Measurement of peritoneal dialysis delivery in children.

We measured urea [weekly urea clearance/total body water (KT/Vurea)] and creatinine (CCr) clearances on 35 occasions in 15 stable chronic peritoneal dialysis patients to determine the feasibility and reproducibility of such measurements in children. In addition, we performed peritoneal equilibration tests (PETs) to characterize our patients' peritoneal membranes and to estimate weekly clearances. We demonstrated that dialysis delivery can be quantified by these standard measurements in children of widely varying size. Further, we found that clearances predicted from PET data were similar to measured values in all patients. However, predicted and measured values were most significantly correlated in patients with high and high-average peritoneal membrane permeability. KT/Vurea and CCr were correlated overall, but differences in scaling affected the validity of the relationship. When both clearances were scaled to weight, the correlation was closer, but still differed between PET-determined peritoneal membrane types.