Kinetic Modeling as a Prescription Aid in Peritoneal Dialysis

Abstract

Methods for calculating fluid and mass removal in peritoneal dialysis are presented in order to aid clinicians in their care and management of patients and to assist them in their understanding of the physiological mechanisms which govern peritoneal transport. These methods are based on the Pyle-Popovich peritoneal mass transport model which encompasses both diffuse and convective transport as well as lymphatic flow and residual renal function. Algebraic solutions to the mass balance equations governing solute transport are provided. Since these solutions are expressed explicitly as functions of time, they are easily programmed for use on a personal computer or calculator. This offers considerable advantage over the more computer-intensive numerical solutions which had been previously required since one can now calculate both mass removal and changes in blood concentration at the end of an exchange without requiring any intermediate calculations. This computational advantage and the ability to model changes in blood concentration are shown to be of particular importance when modeling more dynamic therapies such as CCPD or Tidal peritoneal dialysis. Finally, the model and solutions, when assessed clinically among 5 patients on two separate occasions, resulted in predicted fluid and mass removals which were in high concordance with measured fluid and mass removals (concordance correlation coefficients in excess of 0.97). Our findings suggest that kinetic modeling can provide the kind of analytical tools necessary to guide clinicians in their care and management of peritoneal dialysis patients.

Comparisons of the Peritoneal Equilibration Test and Ultrafiltration in Patients with and without Diabetes Mellitus on Continuous Ambulatory Peritoneal Dialysis

“…Residual, intraperitoneal and net UF volumes were calculated sequentially by standard methods [1,7,8,9,10]. Formulas are listed in table 1.…”

Biochemical Parameters, Nutritional Status and Efficiency of Dialysis in CAPD and CCPD Patients

“…Since CCPD uses a greater number of exchanges with shorter dwell times and more total dialysate volume compared to CAPD, such variables may impact on the specific daily clearance of molecules of varying size and charge [1][2][3]. In addition, several lines of evidence suggest that CAPD and CCPD may differ in glucose, amino acid, and protein mass transfer [1][2][3][4][5][6].…”

Representations of Peritoneal Tissue – Mathematical Models in Peritoneal Dialysis

“…The pore model derived the description and relationships between the transport parameters from the solute size and the structure of the transport barrier (size of pores, number of pores etc.). The mentioned models of peritoneal transport were included into practical methods and computer programs for the evaluation of the efficacy and adequacy of peritoneal dialysis (Haraldsson, 2001;Van Biesen et al, 2003;Van Biesen et al, 2006;Vonesh et al, 1991;Vonesh &Keshaviah, 1997;Vonesh et al, 1999). In this chapter these two most popular models describing peritoneal transport of fluid and solutes were presented and compared as regards their basic ideas and aims as well as their applicability.…”