Plasma acid-base changes in chronic renal failure: A Stewart analysis

D. A. Story, A. Tosolini, Rinaldo Bellomo, M. Leblanc, L. Bragantini, C. Ronco

Research output: Contribution to journalArticleResearchpeer-review

20 Citations (Scopus)


The bicarbonate centered approach to acid-base physiology involves complex explanations for the metabolic acidosis associated with chronic renal failure. We used the alternate Stewart approach to acid-base physiology to quantify the acid-base chemistry of patients with chronic renal failure. We examined the plasma and urine chemistry of 19 patients with chronic renal failure who were predialysis and 20 healthy volunteers. We compared the plasma strong-ion-difference due to sodium, potassium, and chloride ions as well as the weak acids albumin and phosphate. We used a simplified Fencl-Stewart approach to quantify the effects of sodium-chloride, albumin, and unmeasured ions on base-excess. The chronic renal failure group had a greater metabolic acidosis, with a base-excess that differed from the healthy group by a mean of -2.7 mmol/L, p= 0.04. This was associated with a strong ion acidosis due to both increased chloride and decreased sodium. The anion gap, strong-ion-gap, and base-excess effect of unmeasured ions were similar in both groups suggesting that unmeasured ions had only a minor role in the acid-base status in this group of patients.

Original languageEnglish
Pages (from-to)961-965
Number of pages5
JournalInternational Journal of Artificial Organs
Issue number10
Publication statusPublished - 1 Oct 2005
Externally publishedYes


  • Acid-base
  • Chloride
  • Phosphate
  • Renal failure
  • Sodium
  • Strong ion difference

Cite this