(786) - Mechanical Ventilation of ECMO Patients Is Associated with Decreased Post-Transplant Survival

Abstract

Extracorporeal membrane oxygenation (ECMO) is an invaluable technique in the management of respiratory failure and has been increasingly utilized as a bridge to lung transplantation. There remains variation, however, in the use of mechanical ventilation while on ECMO support despite its association with decreased post-transplantation survival. It is unclear if this same effect would be observed in the ECMO population. The United Network for Organ Sharing database was queried for all lung transplants performed for adult patients in the United States on ECMO from 1/1/2008 to 12/31/2012. This population was then subdivided into patients supported with ECMO alone or ECMO with mechanical ventilation. Pre-operative demographic and clinical variables were compared. Given the relatively recent proliferation of this practice, the primary outcomes were 30-day and 1-year survival. Multivariable regression was performed to adjust for know risk factors for mortality after transplantation. In total, 149 patients who were on ECMO at the time of transplantation were identified. Of these, 56 (38%) were managed on ECMO alone, while the remaining 93 (62%) were also mechanically ventilated. Median follow up among patients surviving to the end of the study period was 367 days. Both groups were similar with regard to age, gender, and body mass index. Ventilated patients were somewhat more likely to have idiopathic pulmonary fibrosis (38% vs 30%) or cystic fibrosis (23% vs 16%), while ECMO-only patients were more likely to have chronic obstructive pulmonary disease (9% vs 5%) or primary pulmonary arterial hypertension (7% vs 0%). Pulmonary capillary wedge pressures were similar in both groups (11 mmHg), but mean pulmonary arterial pressures were higher in the ECMO-only group (33 vs 28 mmHg) with no differences in pre-transplant pO2, pCO2. Lung allocation score were similar with mean values in the low 80s. 30-day and 1-year survival were improved in the ECMO-only group (90% vs 78%, 72% vs 52%, p<0.033). These remained significant even when accounting for established predictors of mortality in regression analysis. Even in the high-acuity ECMO population, mechanical ventilation is associated with markedly decreased short term post-transplantation survival.