[Dialysis dose, nutrition and growth among pediatric patients on peritoneal dialysis].

BACKGROUND Stunting is common among pediatric patients on peritoneal dialysis. AIM To establish the best profile for urea kinetic variables associated to growth in children on chronic peritoneal dialysis (PD). PATIENTS AND METHODS Twenty patients, aged 1 month to 14 years, 13 males, were followed for 6-12 months, with monthly measurements of weight/age and height/age Z score; plasma creatinine, BUN, protein and albumin and urine and dialysate urea nitrogen, creatinine, protein and albumin. Minimum total Kt/V was 2.1. Dialysis dose (Kt/V), Protein Equivalent of Urea Nitrogen Appearance (PNA), Protein Catabolic Rate (PCR) and Nitrogen Balance (NB) were calculated. To identify the variable(s) associated to growth, the Tree Classification Model (CART) Enterprise Miner 8.1 was applied. RESULTS Mean total/residual Kt/V: 3.4+/-1.3/1.69+/-1.27; Daily Protein Intake (DPI) was 3.25+/-1.27 g/kg/day. nPNA, PCR and NB were 1.37+/-0.44, 0.84+/-0.33 and 1.86+/-1.25 g/kg/day, respectively. Mean height/age Z score was -2.3+/-1.19. Eleven patients showed a positive height/age delta Z (mean 0.55+/-0.38) and nine showed a negative growth (mean -0.50+/-0.42). The main variable explaining the positive growth was a Nitrogen Balance between 0.54 and 2.37 g/kg/day, mean 1.55+/-0.21 (p <0.001). The second associated variable to growth was a residual Kt/V between 0.43 and 4.6 (2.02+/-0.49) (p <0.05). Kt/V and nPNA showed a significant correlation, but no correlation could be found between Kt/V and NB. CONCLUSIONS Nitrogen Balance was the main variable associated to growth in pediatric PD, with values between 0.53 to 2.38 g/kg/day. The second variable was a residual Kt/V between 0.43 and 4.6. Therapy should be reassessed with NB values less than 0.54 or above 2.37 g/kg/day.