MO683: Peritoneal Transport Characteristics, Sodium Sieving and Dialysate Electrolyte Clearance in Peritoneal Dialysis Patients: 4.25% Peritoneal Equilibration Test Analysis

Abstract

Abstract BACKGROUND AND AIMS Peritoneal dialysis (PD) is a well-established renal replacement therapy for patients with end-stage renal disease. The peritoneal equilibration test (PET) is widely used for assessing peritoneal solute transport. Recently, the International Society for PD committee recommended performing PET with 4.25% dextrose solution instead of traditional 2.5% dextrose solution to provide better information on ultrafiltration capacity. This study aims to explore the peritoneal transport characteristics, sodium sieving and electrolyte clearance with PET-4.25%. METHOD We conducted a cross-sectional study in PD patients treated in West China Hospital between June 2021 and December 2021. All patients underwent PET-4.25%. Peritoneal transport characteristics, sodium sieving and dialysate electrolyte clearance were analysed. RESULTS A total of 108 patients (61 males, 56%; mean age 48 ± 4 years old, median PD duration 17 months) were included. Dialysate to plasma (D/P) creatinine values at 4 h were distributed similarly in PET-2.5% and PET-4.25% (Fig. 1). The dialysate sodium decreased at the beginning of PET-4.25% and gradually increased, while other dialysate electrolyte levels continued to increase or decrease during the 4 h (Fig. 2). Most patients had their maximal sodium dip at 2 h (N = 80, 74%). The mean sodium dip at 1 h was 7.28 ± 2.93 mmol/L (sodium sieving ratio 0.057 ± 0.023), and the mean maximal sodium dip was 8.81 ± 4.18 mmol/L. In both univariate and multivariate analyses, sodium sieving was negatively correlated with 4-h D/P creatinine and glomerular filtration rate (GFR) and positively correlated with PET-4.25% ultrafiltration volume (Fig. 3). The total clearances of sodium, potassium, chloride, calcium, magnesium and phosphate with 2 L of 4.25% dextrose were 66.9 ± 22.4 mmol, 6.64 ± 1.25 mmol, 62.7 ± 27.7 mmol, 0.07 ± 0.27 mmol, 0.63 ± 0.19 mmol and 1.98 ± 0.63 mmol, respectively. The amount of electrolyte clearance was not related to peritoneal transport characteristics. Nine patients were diagnosed with ultrafiltration failure (UFF). Patients with UFF had significantly lower sodium and chloride clearance than non-UFF patients. CONCLUSION PET-4.25% could assess peritoneal transport characteristics with similar results to PET-2.5%, while it could provide more information on ultrafiltration capacity. Four-hour D/P creatinine, GFR and ultrafiltration volume are independent predictors for sodium sieving. Dialysate electrolyte clearance is not related to peritoneal transport characteristics, while sodium clearance is decreased in UFF patients.