Phosphate elimination in modalities of hemodialysis and peritoneal dialysis

Abstract

Hyperphosphatemia is highly prevalent in hemodialysis (HD) and peritoneal dialysis (PD) patients and is a major risk factor for cardiovascular mortality. Elimination of inorganic phosphate by dialysis is a cornerstone of the management of hyperphosphatemia. Phosphate clearance during HD is affected by various factors of dialysis prescription, such as blood and dialysate flow rate, dialyzer membrane surface area and ultrafiltration volume. Phosphate mass removal can be improved by hemodiafiltration, increased dialysis frequencies and extended treatment times. Short daily or extended daily or 3 times weekly nocturnal HD allow higher phosphate mass removal and potentially complete discontinuation of phosphate binder medication. In PD, phosphate mass removal appears to be correlated with peritoneal creatinine but not urea clearance. In hyperphosphatemic PD patients, the decision on the optimal PD modality should be based on peritoneal creatinine and ideally also on peritoneal phosphate transport characteristics.