The present invention generally relates to a process suitable for extracorporeal lung support. The process comprises contacting blood with a dialysis liquid separated by a semipermeable membrane. Oxygen is introduced into blood and/or into the dialysis liquid prior to contacting blood and dialysis liquid being separated by the semipermeable membrane. The process is versatile and allows for blood oxygenation as well as removal of at least one undesired substance occurring in the blood, selected from carbon dioxide, bicarbonate and hydrogen cations, from blood. Thereby, the present invention takes advantage of the Haldane effect in the extracorporeal contacting step. The undesired substance can be efficiently transported across a semipermeable membrane to the dialysis liquid. In contrast to extracorporeal carbon dioxide removal methods of the prior art (ECCCbR), the present invention employs a versatile dialysis liquid that allows to adjust the pH and buffering capacity of the dialysis liquid, to add fluids to the dialysis liquid and/or to the blood and to remove substances from the blood in the extracorporeal circuit, depending on the conditions and needs. The present invention also provides regeneration and recycling of the dialysis liquid, and thus for its repeated use. The present invention is suitable for treating human or animal subjects suffering from lung failure or lung disorders.La présente invention concerne dune manière générale un procédé approprié pour lassistance pulmonaire extracorporelle. Le procédé comprend la mise en contact de sang avec un liquide de dialyse séparé par une membrane semi-perméable. De loxygène est introduit dans le sang et/ou dans le liquide de dialyse avant le contact avec le sang, le liquide de dialyse étant séparé par la membrane semi-perméable. Le procédé est polyvalent et permet loxygénation sanguine ainsi que lélimination du sang dau moins une substance indésirable apparaissant dans le sang, choisie parmi le dioxyde de carbone
