ECMO for patients with obesity: evidence and practice

Obesity is increasingly encountered among patients requiring extracorporeal membrane oxygenation (ECMO) for severe respiratory or cardiac failure. It alters respiratory and cardiovascular physiology and drug pharmacokinetics and introduces technical and logistical challenges that may complicate patient selection, ECMO initiation, cannulation, anticoagulation, and monitoring. This review summarizes current evidence regarding the epidemiology, physiological implications, outcomes, and management of obesity in patients supported with veno-venous (VV) or veno-arterial (VA) ECMO.

Available evidence, largely retrospective and based on body mass index classifications, suggests that obesity should not be considered a contraindication to VV-ECMO, with outcomes comparable to or potentially better than those of patients without obesity. However, obesity-related respiratory mechanics may exaggerate the apparent severity of lung injury, emphasizing the need for optimized conventional ARDS management, including appropriate ventilatory strategies and prone positioning, before ECMO initiation. In contrast, outcomes during VA-ECMO are more heterogeneous, particularly in extracorporeal cardiopulmonary resuscitation (ECPR), and may be influenced by patient selection, comorbidities, and timing of support. Obesity also creates important technical challenges requiring individualized cannulation, anticoagulation, and perfusion strategies.

Obesity alone should not preclude access to ECMO, particularly VV-ECMO. Successful management requires anticipation of obesity-related challenges, appropriate infrastructure, and structured multidisciplinary protocols. Further prospective studies are needed to clarify obesity-specific risks, optimize management strategies, and evaluate long-term outcomes.