Corrected Sodium for Hyperglycemia

Calculates the corrected serum sodium accounting for dilutional effect of severe hyperglycemia.

mEq/L

Measured serum sodium concentration

mg/dL

Serum glucose in mg/dL

Katz uses 1.6 mEq/L per 100 mg/dL; Hillier uses 2.4 mEq/L per 100 mg/dL

Enter sodium and glucose to calculate corrected sodium

Clinical Notes & Warnings

  • Act on corrected sodium level, not measured sodium.
  • Katz formula (1.6 mEq/L per 100 mg/dL) is most widely used but may underestimate in severe hyperglycemia.
  • Hillier formula (2.4 mEq/L per 100 mg/dL) may be more accurate in severe hyperglycemia (>400 mg/dL).
  • Correction factor may vary by population (ICU patients, diabetes status).
  • Glucose must be in mg/dL.

Hyperglycemia causes osmotic shift of water into extracellular space, diluting sodium. Formulas estimate sodium if glucose were normalized to 100 mg/dL.