The influence of dialysis fluid composition on dialysis tolerance.

To evaluate the role of bicarbonate loss through the dialyser and acetate flux to the patient in the development of symptoms during acetate dialysis, bicarbonate loss during acetate dialysis was prevented by using a combination of acetate and bicarbonate in the dialysate. Seven uraemic patients were treated for 4 months with acetate dialysis and, successively, for a similar period of time with bicarbonate, and a combination of acetate and bicarbonate dialysis. Blood-pressure drop and the incidence of hypotension and symptomatic episodes were similar in bicarbonate and combination dialysis, and significantly lower than in acetate dialysis. Serum acetate concentrations were similar during acetate and combination dialysis. These findings indicate that bicarbonate loss rather than the presence of acetate was responsible for the patients' intolerance to acetate dialysis.