Bimodal solutions in peritoneal dialysis: what can we expect from different glucose volumes added to the icodextrin...

Ultrafiltration (UF) insufficiency in peritoneal dialysis (PD) often leads to transfer to hemodialysis. Therefore, strategies to prolong time on therapy are needed. The use of a combined crystalloid and colloid solution, also called bimodal PD, can help improve UF.

We propose a method for reconstituting bimodal solutions. Three bimodal PD solutions, with respectively 100 ml (solution 100), 150 ml (solution 150) and 200 ml (solution 200) of 30% glucose for intravenous (IV) infusion, were prepared to explore whether a variation of the amount of glucose can be useful to adapt the PD prescription. Biochemical analyses and computer simulations (based on the 3-pore model) were carried out on these solutions to assess their Na and UF efficiency. Data on the clinical use of solution 200 were retrospectively collected.

The addition of 30% glucose to the icodextrin 7.5% bag resulted in a low-sodium solution. After a 6-h dwell with the solution 200, in a high-average transporter patient with a Dialysate over Plasma (D/P) creatinine at 0.7, the theoretical volume of ultrafiltration was 943.0 ml and the amount of sodium removed was 8.29 g compared to 650.3 ml and 6.14 g with solution 100. When considering the glucose absorption during the dwell, solution 100 was associated with the best ultrafiltration efficiency, defined as the volume of UF obtained divided by the amount of free glucose absorbed, and the best sodium efficiency, defined as the mass of sodium removed divided by the amount of free glucose absorbed during the dwell. Four patients used bimodal solution 200 for at least 2 months between 2018 and 2023 and were included in the retrospective study on clinical use. Mean time spent on PD before bimodal PD first prescription was 26 months (6-38 months). Median time spent using a bimodal PD regimen was 15 months (12-19 months). No episodes of peritonitis were reported while using this strategy.

Our study describes a simple method to prepare a bimodal solution. Biochemical and computer study of 3 solutions suggested that using 100 ml of 30% glucose to 2 L of icodextrin 7.5% gives the best UF and Na efficiency.