Long daytime exchange in children on continuous cycling peritoneal dialysis: preservation of drained volume because of icodextrin use.

Daytime exchanges with glucose osmotic agents often lead to dialysate reabsorption, poor ultrafiltration (UF), positive sodium balance, and restricted purification of uremic toxins. We studied 5 anuric children on continuous cycling peritoneal dialysis (mean age: 10 years, 10 months), comparing icodextrin to a conventional glucose-based dialysate. The same fill volume (980 +/- 290 mL/m2) and the same dwell duration (720 minutes) were used with both solutions for the daytime exchange. In a crossover design, we compared 7.5% icodextrin with 1.36% glucose, and then 1.36% glucose with 7.5% icodextrin. Tolerance, net UF, sodium balance, and solute extraction were analyzed. The Student t-test for paired data was used for statistical analysis. The drained volume was 44% +/- 18% higher during icodextrin exchanges, allowing a mean enhanced sodium extraction of 44 +/- 15 mmol per daytime exchange. The uremic toxin extraction capacity was enhanced under icodextrin: weekly Kt/V urea increased by 0.41 +/- 0.1, weekly creatinine clearance increased by 8.4 +/- 3.6 L/1.73 m2, and phosphate removal increased by 23%. Similarly, beta2-microglobulin extraction increased with icodextrin use. Dialysate protein loss under icodextrin increased from 1.3 +/- 0.6 g to 1.9 +/- 0.96 g per daytime exchange. Icodextrin improved ultrafiltration and purification capacities (urea, creatinine, phosphate, beta2-microglobulin), but the large drained volume directly affected dialysate protein loss.