Phosphate clearance in peritoneal dialysis

Malgorzata Debowska,Joyce Pinto,Jacek Waniewski,Bengt Lindholm,Rafael Gomez

doi:10.1038/s41598-020-74412-2

Abstract

In renal failure, hyperphosphatemia is common and correlates with increased mortality making phosphate removal a key priority for dialysis therapy. We investigated phosphate clearance, removal and serum level, and factors associated with phosphate control in patients undergoing continuous ambulatory (CAPD), continuous cyclic (CCPD) and automated (APD) peritoneal dialysis (PD). In 154 prevalent PD patients (mean age 53.2 ± 17.6 year, 59% men, 47% anuric), 196 daily collections of urine and 368 collections of dialysate were evaluated in terms of renal, peritoneal and total (renal plus peritoneal) phosphorus removal (g/week), phosphate and creatinine clearances (L/week) and urea KT/V. Dialytic removal of phosphorus was lower in APD (1.34 ± 0.62 g/week) than in CAPD (1.89 ± 0.73 g/week) and CCPD (1.91 ± 0.63 g/week) patients; concomitantly, serum phosphorus was higher in APD than in CAPD (5.55 ± 1.61 vs. 4.84 ± 1.23 mg/dL; p < 0.05). Peritoneal and total phosphate clearances correlated with peritoneal (rho = 0.93) and total (rho = 0.85) creatinine clearances (p < 0.001) but less with peritoneal and total urea KT/V (rho = 0.60 and rho = 0.65, respectively, p < 0.001). Phosphate removal, clearance and serum levels differed between PD modalities. CAPD was associated with higher peritoneal removal and lower serum level of phosphate than APD.

Highlights

In renal failure, hyperphosphatemia is common and correlates with increased mortality making phosphate removal a key priority for dialysis therapy
We investigated associations of weekly renal, peritoneal and total phosphate clearance, removal and serum phosphorus concentration with different parameters of dialysis and patient characteristics in patients treated by continuous ambulatory (CAPD), continuous cyclic (CCPD) and automated (APD) peritoneal dialysis (PD)
In the investigated therapies (CAPD, CCPD and APD), peritoneal transport types were distributed with 17–19%, 30–38%, 32–44% and 5–17% measurements belonging to slow, slow-average, fast-average and fast transport types, respectively (Table 1)

Summary

Introduction

Hyperphosphatemia is common and correlates with increased mortality making phosphate removal a key priority for dialysis therapy. The dialytic removal of phosphorus combined with use of phosphate binders are usually inadequate to counteract the intestinal absorption of phosphorus in patients with renal failure. The dialytic removal of phosphorus combined with use of phosphate binders are usually inadequate to counteract the intestinal absorption of phosphorus in patients with renal failure2 This leads to hyperphosphatemia and secondary hyperparathyroidism, which are associated with adverse cardiovascular outcomes and contribute to increased risk of death. We investigated associations of weekly renal, peritoneal and total (renal plus peritoneal) phosphate clearance, removal and serum phosphorus concentration with different parameters of dialysis and patient characteristics in patients treated by continuous ambulatory (CAPD), continuous cyclic (CCPD) and automated (APD) peritoneal dialysis (PD)

Methods

Results

Conclusion