#3270 TRANSPORT AND HYDROLYSIS OF ICODEXTRIN DURING PERITONEAL DIALYSIS

Abstract Background and Aims α-amylase, an enzyme present in plasma peritoneal tissue, takes part the process of starch digestion. During exchange with icodextrin-based solution, polysaccharide chains are hydrolysed to shorter oligosaccharide chains, influencing osmotic properties dialysate. We estimated transport parameters compared them hydrolytic clearances using a new model that into consideration absorption icodextrin from cavity its degradation by α-amylase. Method Frequent dialysate blood samples were taken 11 patients (8 icodextrin-naïve, 3 icodextrin-exposed) undergoing 16-hour dwell studies dialysis solution labeled serum albumin (RISA) added as volume marker. Using data on intraperitoneal concentrations glucose, urea, creatinine, 7 molecular weight (MW) fractions (glucose polymer size classes) α-amylase extended three-pore was applied estimate individual related induced hydrolysis The following MW cut-off values assumed for fractions: up 1.08, 4.44, 9.89, 21.4, 43.5, 66.7 over kDa, called Fractions 1–7, respectively. defined rate at which is cleared fraction hydrolysis. time-dependent calculated diffusive ones. For first time validated not only respect water small solutes but also regarding concentration fractions. Results Mean measured simulated ratios urea creatinine presented Figure 1, left panel. kinetic (dialysate each initial concentration) mean numerical simulation results right showed provides accurate (mean relative error less than 7%) description patient kinetics including comparison (H) (PS, reflecting maximal rates their clearance diffusion) case polymers (Fractions 1–3) higher or similar ones whole time. In 4 5, domination PS slowly decreased during time, being dominated processes end exchange, least partly due changes concentration. polysaccharides 6 7, remained Interestingly, obtained H icodextrin-exposed typically below 1.2 mL/min except Fraction 6, increased value 0.83±0.30 1.43±0.64 dwell. On other hand, final icodextrin-naïve average all 5. Conclusion provided long dwells. dominate whereas 1–3.