title: Patterns of metabolic acidosis in patients with chronic renal failure: impact of hemodialysis.
abstract: The type of metabolic acidosis in patients with chronic renal failure was studied prospectively over a three-month period in 32 stable patients on chronic hemodialysis using acetate. All patients had pre-dialysis metabolic acidosis (mean TCO2 = 16.6 +/- 0.4 mEq/l, range 10 to 23 mEq/l). The patterns of metabolic acidosis were defined using the ratio: delta AG/delta TCO2 where delta AG is the increment in plasma anion gap above normal and delta TCO2 the decrement in plasma bicarbonate below normal. The group as a whole showed a mixed hyperchloremic and high anion gap pattern with a mean delta AG/delta TCO2 ratio of 53.3 +/- 7.1%. The individual distribution of patterns ranged from a pure hyperchloremic acidosis (24%) to a pure high anion gap acidosis (30%) with the mixed pattern being the most frequent (46%). An inverse correlation between the TCO2 change (y) during the dialysis procedure and the TCO2 (x) prevailing at the start of dialysis was found by linear regression analysis: y = -0.51x + 11, r = -0.54, p less than 0.01. Thus, before acetate conversion to bicarbonate was fully completed, patients gained bicarbonate during dialysis if TCO2 was less than 21 mEq/l and lost it when the pre-dialysis TCO2 was above this level. On average, the delta AG was reduced to a greater extent than the delta TCO2 so that the delta AG/delta TCO2 ratio fell significantly (from 53 +/- 7.1 to 11 +/- 8.8%, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Northwestern University Medical School, Chicago.
authors.forename: E
authors.initials: E
authors.lastname: Cohen
authors.forename: K
authors.initials: K
authors.lastname: Liu
authors.forename: D C
authors.initials: DC
authors.lastname: Batlle
mesh_terms: D000136:Acid-Base Equilibrium; D000138:Acidosis / Q000209:etiology* / Q000378:metabolism; D000328:Adult; D000368:Aged; D001806:Blood Urea Nitrogen; D003404:Creatinine / Q000378:metabolism; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000378:metabolism* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000378:metabolism; D011446:Prospective Studies; D006435:Renal Dialysis
chemical_list: D003404:Creatinine; D011188:Potassium