Figge 1998 Anion gap and hypoalbuminemia
Other studies relating anion gap to albumin
Studies comparing the performance of anion gap vs. albumin corrected anion gap
Why is there such a weak relationship between anion gap and albumin level?
A reminder to apply evidence-based medicine to acid-base physiology
- Current formulas that correct the anion gap for albumin are based on a publication by Figge 1998 which was flawed by circular logic.
- Clinical data sets relating anion gap to albumin have been unable to demonstrate a consistent or strong relationship between these variables.
- For detection of lactic acidosis, the uncorrected anion gap and the anion gap corrected for albumin have the same test performance.
- If the anion gap is corrected for albumin using conventional equations, the cutoff value must be increased by about 4 mM (compared to the cutoff value for the uncorrected anion gap).
- Figge 1998 has been cited over one hundred times and has been used to derive numerous models of acid-base physiology. These models may require revision.