Factors related to ultrafiltration volume with icodextrin dialysate use in children

BACKGROUND

Icodextrin has a lower absorption rate, and icodextrin peritoneal dialysate contributes to more water removal than glucose dialysate in patients with high peritoneal permeability. There are limited data on icodextrin dialysate use in children.

METHODS

This study included all pediatric patients who received peritoneal equilibration tests and peritoneal dialysis with icodextrin dialysate at the study center. The factors related to ultrafiltration volume with icodextrin dialysate with long dwell time were statistically analyzed. Then the ultrafiltration volume with icodextrin and medium-concentration glucose dialysate was compared in individual cycles in the same patients.

RESULTS

Thirty-six samples were included in the icodextrin group, and nine samples were used to compare the ultrafiltration volume with icodextrin and glucose dialysate. Dwell time, D/P-creatinine, D/D₀-glucose, age, height, and weight correlated significantly with the ultrafiltration volume of icodextrin dialysate (p < 0.05). A dwell volume equal to or more than 550 mL/m² was associated with a significantly higher ultrafiltration volume than a lower dwell volume (p = 0.039). Multiple regression analysis revealed that dwell time (p = 0.038) and height (p < 0.01) correlated with ultrafiltration volume significantly. In addition, the ultrafiltration volume was superior (p < 0.01), and dwell time was longer (p = 0.02), with icodextrin dialysate than with medium-concentration glucose dialysate.

CONCLUSIONS

The ultrafiltration volume with icodextrin dialysate decreases in patients with small stature. Providing sufficient dwell time and volume is important for maximal water removal even in children. Ultrafiltration volume is superior with icodextrin than medium-concentration glucose dialysate for long dwell times. A higher resolution version of the Graphical abstract is available as Supplementary information.

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

Objectives

Differences in peritoneal fluid handling in the acute setting can be expected if children are converted to pH-neutral dialysis solutions because conventional acidic solutions exert toxic effects on peritoneal mesothelial cells and microcirculation. Peritoneal fluid kinetics was therefore investigated with both types of solutions in a group of children.

Design

Peritoneal equilibration tests (PETs) were performed in 12 patients [mean age 70 months, mean time on peritoneal dialysis (PD) 18 months] using a pH-neutral PD fluid (Physioneal 3.86%; Baxter Ltd, Castlebar, Ireland) and dextran 70 as a volume marker. The results of these PETs were compared to those of a historic group of 12 children (mean age 75 months, mean time on PD 17 months).

Setting

Pediatric dialysis unit in a tertiary institute.

Patients

Stable pediatric PD patients.

Main Outcome Measures

Transcapillary ultrafiltration (TCUF) and marker clearance, dialysate-to-plasma (D/P) ratios for urea and creatinine, and Dt/D0ratio for glucose.

Results

TCUF and lymphatic absorption were not different between the two groups. There was also no significant difference in small solute clearance measured by D/P ratio for urea and creatinine and Dt/D0ratio for glucose.

Conclusion

Peritoneal fluid kinetics is not significantly altered if pH-neutral dialysis solutions are applied compared to acidic solutions. An altered TCUF, as is hypothetically possible using an acidic solution, was not established.

Quantitative Histomorphometry of the Healthy Peritoneum

The peritoneum plays an essential role in preventing abdominal frictions and adhesions and can be utilized as a dialysis membrane. Its physiological ultrastructure, however, has not yet been studied systematically. 106 standardized peritoneal and 69 omental specimens were obtained from 107 patients (0.1–60 years) undergoing surgery for disease not affecting the peritoneum for automated quantitative histomorphometry and immunohistochemistry. The mesothelial cell layer morphology and protein expression pattern is similar across all age groups. Infants below one year have a thinner submesothelium; inflammation, profibrotic activity and mesothelial cell translocation is largely absent in all age groups. Peritoneal blood capillaries, lymphatics and nerve fibers locate in three distinct submesothelial layers. Blood vessel density and endothelial surface area follow a U-shaped curve with highest values in infants below one year and lowest values in children aged 7–12 years. Lymphatic vessel density is much lower, and again highest in infants. Omental blood capillary density correlates with parietal peritoneal findings, whereas only few lymphatic vessels are present. The healthy peritoneum exhibits major thus far unknown particularities, pertaining to functionally relevant structures, and subject to substantial changes with age. The reference ranges established here provide a framework for future histomorphometric analyses and peritoneal transport modeling approaches.

Acute peritoneal dialysis in very low birth weight neonates using a vascular catheter

We report on our experience with acute peritoneal dialysis (APD) in 16 very low birth weight neonates ranging from 24.6 to 30.2 weeks' gestation with a birth weight ranging from 630 g to 1,430 g using a 14-gauge Arrow vascular catheter for APD access. The underlying causes of acute renal failure were: sepsis (7), necrotizing enterocolitis (4), patent ductus arteriosus (3), hydrops fetalis (1), intracranial hemorrhage (3), pulmonary hemorrhage (2), pneumonia (1), and perinatal asphyxia (1). Among 12 patients, the APD was successful for the control of hyperkalemia, fluid overload, and metabolic acidosis. The peritoneal permeability and transport were at their maximum at a short dwell time with rapid exchanges. Complications associated with the APD were: peritonitis (2), leakage (2), hemoperitoneum (1), and hernia (1). During the dialysis, four patients died; there were three episodes of catheter-related complications in these patients. At 60 days after the withdrawal of the APD, 10 patients were alive, and had full recovery of their renal function. Therefore, APD in premature neonates with a 14-gauge Arrow vascular catheter was safe and effective. This procedure helped manage the hemodynamic and metabolic imbalance of acute renal failure and was associated with few complications.