title: Normalization of uremic acidosis in hemodialysis patients with a high bicarbonate dialysate.
abstract: Uremic acidosis accompanies chronic renal failure in hemodialysis patients because of a retention of nonvolatile acids. Standard bicarbonate (39 mEq/L) and acetate (38 mEq/L) dialysates do not completely correct the acidosis. The acid-base and biochemical effect of a high-bicarbonate (42 mEq/L) dialysate was evaluated in 38 patients during high-efficiency and high-flux dialysis over 12 wk. All patients were dialyzed on standard bicarbonate dialysate before the study and for 8 wk after the study. In order to monitor potential excessive alkalosis, predialysis and postdialysis arterial blood gases were measured in seven patients who initially had a normal predialysis pH. Serum chemistries revealed no significant changes in predialysis BUN, calcium, ionized calcium, or phosphorus during the 12-wk study. There was no change in postdialysis ionized calcium or phosphorus. Predialysis and postdialysis serum total CO2 (STCO2) increased over the 12-wk study (P < 0.0001). By week 12, 75% of the hemodialysis patients had an STCO2 > 23 mEq/L and no patient had an STCO2 > 30 mEq/L predialysis. After the 8-wk washout, all chemistries were no different from prestudy concentrations. Predialysis blood gases in seven patients with normal predialysis HCO3 revealed a significant increase (P < 0.009) in PCO2 and HCO3 over the 12-wk study; predialysis pH and PO2 did not change. There was no significant change in postdialysis blood gases. It was concluded that: (1) a high-bicarbonate dialysate corrects predialysis acidosis in 75% of hemodialysis patients without causing progressive alkalemia, hypoxia, or hypercarbia; and (2) predialysis BUN, calcium, ionized calcium, and phosphorus are unaffected by high-bicarbonate dialysate.
authors.affiliation: Emory University School of Medicine and Dialysis Clinic, Incorporated, Atlanta, GA 30308.
authors.forename: C W
authors.initials: CW
authors.lastname: Oettinger
authors.forename: J C
authors.initials: JC
authors.lastname: Oliver
mesh_terms: D000138:Acidosis / Q000097:blood / Q000188:drug therapy*; D001639:Bicarbonates / Q000627:therapeutic use*; D001774:Blood Chemical Analysis; D015314:Dialysis Solutions / Q000627:therapeutic use*; D005740:Gases / Q000097:blood; D006801:Humans; D012016:Reference Values; D006435:Renal Dialysis; D014511:Uremia / Q000097:blood / Q000188:drug therapy*
chemical_list: D001639:Bicarbonates; D015314:Dialysis Solutions; D005740:Gases