Abstract and Introduction
Abstract
Background: Despite expanding use, knowledge on extracorporeal membrane oxygenation support during the COVID-19 pandemic remains limited. The objective was to report characteristics, management, and outcomes of patients receiving extracorporeal membrane oxygenation with a diagnosis of COVID-19 in France and to identify pre-extracorporeal membrane oxygenation factors associated with in-hospital mortality. A hypothesis of similar mortality rates and risk factors for COVID-19 and non–COVID-19 patients on venovenous extracorporeal membrane oxygenation was made.
Methods: The Extracorporeal Membrane Oxygenation for Respiratory Failure and/or Heart failure related to Severe Acute Respiratory Syndrome-Coronavirus 2 (ECMOSARS) registry included COVID-19 patients supported by extracorporeal membrane oxygenation in France. This study analyzed patients included in this registry up to October 25, 2020, and supported by venovenous extracorporeal membrane oxygenation for respiratory failure with a minimum follow-up of 28 days after cannulation. The primary outcome was in-hospital mortality. Risk factors for in-hospital mortality were analyzed.
Results: Among 494 extracorporeal membrane oxygenation patients included in the registry, 429 were initially supported by venovenous extracorporeal membrane oxygenation and followed for at least 28 days. The median (interquartile range) age was 54 yr (46 to 60 yr), and 338 of 429 (79%) were men. Management before extracorporeal membrane oxygenation cannulation included prone positioning for 411 of 429 (96%), neuromuscular blockage for 419 of 427 (98%), and NO for 161 of 401 (40%). A total of 192 of 429 (45%) patients were cannulated by a mobile extracorporeal membrane oxygenation unit. In-hospital mortality was 219 of 429 (51%), with a median follow-up of 49 days (33 to 70 days). Among pre-extracorporeal membrane oxygenation modifiable exposure variables, neuromuscular blockage use (hazard ratio, 0.286; 95% CI, 0.101 to 0.81) and duration of ventilation (more than 7 days compared to less than 2 days; hazard ratio, 1.74; 95% CI, 1.07 to 2.83) were independently associated with in-hospital mortality. Both age (per 10-yr increase; hazard ratio, 1.27; 95% CI, 1.07 to 1.50) and total bilirubin at cannulation (6.0 mg/dl or more compared to less than 1.2 mg/dl; hazard ratio, 2.65; 95% CI, 1.09 to 6.5) were confounders significantly associated with in-hospital mortality.
Conclusions: In-hospital mortality was higher than recently reported, but nearly half of the patients survived. A high proportion of patients were cannulated by a mobile extracorporeal membrane oxygenation unit. Several factors associated with mortality were identified. Venovenous extracorporeal membrane oxygenation support should be considered early within the first week of mechanical ventilation initiation.
Introduction
Early reports of severe manifestations of COVID-19 such as acute respiratory distress syndrome (ARDS) and acute myocardial injury have suggested a possible role for extracorporeal membrane oxygenation (ECMO) support.[1] Recent experience during the influenza A (H1N1) pandemic demonstrated the value of ECMO support for patients with severe ARDS related to influenza.[2–6] Additionally, a recent meta-analysis of patients from two major randomized controlled trials on ECMO support in severe ARDS patients showed a significant benefit of the technique for improving both morbidity and mortality.[7–9]
Several early retrospective case series showed encouraging results of ECMO support in COVID-19–related respiratory failure.[10–13] However, these case series were limited in sample size (fewer than 90 patients) and restricted to few centers. Consequently, the international report from the Extracorporeal Life Support Organization (Ann Arbor, Michigan) registry, gathering 1,035 ECMO patients from 213 centers in 36 countries, was an important landmark. The study showed an estimated in-hospital mortality of less than 40% for critically ill adults with COVID-19 treated with ECMO in a collection of self-selected and experienced centers worldwide.[14] Recently, a similar mortality rate was reported in a multicenter cohort study of 190 critically ill adults with COVID-19 who received ECMO at 35 sites across the United States.[15]
In France, 485 ECMO consoles are available in 103 academic or nonacademic, public, or private centers due to the wide interest in the technique in the country. During the first wave of the pandemic, a central system was established to coordinate national ECMO resources in France. Regional coordinators met weekly to check the national availability of consoles and circuits. Specific recommendations and algorithms were issued on ECMO indications and organization in the context of the outbreak (https://www.iledefrance.ars.sante.fr/system/files/2020-12/038_ARSIdF-CRAPS_2020-12-02_Doctrine_ECMO.pdf).[16] Collecting data on this initiative is essential to evaluate the results of our organization, to inform clinicians, and to adapt our response to the future developments of the outbreak. Therefore, the goals of our study were (1) to report characteristics, management, and outcomes of patients receiving ECMO with a diagnosis of COVID-19 in France and (2) to identify potentially modifiable variables associated with in-hospital mortality. We hypothesized that the mortality rate and risk factors would be similar for COVID-19 and non–COVID-19 patients on venovenous ECMO.
Anesthesiology. 2022;136(5):732-748. © 2022 American Society of Anesthesiologists | Lippincott Williams & Wilkins
