A simplified approach to understanding urea kinetics in peritoneal dialysis.

Urea, a small molecular solute, is the candidate molecule commonly used to understand solute kinetics in both peritoneal dialysis (PD) and hemodialysis. Serum urea or serum urea nitrogen levels are used to calculate measures of dialysis adequacy and nutritional status in patients on dialysis. The kinetic behavior of this molecule is different for a continuous therapy such as PD compared with an intermittent therapy such as hemodialysis. This article presents a simplified approach to understanding urea kinetics on PD.