Evaluation of Intradialytic Solute and Fluid Kinetics

A mathematical model of solute kinetics for the improvement of hemodialysis treatment is presented. It includes a two-compartment description of the main solutes and a three-compartment model of body fluids (plasma, interstitial and intracellular). The main model parameters can be individually assigned a priori, on the basis of body weight and plasma concentration values measured before beginning the session. Model predictions are compared with clinical data obtained in vivo during 11 different hemodialysis sessions performed on 6 patients with a profiled sodium concentration in the dialysate and a profiled ultrafiltration rate. In all cases, the agreement between the time pattern of model solute concentrations in plasma and the in vivo data proves fairly good as to urea, sodium, chloride, potassium and bicarbonate kinetics. Only in two sessions was blood volume directly measured in the patient, and in both cases the agreement with model predictions was good. In conclusion, the model allows a priori computation of the amount of sodium removed during hemodialysis, and makes it possible to predict the plasma volume changes and plasma osmolarity changes induced by a given sodium concentration profile in the dialysate and by a given ultrafiltration profile. Hence, it can be used to improve clinical tolerance to the dialysis session taking the characteristics of individual patients into account, in order to minimize intradialytic hypotension.

[1]  R. Converse,et al.  Paradoxical withdrawal of reflex vasoconstriction as a cause of hemodialysis-induced hypotension. , 1992, The Journal of clinical investigation.

[2]  M. Ursino,et al.  An Algorithm for the Rational Choice of Sodium Profile during Hemodialysis , 1997, The International journal of artificial organs.

[3]  A. Guyton,et al.  Textbook of Medical Physiology , 1961 .

[4]  Ewart R. Carson,et al.  Systems model of renal dialysis Formulation, validation identification , 1982 .

[5]  G. Avanzolini,et al.  A simple mathematical model applied to selection of the sodium profile during profiled haemodialysis. , 1998, Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association.

[6]  J. Daugirdas,et al.  Handbook of Dialysis , 1988 .

[7]  M Ursino,et al.  Modeling arterial hypotension during hemodialysis. , 2008, Artificial organs.

[8]  S. L. Jindal,et al.  Clinical Physiology of Acid—Base and Electrolyte Disorders. , 1978 .

[9]  Frank A. Gotch,et al.  Principles and Biophysics of Dialysis , 1996 .

[10]  G Kimura,et al.  Model prediction of plasma volume change induced by hemodialysis. , 1984, The Journal of laboratory and clinical medicine.

[11]  A. K. Solomon,et al.  Urea reflection coefficient for the human red cell membrane. , 1985, Biochimica et biophysica acta.

[12]  G. Avanzolini,et al.  A Simple Mathematical Model of Intradialytic Sodium Kinetics: “in vivo” Validation During Hemodialysis with Constant or Variable Sodium , 1996, The International journal of artificial organs.

[13]  Dr. Morton H. Friedman.  Principles and Models of Biological Transport , 1986, Springer Berlin Heidelberg.

[14]  T. Kenner,et al.  Nature and rate of vascular refilling during hemodialysis and ultrafiltration. , 1992, Kidney international.

[15]  K. Janáček,et al.  Cell Membrane Transport , 1975, Springer US.

[16]  M. Ursino,et al.  Evidence of Profiled Hemodialysis Efficacy in the Treatment of Intradialytic Hypotension , 1998, The International journal of artificial organs.

[17]  Moncrief Jw,et al.  The consequences of physiological resistances on metabolite removal from the patient-artifical kidney system. , 1975 .