Modeling of Icodextrin in PD Adequest® 2.0

Abstract

Objective To validate the use of a modified three-pore model for predicting fluid transport during long dwell exchanges that use a 7.5% icodextrin solution. Design A nonrandomized, single group, repeated measures study. Patients Ten peritoneal dialysis patients underwent a single 8-hour exchange of a 7.5% icodextrin solution. All patients were naïve to icodextrin. Main Outcome Measures A modified three-pore model was used to model solute and fluid transport during each 8-hour exchange. Concordance correlation coefficients were used to estimate the level of agreement between modeled and measured values of net ultrafiltration (UF) and intraperitoneal volume. Methods Each patient underwent a modified 8-hour standard peritoneal permeability analysis using a 2-L 7.5% icodextrin exchange. Dextran 70 was added to the icodextrin solution as volume marker to estimate fluid transport kinetics. Transcapillary UF, fluid absorption, and intraperitoneal volumes were assessed via the volume marker at 0, 5, 15, 30, 60, 120, 240, 300, 360, 420, and 480 minutes. Results There was strong agreement (concordance correlation = 0.9856) between net UF as measured by the volume marker data and net UF as modeled using the modified three-pore model implemented in PD Adequest (Baxter Healthcare, Deerfield, Illinois, USA). Conclusions Net UF and intraperitoneal volumes for long dwell exchanges using a 7.5% icodextrin solution can be accurately modeled with a modified three-pore model. Steady state icodextrin plasma levels are needed to accurately predict net UF for chronic users of icodextrin.

Three-Pore Model Predictions of 24-Hour Automated Peritoneal Dialysis Therapy Using Bimodal Solutions

“…Simulated time-dependent UF profiles are shown both for 7.5% icodextrin and for a sample bimodal solution (2.27% glucose plus 7.5% icodextrin) for an average patient (that is, the average of high, high-average, and low-average transport). The UF profile for 7.5% icodextrin increases continuously with time, according with reports by others (8,11,18). The effect of added glucose is evident in the early rise of UF within the first 3 – 4 hours of the dwell.…”

“…The 3-pore model, first described by Rippe and colleagues, has been widely applied to model peritoneal fluid and solute transport with glucose-based PD solutions (16,17) and icodextrin-based Extraneal solution (11,18). Rippe and Levin (11) have used the 3-pore model to simulate UF kinetics for combined icodextrin and glucose solutions; recent work by Galach et al extended those studies by evaluating fluid and solute transport during long dwells with bimodal solutions (10).…”

Ultrafiltration Characteristics of Glucose Polymers with Low Polydispersity

“…In this report, we evaluate the effect of weight-average molecular weight on the UF characteristics of glucose polymers with low polydispersity (≤2. 3) in an experimental rabbit model (10).…”

Icodextrin Simplifies Pd Therapy by Equalizing Uf and Sodium Removal among Patient Transport Types during Long Dwells: A Modeling Study

“…Steady-state plasma concentrations of icodextrin metabolites were incorporated to consider patients who routinely use icodextrin (data on file, Baxter Healthcare Corporation). PD Adequest 2.0 was validated for UF and small solute transport (23,24) and this modified kinetic model was previously used to predict icodextrin absorption (25) and sodium removal (6,20).…”