Abstract
Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a life-saving intervention for individuals with refractory cardiopulmonary failure and is associated with several complications. Differential hypercapnia, also known as RIDDLER syndrome or East-West Syndrome, is a complication, at times exacerbated iatrogenically, where competitive flow dynamics lead to relative increase in carbon dioxide delivery from the descending aorta in awake patients supported with peripheral VA-ECMO. This case report presents the clinical course, diagnostic features, management, and outcome for a patient who developed differential hypercapnia during awake peripheral VA-ECMO cannulation and support.