557 - Longitudinal Trajectories of Dialytic Clearance and Residual Kidney Function in Pediatric Patients Initiating Peritoneal Dialysis

Publication Number: 4545.557

Mahima Keswani, Ann and Robert H. Lurie Childrens Hospital of Chicago; Northwestern Medicine, Chicago, IL, United States; Annabelle Chua, Duke, Hillsborough, NC, United States; Eric D. Weinhandl, University of Minnesota Medical School, Victoria, MN, United States; Emma L. Dougherty, DaVita, Peachtree Corners, GA, United States; Melisha Hanna, University of Colorado School of Medicine, Aurora, CO, United States; Mihran V. Naljayan, Louisiana State University School of Medicine in New Orleans, Brookhaven, MS, United States; Isidro B.. Salusky, University of California, Los Angeles David Geffen School of Medicine, Los Angeles, CA, United States

Background: The impact of residual urea clearance (RUC) on total weekly clearance in pediatric end-stage kidney disease (ESKD) patients who initiate treatment with peritoneal dialysis (PD) is unknown.

Objective: To assess the longitudinal change of RUC and dialytic Kt/V in pediatric patients who initiated PD within DaVita Kidney Care (DKC), a national network of dialysis facilities utilizing a standardized protocol.

Design/Methods: We analyzed data from patients aged >1 year to < 18 years who initiated PD in a DKC facility between January 1, 2011, and December 31, 2024. Inclusion criteria comprised measurement of RUC within 90 days and continuation of PD therapy for at least 6 months. Patients were followed for up to 3 years after initiation of PD, or until the earliest of death, kidney transplantation, or transfer out of DKC facilities. Blood, dialysate effluent, and 24-hour urine samples were collected quarterly, and delivered to a central laboratory for measurement of urea concentrations and estimation of dialytic, residual, and total Kt/V. We used mixed models, adjusted for age and sex, to estimate mean trajectories of total, dialytic, and residual Kt/V, as well as within-patient trajectories of residual Kt/V.

Results: The cohort included 223 patients in 60 facilities. Mean age was 13.8 (standard deviation [SD], 3.7) years; 60% of patients were male. During follow-up, the cumulative incidence of kidney transplantation was 22% at 1 year, 56% at 2 years, and 65% at 3 years; the cumulative incidence of death and transfer out of DKC facilities was 1% and 14%, respectively, at 3 years. At baseline, mean total, dialytic, and residual Kt/V was 2.81 (SD, 1.24), 1.45 (0.47), and 1.36 (1.21), respectively, indicating highly variable RKF; at 3 years, corresponding means were 2.36 (SD, 0.80), 1.91 (0.44), and 0.45 (0.85) (Figure 1). During follow-up, mean adjusted slopes of total, dialytic, and residual Kt/V were -0.05 (test of zero slope, P < 0.0001), +0.04 (P < 0.0001), and -0.10 (P < 0.0001) per quarter, commensurate with gradual loss of RKF and concurrent increase in dialytic clearance. During the first year of PD, the estimated slope of residual Kt/V was less than -0.20 per quarter in 22% of patients, indicating relatively rapid loss of RKF (Figure 2).

Conclusion(s): Pediatric patients undergoing PD achieved adequate therapy through contributions of both RUC and dialytic clearance. As time elapsed, although total Kt/V remained adequate, RUC gradually declined, shifting clearance predominantly to PD. The impact of such changes on specific outcomes, such as growth and nutritional status, remains to be studied.

Mean Total, Dialytic, and Residual Kt/V, by Follow-up Quarter


Estimated trajectory of residual Kt/V during the first year of PD
Patients with rapid loss of RUC are displayed with solid orange lines; all others patients are displayed with dotted gray lines.