Efficacy and tolerance of acetate free biofiltration: a central Italian multicenter trial.

One hundred and thirteen patients from 51 dialysis units have been treated for 12 months on AFB using a high flux AN69 dialyzer (Filtral 12 or 16-Hospal), a buffer free dialysate (Na+ 139, K+ 2, Ca++ 2 mmol/liter, glucose 1 g/liter) and a reinfusate solution containing 145 mmol/liter HCO3Na. All of them had previously been stabilized on acetate dialysis (30 patients) or bicarbonate dialysis (46 patients) or different dialysis procedures (37 patients). AFB sessions were performed for 3.71 +/- 0.28 hrs, three times a week, at an average blood flow of 308 +/- 8.5 ml/min so as to ensure a stable Kt/V value > 1 (1.16 +/- 0.08). Blood samples were drawn monthly pre- and post-dialysis, for blood electrolytes, calcium, phosphate, chloride, urea, creatinine and uric acid, proteins and lipid profiles, hemochrome. Body weights, blood pressures and adverse side effects were recorded at each session. Using a mean infusion volume of 7.96 +/- 0.61 liter/session, post-dialytic bicarbonate values consistently > 25 mmol/liter (26.33 +/- 2.71) were achieved. Intradialytic occurrence of symptoms was very low at an average rate < 1.5 episodes patient/month. After 12 months of Tx an adequate control of uremia, of electrolytes, of Ca-PO4 balance and of BP was obtained. AFB gets a very high intradialytic tolerance and an excellent depurative capacity which contributes to the well being of the patients.