The present invention generally relates to a process suitable for extracorporeal lung support. The process relies on exposing blood, separated by a semipermeable membrane from the dialysis liquid. The dialysis liquid of the present invention comprises a buffering agent and has a high buffering capacity for H* ions. Carbon dioxide, bicarbonate and hydrogen cations can be efficiently transported across a semipermeable membrane to the dialysis liquid. The present invention also allows for the regeneration and recycling of the dialysis liquid, and thus for its recycling and repeated use. The versatility of the dialysis liquid allows to adjust the pH of the dialysis liquid, add fluids to the dialysis liquid and/or to the blood in the extracorporeal circuit and to remove substances from the blood in the extracorporeal circuit, depending on the conditions and needs. Thus, the present invention is versatile, and suitable for treating or preventing respiratory acidosis, metabolic acidosis, diseases associated with lung malfunction and/or kidney malfunction and/or liver malfunction. For example, when the kidney function is limited, the acid-base balance of the blood can be provided by the method of the present invention and when the liver function is limited, toxins can be removed from blood by the method of the present invention.
