UMEM Educational Pearls

Category: Critical Care

Title: Anion Gap in DKA

Posted: 6/13/2012 by Mike Winters, MBA, MD (Updated: 6/17/2024)
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Use the Measured Sodium Concentration!

  • During a recent shift, a question arose regarding whether to use the measured or corrected sodium to calculate the anion gap in a critically ill patient with DKA.
  • Recall that the anion gap provides an estimation of unmeasured anions - in this case acetoacetate and beta-hydroxybutyrate.
  • Glucose is electrically neutral and therefore does not affect the anion gap.
  • When calculating the anion gap in a patient with DKA, use the actual (measured) serum Na, rather than the corrected value.


Beck, L. Cleveland Clin J Med 2001;68:673.