“…Extracorporeal gas exchange devices, i.e., venovenous extracorporeal membrane oxygenation (ECMO) and extracorporeal carbon dioxide removal (ECCO 2 R), were developed more than 40 years ago [4,5] to rescue these dying patients. Whereas venovenous ECMO provides complete extracorporeal blood oxygenation and decarboxylation using high blood flows (4-6 l/min) and large (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) cannulas [6][7][8][9], efficient extracorporeal CO 2 removal (with minimal blood oxygenation) can be achieved with ECCO 2 R devices using limited extracorporeal blood flow (0.4-1 l/min) and thin double lumen venous catheters (14)(15)(16)(17)(18) [10,11], because CO 2 clearance is more effective than oxygenation due to the greater solubility and more rapid diffusion of CO 2 [12]. Extracorporeal gas exchange devices also permit 'ultraprotective' mechanical ventilation with further reduction of volume and pressure, which may ultimately enhance lung protection and improve clinical outcomes for patients with acute respiratory distress syndrome (ARDS).…”