Method and arrangement for determining the recirculation in a fistula or the cardiopulmonary recirculation, and a blood treatment device comprising a device for determining the fistula recirculation or the cardiopulmonary recirculation part
A method for determining the recirculation in a fistula and/or the cardiopulmonary recirculation part during an extracorporeal blood treatment is disclosed, where the blood to be treated flows in an extracorporeal blood circuit through a blood chamber of a dialyzer split by a semi-permeable membrane into the blood chamber and a liquid chamber, and dialysis liquid flows in a dialysis liquid path through the dialysis liquid chamber of the dialyzer. A device for determining the recirculation in a fistula and/or the cardiopulmonary recirculation part, and a blood treatment device including such a device are also disclosed. The method and device are based on the fact that the sum of the fistula recirculation and the cardiopulmonary recirculation part, i.e. the total recirculation, is determined for two blood flow rates which differ from each other. The fistula recirculation and/or the cardiopulmonary recirculation part are then determined from the recirculation for the two blood flow rates.
