Clearances and solutes extraction in biofiltration and hemodialysis with the AN 69 S

Clearances and solutes extraction were assessed in biofiltration (BF) and in hemodialysis (HD) with the new polyacrylonitrile AN 69 S membrane. Three patients treated for three months by acetate dialysis (4 hours X 3) and subsequently by BF (3 hours X 3) were studied after achievement of steady state. Total intradepurative clearances (diffusive and convective) and solutes extraction of urea, creatinine, uric acid and phosphate were determined. Clearance of small molecular weight solutes was better in BF than in HD especially for uric acid and phosphate. This confirms the high depurative efficiency of the AN 69 S. BF gave better total clearances than HD, but the extraction of lower molecular weight solutes (due to the one-hour reduction of dialysis time) suggests that adequate treatment time is needed with this technique.