Sodium Sieving in Children

Abstract

Sodium sieving is a consequence of dissociation between the amount of water and sodium transported over the peritoneal membrane. This dissociation occurs in the presence of aquaporin-mediated water transport. Sieving of sodium can be used as a rough measure for aquaporin-mediated water transport. Icodextrin contains glucose polymers, inducing ultrafiltration by colloid osmosis. Therefore, aquaporins play a minor role in ultrafiltration, which is confirmed by the absence of sodium sieving. Icodextrin is very suitable for the daytime dwell in children on a nightly intermittent peritoneal dialysis regimen. Ultrafiltration obtained with icodextrin is similar to ultrafiltration obtained with 3.86% glucose after a 12-hour dwell. When using icodextrin in children, it is also confirmed by the absence of sodium sieving that the aquaporins play a minor role in ultrafiltration.