Hyperglycemia Sodium Correction Calculator

How does this hyperglycemia sodium correction calculator work?

This is a useful health tool allowing you to determine the corrected sodium level in cases of hyperglycemia by two different formulas the first by Katz, 1973 and the second revised by Hillier in 1999 who changed the sodium correction factor from 1.6 mEq/L to 2.4 mEq/L.

For the hyperglycemia sodium correction calculator to work you need to input the measured sodium in mEq/L and the serum glucose in mg/dL.

The formulas employed are the following:

- Corrected Sodium (Katz) = Measured sodium + 0.016 * (Serum glucose - 100)

- Corrected Sodium (Hillier) = Measured sodium + 0.024 * (Serum glucose - 100)

Example calculation

Let’s take the case of a patient with glucose levels of 210 mg/dL and measured sodium of 140 mEq/L. The figures displayed by this calculator are:

■ The Corrected Sodium by Katz, 1973 formula is 141.76 mg/dL.

■ The Corrected Sodium by Hillier, 1999 formula is 142.64 mg/dL.

Hyperglycemia and sodium correction

In patients diagnosed with high levels of glucose, there can appear a false result of low serum sodium because of the metabolic reactions in the body as described below. Thus, this value should be corrected to reflect the real condition of the body.

Hyperglycemia is known to associate with a temporary translational hyponatremia caused by the migration of plasma glucose in the cells which displaces water in the extracellular space. This shift in body fluids determines the change in serum Na.

This in turn is reflected in a decrease of 1.6 mEq/L in Na concentration for every 100 mg/dL / 5.6 mmol/L of extra glucose. There have been new studies which aim to promote that the decrease is actually at the level of 2.4 mEq/L. Therefore the nowadays discussion is whether this correction factor should be 1.6 or 2.4 but the overall effect of this association remains and should be carefully monitored.

References

1) Katz MA. (1973) Hyperglycemia-induced hyponatremia--calculation of expected serum sodium depression. N Engl J Med; 18;289(16):843-4.

2) Hillier TA, Abbott RD, Barrett EJ. (1999) Hyponatremia: evaluating the correction factor for hyperglycemia. Am J Med; 106(4):399-403.