COVID in the ICU: Can Patients Be Too Obese for ECMO?

— Florida hospital's experience goes against received wisdom

Last Updated October 22, 2021
MedicalToday

Published guidelines recommend against extracorporeal membrane oxygenation (ECMO) for morbidly obese COVID-19 patients in severe distress, but a Florida researcher said his center's experience indicates that such advice needs another look.

At Advent Health Orlando, mortality in COVID patients with acute respiratory distress syndrome (ARDS) and body mass index (BMI) values above 40, while not good, was no worse than previously reported for all critically ill COVID patients in a large database, said Sergio Ramirez, MD, a critical care fellow now at Orlando Regional Medical Cente.

Speaking at , the American College of Chest Physicians' annual meeting, held online this year, Ramirez said centers participating in the Extracorporeal Life Support Organization (ELSO), which issued the in the morbidly obese, should "consider not using BMI as a sole exclusion criteria [sic] for candidacy to ECMO support."

ELSO released the guideline in May 2020 after reviewing more than 100 published papers related to ECMO; most of those did not address COVID-19 specifically, of course, since the novel coronavirus had only emerged a few months previously. The guideline included BMI >40 in a list of "relative contraindications" that also included age >65, advanced systolic heart failure, and immune deficiency, among others.

Faced with an onslaught of COVID-19 patients with high BMI values, Advent Health Orlando set its own ECMO eligibility criteria that allowed morbidly obese patients to receive the treatment if it wasn't otherwise contraindicated. At CHEST, Ramirez reported outcomes for these patients treated from March 2020 to April 2021.

A total of 33 patients with BMI >40 underwent ECMO at the Orlando center. Of these, 11 died while on ECMO, and one other died in hospital after surviving ECMO, for an overall mortality rate of 36%. Nineteen were either transferred to another hospital or discharged to home or a rehab facility and were considered to be ECMO survivors (57%); two of the 33 remained at the Orlando center at data analysis with their final status uncertain.

Although the 36% mortality rate was disappointing, it matched up closely with in September 2020 for COVID/ARDS patients with BMI values <37, Ramirez noted. This analysis covered 1,035 patients in 36 countries, yielding an estimated 90-day mortality rate of 37%.

Similarly, the ELSO data showed a survival rate of 60%.

Other highlights of the Orlando experience with morbidly obese patients included:

  • Age was not a factor in survival probability
  • Those who survived spent as long on ECMO as those who died
  • Overall hospital stays were longer in survivors, not unexpectedly

Ramirez acknowledged that his analysis should not be the last word, however; he called for additional research on ECMO for patients with high BMI values.

  • author['full_name']

    John Gever was Managing Editor from 2014 to 2021; he is now a regular contributor.

Disclosures

Ramirez and co-authors said they had no relevant financial interests.

Primary Source

CHEST

Ramirez S, et al "Successful use of extracorporeal membrane oxygenation (ECMO) in morbidly obese patients" CHEST 2021.