Corrected Na (mEq/L) = measured Na mEq/L+ 0.016 * (glucose mg/ dL – 100) (Katz)
Corrected Na (mEq/L) = measured Na mEq/L + 0.024 x (glucose mg/dL - 100) (Hillier)
Effective serum osmolality (mOsm/kg) = 2 [measured Na (mEq/L)] + glucose (mg/dl)/18

REFERENCES
Katz MA. Hyperglycemia-induced hyponatremia--calculation of expected serum sodium depression. N Engl J Med. 1973; 18;289(16):843-4. PMID: 4763428.
Hillier TA, Abbott RD, Barrett EJ. Hyponatremia: evaluating the correction factor for hyperglycemia. Am J Med. 1999; 106(4):399-403. PMID:10225241
Kitabchi AE, et. al. Management of hyperglycemic crises in patients with diabetes. Diabetes Care. 2001 Jan;24(1):131-53. doi: 10.2337/diacare.24.1.131. PMID:11194218

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