Clinical status and acid-base balance during biofiltration in patients with acetate dialysis intolerance

Nine patients intolerant to acetate hemodialysis were treated with biofiltration. This consisted in a 4-h acetate hemodialysis during which an additional 2 liters of ultrafiltrate were replaced by a bicarbonate solution (100 mEq/l). Hypotensive episodes disappeared and six out of nine patients were symptom-free during the session. Compared to standard hemodialysis, arterial blood bicarbonate and pO2 did not drop during biofiltration. The anion gap did not change during standard hemodialysis, but was significantly reduced during biofiltration (24.5 +/- 2.9 vs 19.9 +/- 1.4 mEq/l). In our conditions clinical results were positive with biofiltration. On the basis of anion gap changes and preliminary results of plasma acetate determinations, it is suggested that a better cellular metabolism of acetate may be induced by bicarbonate infusion.