Parallel Venovenous Extracorporeal Membrane Oxygenation Circuits for Refractory Hypoxemia in a Super-Super-Obese Patient

Abstract

VENOVENOUS EXTRACORPOREAL MEMBRANE OXYGENATION (VV ECMO) represents a rescue form of life support for refractory respiratory failure, shown to confer a mortality benefit. 1 Zhu Y Zhang M Zhang R et al. Extracorporeal membrane oxygenation versus mechanical ventilation alone in adults with severe acute respiratory distress syndrome: A systematic review and meta-analysis. Int J Clin Pract. 2021; 75: e14046 Crossref PubMed Scopus (5) Google Scholar ,2 Peek GJ Mugford M Tiruvoipati R et al. Efficacy and economic assessment of conventional ventilatory support versus extracorporeal membrane oxygenation for severe adult respiratory failure (CESAR): A multicentre randomised controlled trial. Lancet. 2009; 374: 1351-1363 Abstract Full Text Full Text PDF PubMed Scopus (2409) Google Scholar Although relative contraindications to VV ECMO have been evolving with technology and experience, they currently include mechanical ventilation for >7 days (with plateau pressure [Pplat] >30 cmH2O and/or fraction of inspired oxygen [FiO2] >90%), intracranial hemorrhage or systemic bleeding, irreversible and incapacitating central nervous system pathology, immunosuppression, terminal malignancy, and advanced age. 3 Tonna JE Abrams D Brodie D et al. Management of adult patients supported with venovenous extracorporeal membrane oxygenation (VV ECMO): Guideline from the Extracorporeal Life Support Organization (ELSO). ASAIO J. 2021; 67: 601-610 Crossref PubMed Scopus (114) Google Scholar The latest ECMO guidelines do not list obesity as a contraindication. 3 Tonna JE Abrams D Brodie D et al. Management of adult patients supported with venovenous extracorporeal membrane oxygenation (VV ECMO): Guideline from the Extracorporeal Life Support Organization (ELSO). ASAIO J. 2021; 67: 601-610 Crossref PubMed Scopus (114) Google Scholar In fact, studies support the use of VV ECMO in patients with obesity in light of similar or even better survival outcomes compared to their nonobese counterparts. 4 Lazzeri C Bonizzoli M Cianchi G et al. Body mass index and echocardiography in refractory ARDS treated with veno-venous extracorporeal membrane oxygenation. J Artif Organs. 2017; 20: 50-56 Crossref PubMed Scopus (18) Google Scholar , 5 Swol J Buchwald D Dudda M et al. Veno-venous extracorporeal membrane oxygenation in obese surgical patients with hypercapnic lung failure. Acta Anaesthesiol Scand. 2014; 58: 534-538 Crossref PubMed Google Scholar , 6 Kon ZN Dahi S Evans CF et al. Class III obesity is not a contraindication to venovenous extracorporeal membrane oxygenation support. Ann Thorac Surg. 2015; 100: 1855-1860 Abstract Full Text Full Text PDF PubMed Scopus (54) Google Scholar , 7 Al-Soufi S Buscher H Nguyen ND et al. Lack of association between body weight and mortality in patients on veno-venous extracorporeal membrane oxygenation. Intensive Care Med. 2013; 39: 1995-2002 Crossref PubMed Scopus (41) Google Scholar , 8 Zaidi SAA Saleem K. Obesity as a risk factor for failure to wean from ECMO: A systematic review and meta-analysis. Can Respir J. 2021; 20219967357 Crossref PubMed Scopus (5) Google Scholar , 9 Cho WH OH JY Yeo HJ et al. Obesity survival paradox in pneumonia supported with extracorporeal membrane oxygenation: Analysis of the national registry. J Crit Care. 2018; 48: 453-457 Crossref PubMed Scopus (15) Google Scholar , 10 Galvagno Jr., SM Pelekhaty S Cornachione CR et al. Does weight matter? Outcomes in adult patients on venovenous extracorporeal membrane oxygenation when stratified by obesity class. Anesth Analg. 2020; 131: 754-761 Crossref PubMed Scopus (24) Google Scholar However, skepticism still exists, especially for those with extreme body mass index (BMI), defined as super-obese (BMI >50) or super-super obese (BMI >60). Apart from practical challenges, such as cannulation and proning difficulties, the complex pulmonary and cardiovascular pathophysiology associated with extreme obesity carries the risk of inadequate ECMO flows for the body surface area (BSA), with resultant hypoxemia, as well as hemolysis with secondary coagulopathy from required high flows. The study authors report the successful implementation of 2 in-parallel VV ECMO circuits to overcome the limitations encountered in a super-super-obese patient undergoing conventional VV ECMO for refractory respiratory failure.