Current aspects of extracorporeal membrane oxygenation in a tertiary referral centre: determinants of survival at follow-up.

OBJECTIVES: To describe the clinical results (both early and at follow-up) of patients currently receiving extracorporeal membrane oxygenation (ECMO) therapy for cardiac and/or pulmonary failure. To assess the effect of indications, clinical presentations and ECMO modalities on early/late clinical outcomes. To identify baseline factors associated with worse survival at follow-up.
METHODS: We reviewed the prospectively collected data of 325 patients receiving ECMO therapy at a tertiary referral centre during the 2005-2013 period. Follow-up was prospectively conducted by dedicated personnel (average: 84 ± 86 days, 100% complete). Survival was analysed by stratified Kaplan-Meier curves.
RESULTS: Veno-arterial (VA) ECMO was employed in 80% of cases (due to early graft failure (EGF) in 13% of cases, post-cardiotomy in 29%, primary cardiogenic shock in 42% for miscellaneous aetiologies, other indications in 15.4%) and veno-venous (VV) ECMO in the remainders (adult respiratory distress syndrome). In the VA and VV groups, weaning rates were 59 and 53%, survival at 30th postimplantation day was 44 and 45% and survival at the end of the follow-up was 41 and 45%, respectively. Implantation under advanced life support (ALS) occurred in 15% of cases (26% survival at 30 days). VA patients had a higher rate of thrombotic/haemorrhagic complications and of transfusion of blood products and shorter ventilation time. Worse early and follow-up survival were observed among patients aged ≥65 years, having pH ≤ 7, lactates >12 mmol/l, creatinine >200 μmol/l at implantation or receiving ECMO under ALS. No difference in survival was noted among VA vs VV patients. Patients receiving ECMO for EGF displayed better early and late survival (64% at 30 days and 53% at 6 months) than post-cardiotomy (36 and 34%, respectively), post-acute myocardial infarction (48 and 40%) and the remaining patients (46 and 45%).
CONCLUSIONS: Despite most critical baseline conditions, ECMO therapy is confirmed useful for the treatment of patients with acute cardiopulmonary failure refractory to conventional treatments. The ECMO modality (VA vs VV), as well as indications to support, identifies different patient profiles and dissimilar outcomes. Preimplantation markers of gravity and end-organ damage are useful in the stratification of expected survival. These may facilitate clinical decision-making and appropriate allocation of hospital resources.