Acetate-free biofiltration (AFB) is an HDF technique performed with a base-free dialysate and a simultaneous continuous post-dilution infusion of a sterile isotonic bicarbonate solution. In AFB, the transmembrane pressure is such that no backfiltration occurs and the quality of dialysate water need not to be as rigorously controlled as in HDF
A more personalized prescription for buffer replenishment can be provided with acetate-free biofiltration technique, where the plasma bicarbonate to be reached at the end of a session and the amount of bicarbonate to be infused in order to obtain that concentration can be calculated with a reliable mathematical formula that takes into account readily available clinical and technical data