The effect of patient obesity on extracorporeal membrane oxygenator outcomes and ventilator dependency

J Card Surg. 2020 Jun;35(6):1283-1286. doi: 10.1111/jocs.14579. Epub 2020 Apr 27.

Abstract

Objective: The effect of body habitus for patients who require extracorporeal membrane oxygenation (ECMO) support has not been well-studied and may provide insight into patient survival and outcomes. We sought to determine if there is a correlation of body mass index (BMI) with ECMO outcomes.

Methods: A retrospective chart review was performed for patients who required any form of ECMO support at our institution between 2012 and 2016. Time variables (overall hospital length of stay, intensive care, and ventilator days), and outcomes variables (ability to wean from ECMO, extubation status, hospital survival, 30-day survival) were studied. Patients were divided into cohorts based on BMI. Descriptive statistics were used to summarize data. Spearman correlation, Fisher's exact test, and independent t-test were used to assess associations.

Results: A total of 231 patients required ECMO with a mean BMI of 29 (±6.47; BMI range, 17.6-57.9). The mean BMI did not differ based on type of support provided (veno-veno ECMO [VV] vs veno-arterial [VA]). There was no difference between BMI cohorts for length of stay, time in the intensive care unit (ICU), ability to wean from ECMO, hospital survival or 30-day survival. Raw BMI did not predict if or when patients were extubated.

Conclusions: Neither obesity classification nor BMI as a continuous variable affected any of the outcome variables. Respiratory outcomes including the ability to extubate and to remain ventilator-free were also independent of patient BMI. These data suggest that extremes of body habitus alone should not be used as an exclusion criteria for consideration of ECMO support.

Keywords: critical care; extracorporeal membrane oxygenation; obesity; perfusion; ventilation.

MeSH terms

  • Adult
  • Aged
  • Body Mass Index*
  • Cohort Studies
  • Extracorporeal Membrane Oxygenation* / methods
  • Extracorporeal Membrane Oxygenation* / mortality
  • Female
  • Humans
  • Length of Stay
  • Male
  • Middle Aged
  • Obesity*
  • Retrospective Studies
  • Survival Rate
  • Treatment Outcome
  • Ventilator Weaning / statistics & numerical data*