Follow-up study of peritoneal fluid kinetics in infants and children on peritoneal dialysis.

Objectives: To study longitudinal changes in transcapillary ultrafiltration (TCUF) and marker clearance (MC), as a reflection of lymphatic absorption, in children on peritoneal dialysis (PD). To present data on fluid kinetics in infants younger than 2.5 years, using an intraperitoneal volume of 1200 mL/m2 body surface area (BSA).

Design: The study involved a 4-hour dwell of 1200 mL/m2 BSA of dialysis fluid containing 3.86% glucose with Dextran 70 as volume marker. Cumulative TCUF and cumulative MC were measured.

Setting: A tertiary-care university hospital.

Patients: A follow-up period of 33 months of serial (1 - 4) peritoneal equilibration tests (PETs) was studied in 20 children with a median age of 6.4 years (range 2.1 - 15.4 years). Fluid kinetics in 5 additional infants with a median age of 1.4 years (range 0.5 - 2.5 years) was measured.

Results: Cumulative TCUF was 1041 mL/1.73 m2 at 1 - 3 months after start of PD, 1026 mL/1.73 m2 at 7 - 9 months, 1021 mL/1.73 m2 at 11 - 13 months, and 756 mL/1.73 m2 at 26 - 33 months (NS). Cumulative MC was 235 mL/1.73 m2 at 1 - 3 months after start of PD, 311 mL/1.73 m2 at 7 - 9 months, 395 mL/1.73 m2 at 11 - 13 months, and 509 mL/1.73 m2 at 26 - 33 months (NS). In infants, cumulative TCUF was 755 +/- 237 mL/1.73 m2; cumulative MC was 400 +/- 214 mL/1.73 m2.

Conclusions: Transcapillary ultrafiltration and marker clearance do not change in children > 2.5 years during the period studied. Fluid kinetics does not differ between infants < 2.5 years and older children when intraperitoneal volumes of 1200 mL/m2 BSA are used.