Understanding the ”Extra-Corporeal Membrane Oxygenation Gap" in Veno-Arterial Configuration for Adult Patients: Timing and Causes of Death. Defining the Veno-Arterial Extracorporeal Membrane Oxygenation Gap

Abstract

Background Timing and causes of hospital mortality in adult patients undergoing veno-arterial extracorporeal membrane oxygenation (V-A ECMO) have been poorly described. Aim of the current review was to investigate the timing and causes of death of adult patients treated with V-A ECMO, and subsequently define the “V-A ECMO gap”, which represents the patients who are successfully weaned of ECMO but eventually die during hospital stay.Methods A systematic search was performed using electronic MEDLINE and EMBASE databases through PubMed. Studies reporting on adult V-A ECMO patients from January 1993 to October 2018 were screened. Timing, rates and causes of in-hospital mortality were analyzed.Results Sixty studies with 9,181 patients were included in this systematic review. Overall mortality was 37.6% during V-A ECMO support (reported by 60 studies) and 28.9% (57 studies) after weaning. Finally, 32.6% were discharged from hospital (60 studies). Most common causes of death on ECMO were multiple organ failure (MOF, 49.8%), followed by cardiac failure (20.6%) and neurological causes (15.7%). Most common causes of death after weaning were MOF (55.3%), followed by neurological complications (12.6%), persistent heart failure (10.7%) and pulmonary infections (6.8%).Conclusions More than one-third of adult V-A ECMO patients die during ECMO therapy. Additionally, almost one half of successfully weaned patients still decease during hospital stay, defining the “V-A ECMO gap”. Underreporting and lack of uniformity in reporting of important parameters remains problematic in ECMO research. Future studies should uniformly define timing and causes of death in V-A ECMO patients to better understand the effectiveness and complications of this therapy. Systematic review registration PROSPERO 2019 number CRD42019130815

Defining and understanding the “extra‐corporeal membrane oxygenation gap” in the veno‐venous configuration: Timing and causes of death

“…As such, mortality and timing of mortality (either on‐ECMO or after weaning) of V‐V ECMO patients is still not fully elucidated. Although less well pronounced as in V‐A ECMO, 11 we still observe a relatively large group of patients that decease despite successful weaning from ECLS in V‐V ECMO patients. In a previously published review of V‐A ECMO patients by our research group, 11 this discrepancy was identified as the ECMO gap , which can also be applied to patients undergoing V‐V ECMO: the V‐V ECMO gap .…”