Measurement of peritoneal dialysis delivery in children

Abstract

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.

Clinical practice guidelines for pediatric peritoneal dialysis

“…Twardowski et al first developed the peritoneal equilibration test (PET) to characterize peritoneal transport rates [73]. There have been numerous reports to date on the use of PET in children [65,71,[74][75][76][77][78][79][80]. Warady et al addressed the lack of a standardized process and published pediatric reference data in 1996 from 95 children who underwent a standardized pediatric PET protocol [81].…”

Use of a modified peritoneal equilibration test to optimize solute and water clearance

“…4). It is interesting to note that in patients 2, 3, 5 and 6, there was little change in values from 120 min to 240 min, as would be anticipated from previous studies which demonstrate that children tend have more rapid equilibration of solutes [2][3][4]. Representation of mean values for the PETs are shown in Fig.…”

“…Depending upon the category into which an individual patient falls, the best dialytic modality for that patient may be selected [1, 2[. Recent data have also shown that the ratios obtained from the standard PET can be used to estimate clearance [4]. However, the D/P ratios that were used to calculate clearance in these patients were obtained at the 4-h time-point.…”

“…The PET is not useful in determining the prescription of dialysis that is required to achieve a desired clearance. Mendley et al [4] used a protocol similar to those listed above, except that the patient's previously prescribed volume was used. They were able to demonstrate that estimations of both Kt/V and weekly creatinine clearances obtained from PET data obtained at the "4-h" time-point correlated with measured Kt/V and creatinine clearances.…”

“…Urea clearance = D/Purea x Vdialysate (1) X cycles/week Total body water (based on surface area and age [4]. Statistical analysis.…”