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

Abstract

In-hospital mortality of adult veno-venous extracorporeal membrane oxygenation (V-V ECMO) patients remains invariably high. However, little is known regarding timing and causes of in-hospital death, either on-ECMO or after weaning. The current review aims to investigate the timing and causes of death of adult patients during hospital admittance for V-V ECMO, and to define the V-V ECMO gap, which is represented by the patients that are successfully weaned of ECMO but still die during hospital stay. A systematic search was performed using electronic MEDLINE and EMBASE databases through PubMed. Studies reporting on adult V-V ECMO patients from January 2006 to December 2020 were screened. Studies that did not report on at least on-ECMO mortality and discharge rate were excluded from analysis as they could not provide the required information regarding the proposed V-V ECMO-gap. Mortality rates on-ECMO and after weaning, as well as weaning and discharge rates, were analyzed as primary outcomes. Secondary outcomes were the causes of death and complications. Initially, 35 studies were finally included in this review. Merely 24 of these studies (comprising 975 patients) reported on prespecified V-V ECMO outcomes (on-ECMO mortality and discharge rate). Mortality on V-V ECMO support was 27.8% (95% confidence interval (CI) 22.5%-33.2%), whereas mortality after successful weaning was 12.7% (95% CI 8.8%-16.6%, defining the V-V ECMO gap).72.2% of patients (95% CI 66.8%-77.5%) were weaned successfully from support and 56.8% (95% CI 49.9%-63.8%) of patients were discharged from hospital. The most common causes of death on ECMO were multiple organ failure, bleeding, and sepsis. Most common causes of death after weaning were multiorgan failure

Outcomes of Extracorporeal Membrane Oxygenation (ECMO) for COVID-19 Patients: A Multi-Institutional Analysis

“…However, 10.4% (11 of 106) of these patients died in the ICU after ECMO weaning and decannulation. A similar finding was published in a systemic review by Heuts et al [ 26 ], where 12.7% of the deceased patients died in the ICU after VV-ECMO weaning and before discharge. Similar results were recently published by Lorusso et al [ 9 ] in large, multi-national COVID-19 ECMO patient group, where they reported 19% in-hospital mortality after ECMO weaning and 50% overall in-hospital mortality.…”

“…Instead, they are surrogates for critical illness and indeed, signify a worse prognosis. Inevitably, whenever required, CVVH combined ECMO therapy is effective and should be established [ 11 , 25 , 26 ]. Sepsis will sooner or later develop in many patients under prolonged ICU stay, although reports of bacteremia in COVID-19 patients on ECMO are scarce and lack statistical power [ 2 , 3 , 4 , 25 ].…”

ECMO support for postoperative Total anomalous pulmonary venous connection: A single-center retrospective study

“…Other potential causes include bleeding complications, sepsis, multiple organ failure, etc. [20,21]. Right ventricular contractile support, pulmonary vasodilators, diuretics, and inodilators may be utilized as adjunctive therapies.…”

Current and future strategies to monitor and manage coagulation in ECMO patients

“…The most frequent complications and one of the common causes of death for patients on ECMO are thrombus formation and bleeding [ 5 , 6 ]. The risk of bleeding is related to patient-specific and treatment-related factors associated with ECMO.…”