Introduction: Blood transfusion is nearly ubiquitous in extracorporeal membrane oxygenation (ECMO), yet its independent association with outcomes, particularly when comparing veno-arterial (VA) and veno-venous (VV) modalities, remains poorly defined on a national scale. We sought to determine the differential transfusion requirements and associated mortality between VA and VV ECMO after rigorously adjusting for patient- and hospital-level confounders. Methods: This retrospective cohort study used the National Inpatient Sample from 2019 to 2022. Adult patients undergoing either VA or VV ECMO were identified. We created a propensity score for receiving VA ECMO based on 21 demographic, clinical, and hospital covariates. Using inverse probability of treatment weighting (IPTW), we generated a balanced, nationally representative cohort to compare transfusion incidence and in-hospital mortality. A multivariable logistic regression model with an interaction term was used to assess the association of ECMO type and transfusion with mortality. The final abstract was edited using Grammarly. Results: An estimated 78,480 adult ECMO procedures occurred annually, with VA ECMO comprising 40.3% of cases. Annually, an estimated 110,950 units of blood products are transfused in ECMO patients. In a cohort of 9,676 patients with complete data, propensity score weighting successfully balanced all baseline covariates. In this weighted analysis, VA ECMO was associated with a significantly higher rate of transfusion (76.7% vs. 68.6%; OR 1.51, 95% CI 1.38-1.66, p< 0.001) and higher in-hospital mortality (47.9% vs. 39.5%) compared to VV ECMO. Conclusions: In this extensive, nationally representative study, patients on VA ECMO have 51% higher odds of receiving a blood transfusion and face a greater risk of in-hospital death compared to VV ECMO patients, even after accounting for differences in baseline clinical severity. Given the high national utilization of blood products, these findings highlight a critical need for modality-specific blood conservation strategies and further research into mitigating the high transfusion burden inherent to VA ECMO support.
Castillo et al. (Sun,) studied this question.