Device to determine the intravasal blood volume during hemodialysis

摘要

In the device, the integral ion transfer from blood into the dialysis fluid is determined by means of an arrangement for measuring the relative conductivity. From the values obtained from the arrangement for measuring the relative conductivity, and from the conductivity of the fresh dialysis fluid, and the blood flow and the performance parameters of the dialyser (3), the plasma conductivity and the change in the plasma and blood conductivity is determined. The haematocrit level is then calculated during the dialysis, and from the haematocrit level a conclusion is drawn regarding the change in the intravasal blood volume, and the ultrafiltration rate is determined as a function of the change in the intravasal blood volume. In the haemodialysis device, upstream of the dialyser (3), a first conductivity-measuring facility (15) is arranged in the blood path (13) and is connected to an evaluation unit (18), the evaluation unit (18), in accordance with the procedure, determining the change in the intravasal blood volume, and a control unit (20) controlling the pumps (12, 14) and the dialysis fluid mixing facility (7) in accordance with the values obtained. IMAGE