manually by one reviewer. Risk of bias assessment was completed using the Quality in Prognostic Studies approach for each included study. Prognostic factors associated with ICH and ischemic stroke that were identified in two or more included studies were evaluated through the Grading of Recommendations, Assessment, Development, and Evaluation approach. Three hundred thirty-three studies met criteria for screening. Seventeen studies met final inclusion criteria. Seventeen studies addressed predictors of ICH. Five studies demonstrated an increased risk of ICH with lower pH before venovenous ECMO (moderate certainty). Five studies demonstrated an increased risk of ICH with greater decreases in Paco2 pre- to post-venovenous ECMO cannulation (moderate certainty). Four studies addressed predictors of ischemic stroke; however, there were no predictors of ischemic stroke identified in two or more of the included studies. This systematic review demonstrates that abnormalities and changes in blood gas parameters from pre- to post-venovenous ECMO cannulation are probably associated with increased risk of ICH. Additional high-quality studies dedicated to probable predictors of these adverse neurologic events are crucial to understanding the pathophysiology of ICH and ischemic stroke in this population and informing clinical practice to mitigate the risk of these life-threatening events.