Follow-Up Study of Peritoneal Fluid Kinetics in Infants and Children on Peritoneal Dialysis

Abstract

Objectives To study longitudinal changes in trans-capillary 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.

Quantitative Histomorphometry of the Healthy Peritoneum

“…While water is reabsorbed along the Starling forces into the blood capillaries, larger molecules are mainly reabsorbed via lymphatic vessels. Based on dextran uptake, the lymphatic absorption rate has been estimated to be 1.5–2 ml/min/1.73 m 2 in children aged 1–18 years, with 70% higher rates measured in infants younger than two years of age 20 21 . Lower ultrafiltration rates are achieved with icodextrin fluid in infants than in older children, possibly due to higher icodextrin absorption 22 .…”

No Significant Differences in Peritoneal Fluid Handling in Children Using pH-Neutral or Acidic Solutions

“…Our patients, however, were matched for time on PD and analyzed as matched pairs, thereby reducing the difference in chronic changes in the peritoneal membrane between the two groups. Also, previous authors have shown no difference in small solute transport creatinine clearance or TCUF in children on chronic PD up to 33 -55 months (23)(24)(25). As the longest time on PD was 52 months, it is unlikely that any long-term effects on the peritoneal membrane had yet taken place.…”