Serum Electrolyte and Acid Base Composition

Abstract

Data from 41 ambulatory patients with graded degrees of uncomplicated, chronic renal failure were used to define the quantitative relationship between serum acid-base and electrolyte composition and the serum creatinine level. Even in patients with only moderate renal insufficiency, serum total carbon dioxide (tCO₂) content was reduced significantly. This early fall in tCO₂ was offset by an increase in serum chloride (Cl-), serum undetermined anion concentration (A-) remaining normal. In patients with more severe degrees of renal insufficiency, further decrements in tCO₂ occurred that were proportional to the increment in serum creatinine. These latter decrements in tCO₂ were associated with equivalent increments in A-, serum Cl-- remaining unchanged at the elevated level observed during moderate renal insufficiency. Confidence limits of 95% for tCO₂ and A were calculated from the data. (Arch Intern Med 139:1099-1102, 1979)