A note on Sodium (Na) correction in severe hyperglycemia

To correct Sodium (Na) in hyperglycemia above 200 mg/dL the most commonly used correction factor is a 1.6 mEq per L increase in serum sodium for every 100 mg per dL increase in glucose concentration. 

 At least one study argue that this correction factor may not work if glucose is more than 500 mg/dL. The authors conclude that the conventional correction factor used to correct serum sodium in patients with hyperglycemia is inaccurate and leads to serious underestimation of serum sodium values in association with glucose levels higher than 500 mg per dL. Therefore, the authors recommend using 2.4 as the correction factor to prevent such underestimations, particularly in patients with severe hyperglycemia who require more of a correction.



Reference:

Hillier TA, et al. Hyponatremia: evaluating the correction factor for hyperglycemia. Am J Med. April 1999;106:399–403.