A New Method to Increase Ultrafiltration in Peritoneal Dialysis: Steady Concentration Peritoneal Dialysis

Background Peritoneal dialysis (PD) has limited power for liquid extraction (ultrafiltration), so fluid overload remains a major cause of treatment failure.Methods We present steady concentration peritonal dialysis (SCPD), which increases ultrafiltration of PD exchanges by maintaining a constant peritoneal glucose concentration. This is achieved by infusing 50% glucose solution at a constant rate (typically 40 mL/h) during the 4-hour dwell of a 2-L 1.36% glucose exchange. We treated 21 fluid overload episodes on 6 PD patients with high or average-high peritoneal transport characteristics who refused hemodialysis as an alternative. Each treatment consisted of a single session with 1 to 4 SCPD exchanges (as needed).Results Ultrafiltration averaged 653 ± 363 mL/4 h — twice the ultrafiltration of the peritoneal equilibration test (PET) (300 ± 251 mL/4 h, p < 0.001) and 6-fold the daily ultrafiltration (100 ± 123 mL/4 h, p < 0.001). Serum and peritoneal glucose stability and dialysis efficacy were excellent (glycemia 126 ± 25 mg/dL, peritoneal glucose 1,830 ± 365 mg/dL, D/P creatinine 0.77 ± 0.08). The treatment reversed all episodes of fluid overload, avoiding transfer to hemodialysis. Ultrafiltration was proportional to fluid overload ( p < 0.01) and inversely proportional to final peritoneal glucose concentration ( p < 0.05).Conclusion This preliminary clinical experience confirms the potential of SCPD to safely and effectively increase ultrafiltration of PD exchanges. It also shows peritoneal transport in a new dynamic context, enhancing the influence of factors unrelated to the osmotic gradient.