Objective: The use of extracorporeal membrane oxygenation (ECMO) has increased exponentially. Costs and outcomes, however, vary considerably by indication. We sought to elucidate and quantify these differences.
Methods: Adult patients supported on ECMO between 2008 and 2016 were analyzed using the Nationwide Inpatient Sample. We divided the study period into an early (2008-2013) and late period (2013-2016). The primary outcome was hospital charges, and the secondary outcomes were mortality, length of stay (LOS), and duration of ECMO support. These were stratified by the 5 most common indications: postcardiotomy shock (PCS), cardiogenic shock (CS), severe acute respiratory failure (SARF), heart (HT), and lung transplantation (LT). Both patient and hospital characteristics were assessed. Charges were adjusted for inflation and analyzed using a generalized linear model with gamma distribution. Pairwise comparison with Bonferroni correction was used to evaluate the cost and multivariate logistic regression to assess the risk of mortality.
Results: Data pertaining to 15,829 adult patients were evaluated. Mean age of the entire cohort was 52.8 years, 8895 (56%) were white, and 10,278 (65%) were male. PCS was the predominant indication for ECMO (39%), followed by CS (37%). SARF accounted for 15% and HT and LT accounted for 3.9% and 5.4%, respectively. Mean LOS and duration of ECMO support were 23.4 days and 5.3 days respectively. Mean hospital charges per hospitalization for the entire cohort were USD 731,914 per patient. Charges per patient pertaining to hospitalizations in which ECMO was used in transplant patients were the highest: USD 1,448,931 and USD 1,574,378 (P = .99) for HT and LT, respectively. Charges were lower for the other indications: PCS USD 798,909, CS USD 655,099, and SARF USD 824,852. Overall mortality for the entire cohort was 55%. PCS and CS (53% vs 58%, P = .34) had similar survival, whereas SARF was 45%, LT was 39% and HT 32%. There were no differences in survival in these latter indications (SARF, LT and HT). The cumulative charges (proportion × hospital charges) reveal that PCS and CS (39% and 37%) account for both the majority of charges as well as the greatest mortality. Conversely, SARF and transplantation accounted for the smaller proportion of charges and the lower mortality. Patients undergoing HT had the longest LOS (51.7 days) and duration on ECMO (15.9 days), followed by LT (35.4 and 8.8 days respectively), and patients with SARF (28.6 and 6.6 respectively). LOS and duration of ECMO for those with PCS were 18.7 days and 4.8 days, respectively. Those on ECMO for CS were hospitalized for 19.7 days and spent an average of 3.8 days on ECMO. Mortality decreased, whereas charges increased in the late era.
Conclusions: The use of ECMO is associated with high hospital charges and a wide variation in outcomes. Hospitalizations, in which ECMO is used to support patients with cardiogenic shock (PCS and CS), are individually associated with lower LOS and charges. Cumulatively, however, these account for greater charges and greater mortality. Although mortality may be decreasing, overall charges are increasing with time. These variations may influence reimbursement decisions in value-based healthcare.
Keywords: ARF, acute respiratory failure; CS, cardiogenic shock; ECMO; ECMO, extracorporeal membrane oxygenation; HT, heart transplant; ICD-9, International Classification of Diseases; IHM, in-hospital mortality; LOS, length of stay; LT, lung transplant; NIS, Nationwide Inpatient Sample; PCS, postcardiotomy shock; SARF, severe acute respiratory failure; USD, United States Dollars; charges; mortality; outcomes.
© 2020 by The Authors. Published by Elsevier Inc. on behalf of The American Association for Thoracic Surgery.