key: cord-1020827-d533s9f0
authors: Ferraris, Victor A.
title: Commentary: Respiratory Failure in Patients with COVID-19 Infection – Can ECMO Help?
date: 2021-11-08
journal: J Thorac Cardiovasc Surg
DOI: 10.1016/j.jtcvs.2021.11.003
sha: c2edfc620a6fe8237ea1abc7618fd508230cf03c
doc_id: 1020827
cord_uid: d533s9f0

nan

ECMO may improve survival in certain COVID-19 patients with intractable respiratory failure, but patient selection and procedure outcomes need better definition. Clinical findings suggest that ARDS from influenza is different than ARDS associated with COVID-19. In one study, crude in-hospital mortality was significantly higher in a COVID-19 cohort with respiratory failure compared to a patient cohort with influenza-related respiratory failure (65.6% (n = 21/32) versus 36.3% (n = 11/28, p = 0.041). (2) . The adjusted hazard ratio over sixty days for COVID-19 patients was 2.81 (95% CI 1.07, 7.35) after adjusting for age, race, ECMO-associated organ failure, and Charlson Comorbidity Index. These preliminary findings with a fairly large patient J o u r n a l P r e -p r o o f cohort suggest that COVID-19 respiratory failure may have some unique features that portend worse outcomes from ARDS compared to other infectious agents.

To be fair, not all studies suggest differences in patient outcomes from respiratory failure between influenza and COVID-19 infections. In one study, 35 patients with ARDS were selected for V-V ECMO support out of 1,849 adult ICU patients with COVID-19 infection (1.9% incidence; 95% CI, 1.3-2.6%).(3). This represents 46 (95% CI, 34-61) expected V-V ECMO patients per 100,000 COVID-19 patients with respiratory failure.(4) In this study, there was no significant difference in survival between patients with COVID-19 related ARDS and Influenzarelated ARDS. It is likely that the criteria for ECMO in this study differed significantly compared to other reports of the use of ECMO for COVID-19 respiratory failure. For example, another contemporary study evaluated ECMO outcomes in patients with refractory ARDS associated with COVID-19 compared to respiratory failure from non-COVID-19 causes. (5) This study found no differences in outcomes between COVID-19 related respiratory failure treated with ECMO compared to non-COVID patients with refractory respiratory failure from multiple causes. This study emphasized the early use of ECMO in refractory respiratory failure in COVID-19 patients, especially since delay in institution of ECMO was nearly always fatal in this study.

It seems likely that, as more experience with refractory COVID-19 respiratory failure is gained, then other advanced supportive options beyond V-V ECMO will be used. Importantly, as experience with ECMO in COVID-19 patients expands, there is a suggestion that V-V ECMO may not provide the best supportive option in some COVID-19 patients. One study found that J o u r n a l P r e -p r o o f 14 COVID-19 patients with respiratory failure out of a cohort of 78 patients with COVID-related ARDS required conversion of V-V ECMO to V-A ECMO or to hybrid ECMO. (6) Likewise, there may be other non-ECMO interventions that will modify COVID-19

infections and improve outcomes associated with advanced interventions like ECMO. For example, there is a trial ongoing that will evaluate the efficacy of cytokine adsorption in COVID-19 patients as an adjunct to limit progressive organ damage from advanced COVID-19

infections.(4) This type of adjunctive therapy during ECMO support may limit organ damage during aggressive support with other measures like ECMO. It seems likely that better definition of indications for, and choice of, supportive options for complicated COVID-19 respiratory failure will surface as experience evolves.

Given the current state of our knowledge of the treatments for respiratory failure in COVID-19 patients, it seems likely that better treatment algorithms and possibly better use of advanced supportive options will surface as the pandemic progresses. At present, further critical well-designed studies are needed to supplement existing knowledge.

J o u r n a l P r e -p r o o f

Venovenous Extracorporeal Membrane Oxygenation in patients with COVID-19 respiratory failure

Comparative outcomes between COVID-19 and influenza patients placed on veno-venous extracorporeal membrane oxygenation for severe ARDS

Outcome of acute respiratory distress syndrome requiring extracorporeal membrane oxygenation in Covid-19 or influenza: A single-center registry study

The Use of Venovenous Extracorporeal Membrane Oxygenation in COVID-19 Infection: One Region's Comprehensive Experience

Outcomes after extracorporeal membrane oxygenation support in COVID-19 and non-COVID-19 patients

Transition from Simple V-V to V-A and Hybrid ECMO Configurations

Membranes (Basel)