#4452 ICODEXTRIN EFFICIENCY IN FLUID AND SODIUM REMOVAL REMAINS STABLE DURING LONG PERITONEAL DWELLS
Authors: Stachowska-Pietka Joanna , Waniewski Jacek , Olszowska Anna , Garcia-Lopez Elvia , Wankowicz Zofia , Lindholm Bengt 
Published: June 2023

Abstract

Background and Aims
Inadequate fluid and sodium removal has been shown to increase risk of overhydration and hypertension. In peritoneal dialysis, icodextrin-based solution provides sustained ultrafiltration, and therefore can be used for the long exchanges, especially in patients with fast solute transport rates in whom the effective ultrafiltration period is shortened. We investigated to which extent the efficiency of icodextrin in fluid and sodium removal is changing during 16-hour peritoneal dwells.

Method
Data on intraperitoneal volume, and concentrations of icodextrin and sodium in dialysate during 16 hours of peritoneal dwells with icodextrin-based solution were analysed in 11 clinically stable patients. Labeled serum albumin (RISA) was used as a volume marker and dialysate samples of 12 mL were collected at 8, 12, and 16 hours of peritoneal dwell. Residual volume was evaluated from marker dilution after 16 hours by rinsing peritoneal cavity with 2 L of fresh 1.36% glucose dialysis fluid. Ultrafiltration (UF) was calculated for each patient and each sampling time as the difference between drained and initially infused volume corrected for the sample volume. The total absorption of icodextrin-derived carbohydrates (AbsCHO) was calculated for each patient as the difference between initially infused and drained carbohydrates mass. The icodextrin ultrafiltration efficiency (UFE) was calculated for each sampling time as the ultrafiltration divided by the amount of icodextrin mass absorbed (AbsCHO). The efficiency of icodextrin in sodium removal (NaRE) was calculated for each sampling time as the sodium mass removed (difference between drained and initially infused sodium mass) divided by the corresponding icodextrin mass absorbed (AbsCHO). Correction for the residual volume and samples collections were applied for AbsCHO, UFE and NaRE calculations.

Results
After 16-hour dwell with icodextrin-based solution the ultrafiltration was positive in all except one patient, being on average (mean±SD) 669±369 mL. During the dwell, icodextrin was slowly absorbed from the peritoneal cavity, see Figure 1, left panel. At 16 hours, the mean cumulative CHO absorption (AbsCHO) reached 68.0±20.7 g (44±13% of initial CHO mass) while 56% of initial icodextrin mass infused still remained in dialysate, Figure 1, left panel. Icodextrin UF efficiency (UFE) calculated at 8, 12, and 16 hours remained stable (p = 0.6, ANOVA repeated measures) and was on average 9.9±5.8 mL/g, Figure 1, right panel. Moreover, icodextrin sodium removal efficiency (NaRE) also remained stable after 8 hours (p = 0.6, ANOVA repeated measures) and was on average 1.2±0.7 mmoL/g, Figure 1, right panel.

Conclusion
During 16 hours of peritoneal dialysis dwells with icodextrin-based solution, icodextrin was slowly absorbed with 56% of the osmotic agent remaining in the dialysate after 16 hours. The efficiency of icodextrin in terms of fluid (UFE) and sodium (NaRE) removal remained stable and did not subside from 8 to 16 hours of the dwell.