A prospective randomised European multicentre study of medium-long run mortality and morbidity comparing acetate-free biofiltration and bicarbonate dialysis

In recent years, the progressive increase in the mean age of the population entering chronic dialysis treatment has been responsible, on the one hand, for the growing number of patients undergoing regular dialysis, and on the other, for the high number of "critical" patients, both as a result of the ir age and the presence of concomitant morbidity. Thus, dialysis treatment today is not only aimed at waste removal and waterelectrolyte homeostasis, but also at a reduction in morbidity and mortality, and at improving the pa tients' quality of life, thanks to the use of biocompatible materials and t he achievement of good cardiovascular tolerance to treatment. Consequently, diffusive-convective dialysis procedures have been on the increase, since they combine better depuration with the use of biocompatible high-flux memb ranes. Acetate-free biofiltration (AFB) is a diffusive-convective dialysis procedure which utilises a high-flux membrane, AN69, post-dilution infusion of a sodium bicarbonate solution (NaHCO3), and a dialysate which is comple tely free of any buffer, and thus also free of acetate, which may have vari ous negative effects on the patient. A number of studies have already shown the better hemodynamic stability and the reduction of intradialytic side-effects during AFB. All these, however , were short-term studies. To verify the beneficial effects of AFB in the long run, a three year multi centre randomised European trial has been proposed to compare bicarbonate h emodialysis (BD), a technique used in nearly 80% of the world's dialysis po pulation, and AFB. The specific aim of the investigation is to verify, in a large number of patients, the results of hemodialysis treatment iu terms o f morbidity; mortality and quality of life. The study involves 80 hemodialysis units across Italy, France, Germany, Spa in, Slovenia and Croatia, with enrolment of about 400 patients considered " critical" for at least one of the following reasons: age, diabetes, dialysi s cardiovascular instability. Fifty percent of the patients are to undergo AFB with the AN69 membrane and bicarbonate solution infusion (NaHCO3 145 or 167 mEq/lt), and the other fifty percent are to be treated by BD, with any membrane except the non-modified cellulosic one. Biochemical, cardiological, and nutritional parameters will be considered t hroughout the study. Mortality, morbidity both in terms of intra- and inter dialysis symptoms - and hospitalisation rate, as well as the patients' qual ity of life, evaluated by the SF36 questionnaire, will be analysed.