Dialytic sodium removal in children with acute kidney injury treated with peritoneal dialysis.

Background: Dialytic sodium removal (DSR) is an important parameter of peritoneal dialysis (PD) adequacy. The aim of this study was to report the DSR of children with acute kidney injury (AKI) on a standard acute PD prescription and to compare it to that of children on continuous flow peritoneal dialysis (CFPD).

Methods: A secondary analysis of prospectively collected data was performed from a published randomized controlled crossover trial comparing children on conventional PD and CFPD. The conventional PD prescription used: fill volume 20 mL/kg, glucose 2.5%, dwell time 45-60 min. In this study, we described and compared DSR in 15 children with AKI receiving PD and CFPD. Relative ultrafiltration through small pore (UFSP) was also described and compared.

Results: The median (range) weight and age of patients were 5.8 (2.3-14.0) kg and 6 (0.2-14) months. Approximately 8 h of dialysis was received per patient per modality. Results were then extrapolated and expressed per day. The mean ± SD DSR on conventional PD and CFPD were 2.7 ± 6 and 8.4 ± 10 mmol /kg/day, respectively (P = 0.02). The mean ± SD sodium dialysate to plasma (D/P) ratio on conventional PD and CFPD were 0.94 ± 0.03 and 0.94 ± 0.04 mmol/mmol (P = 1.0). Mean ± SD UFSP to total UF ratios on conventional PD and CFPD were 0.82 ± 0.39 and 0.66 ± 0.51 mL/mL (P = 0.14).

Conclusions: This study adds to the limited data on DSR in children on PD for AKI. CFPD removes more salt compared to conventional PD because of increased ultrafiltration (UF). A high percentage of UF was through small pores in both modalities.