Session SB1.2

Cardiovascular Stability and Patient-Dependent Mass Transfer during Dialysis

G Casagrande*, U Teatini, G Romei Longhena, R Fumero, ML Costantino

Politecnico di Milano
Milano, Italy

Introduction: In the last years a better patient cardiovascular stability to hemodialysis (HD) has proved to be related to therapy prescription and delivery customisation. In order to guarantee customization the development of a patient-dependent mass transfer model would play a key role. On the other hand the possibility to monitor treatment parameters would allow the calculation of indexes able to characterize the patient peculiar response to HD.
Materials and Methods: A total of 18 patients undergoing standard HD were enrolled at the Renal Unit of Caduti Bollatesi Hospital-Bollate-Milan. All HD sessions over one month were analysed. Blood volume variation and ultrafiltration rate were continuously monitored; other relevant intra-dialysis parameters (systemic pressure, heart rate, blood parameters, patient weight and treatment settings) were also monitored at scheduled times. A three-pool model of the patient undergoing HD was developed and interfaced to a dialysis HD filter model. The model was customized taking into account capillary permeability and arterial compliance variation according to patient age. The effect of different dialysis filters was also considered. Based on the recorded data the Plasma Refilling Index PRI was calculated. The relationship between PRI and systemic pressure trends was investigated. Statistical analysis of intra-individual and inter-individual PRI trend variations were performed.
Results: The developed model allowed to describe mass transfer among the different compartments in each patient and to evaluate the effects of dialysis settings variations. The outcomes of PRI calculation all over the monitored sessions, showed PRI trend to be characteristic of each patient. PRI analysis allowed the detection of symptomatic but not acute hypotension episodes, related to hypovolemy. Moreover, statistical analysis highlighted two different PRI trends during the first hour and during the rest of the treatment. PRI higher than the initial during second part of HD can be attributed to dry weight overestimation.
Conclusion: The model outputs were consistent with the clinical recorded parameters. PRI trend resulted to be distinctive of each patient, to allow the detection of symptomatic but not acute hypotension and to highlight dry weight overestimation.

(Abstract Control Number: 158)