Bedside Rounds

Sodium corrected for glucose

High glucose draws water out of cells and dilutes sodium. The corrected sodium shows the true sodium status, which guides fluid choice in DKA and HHS.

What goes into the Sodium corrected for glucose

  • Measured sodium (mEq/L)
  • Glucose (mg/dL)

How to interpret the result

  • Hillier: add 2.4 mEq/L for every 100 mg/dL of glucose above 100 (more accurate at high glucose)
  • Katz: add 1.6 mEq/L for every 100 mg/dL above 100
  • A normal or high corrected sodium means significant free water loss

Clinical pearls

  • After initial resuscitation in DKA and HHS, corrected sodium guides the choice between 0.9% and 0.45% saline.
  • Expect measured sodium to rise as glucose falls; a falling corrected sodium suggests too much free water.

Evidence

  1. Katz MA. Hyperglycemia-induced hyponatremia: calculation of expected serum sodium depression. N Engl J Med. 1973;289:843-844.
  2. Hillier TA, Abbott RD, Barrett EJ. Hyponatremia: evaluating the correction factor for hyperglycemia. Am J Med. 1999;106:399-403.

Related workups

Diabetic ketoacidosisHyponatremiaHyperosmolar hyperglycemic state (HHS)Hypernatremia

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For education only. Check the inputs and the population the score was validated in before acting on it. Not a substitute for clinical judgment.