Peritoneal Ultrafiltration and Serum Icodextrin Concentration during Dialysis with 7.5% Icodextrin Solution in Japanese Patients

♦ Objectives To assess the efficacy and safety of icodextrin in Japanese patients and to investigate the relationship between net ultrafiltration (UF) during the long dwell and plasma oligosaccharides. ♦ Design Open-labeled clinical trial involving patients on continuous ambulatory peritoneal dialysis (CAPD) receiving icodextrin during the 12-hour long dwell for 6 weeks, preceded by and followed by a 2-week baseline period and a follow-up period during which 1.36% glucose was used for the 8-hour long dwell. ♦ Setting A prospective, randomized multicenter study done in tertiary medical centers. ♦ Patients 18 stable patients on CAPD for 3 months or longer. ♦ Main Outcomes Measures Net UF (in milliliters), UF rate (in milliliters per hour), plasma oligosaccharides, serum osmolarity (in milliosmoles per liter), peritoneal absorption of icodextrin, and peritoneal clearances of icodextrin, creatinine, and urea were assessed. Adverse events, laboratory findings, and vital signs were also monitored. ♦ Results Long-dwell net UF (544.4 ± 96.7 mL at day 3, p < 0.001; 309.4 ± 60.7 mL at week 4, p < 0.001; and 391.7 ± 61.1 mL at week 6, p< 0.001) and UF rate (48.2 ± 38.8 mL/hour at day 3, p < 0.001; 26.9 ± 22.1 mL/hr at week 4, p < 0.002; and 35.3 ± 22.9 mL/hr at week 6, p = 0.0002) were significantly greater during the icodextrin period than at baseline (-25.9 ± 46.0 mL and -2.2 ± 22.1 mL/hr, respectively). Plasma oligosaccharides reached steady state within 2 weeks, remained stable during the treatment period, and returned to baseline level 2 weeks after discontinuation of icodextrin. Serum osmolarity increased during the use of icodextrin by approximately 5 mOsm/L. No statistically significant relationship was found between plasma oligosaccharides and net UF. Peritoneal absorption of icodextrin (36.3% ± 5.1% at day 3,42.2% ± 5.9% at week 4, and 38.0% ± 6.3% at week 6) and peritoneal clearance of icodextrin (10.1 mL/minute at day 3,10.1 mL/min at week 4, and 10.3 mL/min at week 6) showed no major change over time. Serum sodium and serum chloride both decreased by 5 mEq/L with icodextrin but remained within the normal range during the treatment period and returned to baseline levels immediately after discontinuation. No serious adverse events were observed during the study. ♦ Conclusion The results of this study do not support the hypothesis that an increased blood oligosaccharide level and the concomitant elevation in serum osmolarity have a negative impact on peritoneal UF. Therefore, the increase in plasma oligosaccharides appears to be too small to be of clinical significance.