The Influences of Dialysate Bicarbonate Concentrations on Hemodialysis Patients

Background: Patients with decreased kidney function are in the positive acid balance due to insufficient renal acid excretion. To correct the varying degrees of metabolic acidosis in these HD patients, a high concentration of HCO3 in the dialysate is routinely used. During every 3-to-4 hours of HD treatment, a massive surge of HCO3 would enter the circulation and typically overcorrects predialysis acidosis to alkalosis and alkalemia. The sharp acid-base shift can cause some adverse consequences. The investigators believe that the rapid correction (or overcorrection) from the pre-dialysis metabolic acidosis to post-dialysis metabolic alkalosis during the 3-to-4 hours HD treatment would relate to adverse effects on HD patients. Thus the investigators conduct this study to prove the hypothesis that "prevention of post-dialysis alkalosis by using lower dialysate HCO3 concentration might cause less adverse outcomes in ESRD patients on HD." Study design: Prospective cross-over case-control study. Study population: A total of 60 patients who receive regular hemodialysis (three times per week) for more than 6 months in the regional teaching hospital.