FP448A MINIATURE ARTIFICIAL KIDNEY FOR PERITONEAL DIALYSIS - WEAKID

Abstract

Introduction and Aims: We have developed a miniature artificial kidney (WEAKID-H2020 SC1) for peritoneal dialysis (PD), that recirculates the peritoneal dialysate via a tidal mode using a single lumen peritoneal catheter. The dialysate is continuously regenerated by the system containing sorbents, maintaining a large plasma-dialysate concentration gradient, thereby enhancing blood purification while reducing the number of exchanges. Application is envisaged at night as a bedside device (nighttime system). Optionally, a wearable system (~1.5 kg) can provide additional clearance during the day. The removal of potassium, phosphate, urea and creatinine removal from spent peritoneal dialysate was studied. Methods: The night-and daytime WEAKID systems were tested separately (n=3 per system). In each system, 2 L of spent peritoneal dialysate was continuously recircu-lated via a tidal mode (mean flow rate: 100 and 50 ml/min, respectively) in a closed-loop system over a sorbent cartridge for 8 h. To simulate the in vivo situation, potassium, phosphate, urea and creatinine were added to the peritoneal effluent each hour. Samples were taken hourly. Cumulative removal was quantified during the 8 h experiment. Modeling was used to estimate cumulative removal during 24 h and time aver-aged plasma clearances applying one Extraneal exchange per day (Table 1). Both systems were equilibrated at physiological calcium and magnesium concentrations, hypotonic sodium concentration, and lactate concentration of 35 mM. Results: Cumulative removal of potassium, phosphate, urea and creatinine by the nighttime system was 26 6 5,11 62.7, 206 629 and 1062.4mmolin 8h, and by the daytime system 060, 6.5 61.7, 35 64.4, 5.3 60.5 mmolin 8 h, respectively, at peritoneal dialysate [K+] of 3.7 60.5 mM, [PO43-] 1.3 60.5 mM, [urea] 21 65.1 mM and [creatinine] 0.660.2 mM (Table 1). Equilibration of the night-and daytime system could prevent calcium and magnesium removal and sodium release. Cumulative glucose release by the nighttime system was 79623 mmol in 8 h. Cumulative lactate release with the night-and daytime system was 5463.9 and 33615 mmol, respectively.Table 1. Daily cumulative removal and plasma clearance based on modeling [Figure Presented] Conclusions: Clinically relevant removal of potassium, phosphate, urea and creati-nine from peritoneal dialysate by a miniature artificial kidney for peritoneal dialysis, was shown in vitro. Time-averaged plasma clearances of phosphate, urea and creatinine based on modeling suggest superior performance compared to conventional PD. The evaluation of the WEAKID system in a uremic large animal model is warranted to study uremic toxin removal, glucose release, and influence on electrolyte and acid-base balance in vivo.