Method of determining the ratio of recirculation and / or cardiopulmonary recirculation in the fistula to the total re-circulation of the fistula recirculation and cardiopulmonary recirculation

摘要

The method according to the invention and the apparatus according to the invention are characterized in that the substitution rate QS is modified by a predefined amount upstream or downstream of the dialyzer or filter while the flow rate QFM of the liquid withdrawn through the dialyzer membrane is modified. The blood volume RBV(t) or a variable correlated with the blood volume, e.g. the hematocrit Hct(t), is determined before and after modifying the substitution rate or the flow rate of the liquid withdrawn through the dialyzer or filter membrane in order to calculate fistula recirculation RA. In addition, the total recirculation R is determined. The percentage of fistula recirculation (RA) and/or cardiopulmonary recirculation (RCP) relative to the total recirculation is calculated from the determined fistula recirculation (RA) and the sum R of fistula recirculation (RA) and cardiopulmonary recirculation (RCP).