How do you correct sodium for hyperglycemia in DKA/HHS?

How do you correct sodium for hyperglycemia in DKA/HHS?

• A. Corrected Na+ = measured Na+ + 1.6 mEq/L for every 100 mg/dL glucose above normal.
• B. Corrected Na+ = measured Na+ - 1.0 mEq/L for every 100 mg/dL glucose above normal.
• C. Corrected Na+ = measured Na+ + 5 mEq/L for every 100 mg/dL glucose above normal.
• D. Corrected Na+ equals measured Na+.

Answer: (A)

High glucose increases plasma osmolality and pulls water from inside cells into the extracellular space, diluting serum sodium. To estimate the true sodium level in this dilutional state, you correct Na+ for hyperglycemia using the standard adjustment: add about 1.6 mEq/L to the measured Na+ for every 100 mg/dL by which glucose exceeds normal (roughly 100 mg/dL). For example, if glucose is 400 mg/dL (300 mg/dL above normal) and measured Na+ is 130 mEq/L, the correction is 1.6 × 3 = 4.8, so the corrected Na+ is about 134.8 mEq/L (≈135 mEq/L). This helps guide fluid and electrolyte management in DKA/HHS. Subtracting a value, or adding a larger amount per 100 mg/dL, or leaving Na+ uncorrected, would misrepresent the patient’s true sodium status because they don’t reflect the dilutional effect of hyperglycemia.

High glucose increases plasma osmolality and pulls water from inside cells into the extracellular space, diluting serum sodium. To estimate the true sodium level in this dilutional state, you correct Na+ for hyperglycemia using the standard adjustment: add about 1.6 mEq/L to the measured Na+ for every 100 mg/dL by which glucose exceeds normal (roughly 100 mg/dL).

For example, if glucose is 400 mg/dL (300 mg/dL above normal) and measured Na+ is 130 mEq/L, the correction is 1.6 × 3 = 4.8, so the corrected Na+ is about 134.8 mEq/L (≈135 mEq/L). This helps guide fluid and electrolyte management in DKA/HHS.

Subtracting a value, or adding a larger amount per 100 mg/dL, or leaving Na+ uncorrected, would misrepresent the patient’s true sodium status because they don’t reflect the dilutional effect of hyperglycemia.