Predictors of outcome among patients on extracorporeal membrane oxygenation as a bridge to lung transplantation

Background: There is a lack of data regarding clinical variables associated with successful bridge to lung transplantation (LT) using extracorporeal membrane oxygenation (ECMO) support. Methods: We reviewed the institutional database for patients supported with veno-venous (VV) or veno-arterial ECMO as a bridge to LT (n=25; mean age: 50.6±14.2 years). We recorded clinical and laboratory variables, findings on echocardiogram and development of organ dysfunction along with hospital and one-year survival. Variables were compared between patients successfully bridged to LT versus those who were not. Results: The most common diagnostic group was interstitial lung disease (18/25, 72%). VV-ECMO was used in the majority (84%). Fifteen patients (60%) were successfully bridged to LT, and the majority were alive at 1 year (14/15, 93.3%). The presence of right ventricular systolic dysfunction on pre-ECMO echocardiogram was associated with increased risk of unsuccessful bridging (OR, 95% CI: 2.67, 1.01-6.99, P=.041). While on ECMO, trough albumin levels <2.5 gm%, peak blood urea nitrogen levels >35 mg/dL and positive fluid balance were also associated with failure to bridge to LT. Conclusions: Among patients awaiting LT, the presence of RV systolic dysfunction before ECMO initiation along with worsening renal functions, low albumin levels, and volume overload is associated with poor outcomes.