EQUILIBRATION OF PERITONEAL-DIALYSIS SOLUTIONS DURING LONG-DWELL EXCHANGES

Abstract

There is an increasing interest in CAPD [continuous ambulatory peritoneal dialysis] for the treatment of chronic uremia. This technique uses long-dwell peritoneal exchanges lasting 4 h or more. Equilibration curves were determined for multiple solutes during long exchanges with commercially available 1.5% and 4.25% dextrose dialysis solutions. For small solutes, rates of changes of D/P ratios [dialysate/plasma concentration ratio] fall off dramatically after 3 h of dwell time. For larger solutes, D/P ratios change more linearly. Some concentration gradients for net removal by diffusion persist well beyond 4 h for all but the most highly diffusible solutes. Previously reported net sieving of Na+ and Cl- during hypertonic exchanges is still evident after many hours.