"Awake" Extracorporeal Membrane Oxygenation as a Bridge to Lung Transplant

Abstract

The outcomes of patients bridged to lung transplant using extracorporeal membrane oxygenation (ECMO) have substantially improved in the last decade. Dual lumen cannula has revolutionized ECMO management by allowing patients to remain awake and ambulate while on ECMO support. The United Network for Organ Sharing (UNOS) database was queried for adult patients undergoing isolated lung transplantation between January 2010 and December 2018. The study population was classified based on ECMO or mechanical ventilation (MV) at the time of transplant and divided into 4 groups: 1) No ECMO&MV; 2) ECMO-only (ECMO without MV); 3) MV+ECMO (ECMO with MV); and 4) MV-only (no ECMO with MV). Survival comparisons and predictors of mortality were analyzed. A total of 18,055 lung transplantations were performed during the study period. 314 required ECMO-only, 480 required MV+ECMO, and 719 required MV-only. Survival was significantly worse for patients requiring MV+ECMO (HR 1.33, 95%CI 1.01-1.74, p=0.04) or MV-only (HR 1.63, 95%CI 1.27-2.09, p<0.001) compared to ECMO-only. There was no significant difference in survival between ECMO-only and No ECMO&MV (HR 1.02, 95%CI 0.82-1.27, p=0.88, Figure). Within the study cohort, recipient requiring MV at listing (OR 1.39, 95% CI 1.14-1.69, p=0.001), bilateral lung transplant (OR 0.58, 95%CI 0.53-0.64, p<0.001) and recipient dialysis (OR 3.31, 95%CI 2.02-5.44, p<0.001) were associated with mortality on multivariate analysis. ECMO-only (OR 0.87, 95%CI 0.68-1.13) was not a significant predictor of mortality. In subgroup analysis in ECMO cohort, MV+ECMO was associated with diabetes (p<0.001), infection requiring IV antibiotics (p=0.003), and cystic fibrosis/bronchiectasis (p<0.001). Awake ECMO is a feasible and safe option for bridge to transplant in eligible patients with end stage lung disease. The combination of ECMO and MV is associated with decrease post-transplant survival. Listing should be carefully considered in this particular clinical scenario.