Oxalate Clearance by High Flux Haemodialysis Using Polyacrylonitrile Membranes

Hyperoxalaemia is of importance because it may cause significant morbidity and mortality due to the tissue deposition of calcium oxalate crystals. It has been most extensively studied in the primary hyperoxalurias but oxalate retention and raised serum levels also occur late in renal failure and hyperoxalaemia is well documented in patients on treatment with haemodialysis and continuous ambulatory peritoneal dialysis (CAPD). There have been no studies however on the clearance of oxalate in patients treated with high flux dialysers. We therefore measured the clearance of oxalate in 6 patients on treatment with polyacrylonitrile dialysers (AN69HF). This was compared to the oxalate clearance in 5 patients on treatment with cuprophane dialysers, reported in a previous study (1).