Bleeding, Thromboembolism, and Clinical Outcomes in Venovenous Extracorporeal Membrane Oxygenation

Objectives: Bleeding and thromboembolism are common during venovenous extracorporeal membrane oxygenation. The relative frequency of these complications and their impact on clinical outcomes have not been described, and no randomized trials exist to guide anticoagulation strategies in extracorporeal membrane oxygenation. Our objective was to examine the relative frequencies of bleeding and thromboembolic events and their associations with survival among a cohort of consecutive patients receiving venovenous extracorporeal membrane oxygenation.

Design: Retrospective cohort study.

Setting: A single academic medical center.

Patients: Adult patients receiving venovenous extracorporeal membrane oxygenation and anticoagulation. Eligibility criteria for this analysis were selected to emulate the population that would be recruited for a randomized trial of anticoagulation strategies during venovenous extracorporeal membrane oxygenation. Patients were excluded if they had active bleeding or thromboembolism prior to extracorporeal membrane oxygenation initiation, a history of trauma or surgery in the 7 days prior to extracorporeal membrane oxygenation initiation, an arterial extracorporeal membrane oxygenation cannula, or if they received greater than 48 hours of extracorporeal membrane oxygenation support at another institution.

Interventions: None.

Measurements and main results: Outcomes included bleeding and thromboembolic events, duration of extracorporeal membrane oxygenation support, hospital length of stay, and in-hospital survival among 55 patients receiving venovenous extracorporeal membrane oxygenation. Bleeding events occurred in 25 patients (45.5%), and thromboembolism occurred in eight patients (14.5%). Bleeding events were associated with longer duration of extracorporeal membrane oxygenation support (p = 0.007) and worse in-hospital survival (p = 0.02). Thromboembolic events did not appear to be associated with clinical outcomes.

Conclusions: In this cohort of patients receiving venovenous extracorporeal membrane oxygenation and anticoagulation, bleeding occurred more frequently than thromboembolism and was associated with worse survival. These results highlight the need for randomized trials to evaluate the safety and efficacy of continuous IV anticoagulation among patients receiving venovenous extracorporeal membrane oxygenation.