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Corrected Sodium (Hyperglycaemia)

Sodium Resolver

Hyperglycaemic Offset

Primary Inputs

Measured Sodium (Na)

Glucose (mg/dL)

Osmotic Flux

Enter sodium and glucose to calculate the corrected sodium level.

Guidelines & Evidence

Verified

Last Review: 2026

When to Use

What is Corrected Sodium (Hyperglycemia Correction)?

Corrected sodium (also called glucose-corrected sodium or Katz correction) is a calculated value that estimates the "true" serum sodium concentration in patients with hyperglycemia (elevated blood glucose). Glucose is an osmotically active solute. When blood glucose rises significantly (typically >200-300 mg/dL, >11-17 mmol/L), water is drawn from the intracellular space (inside cells) into the extracellular space (bloodstream) due to the osmotic gradient. This dilutes serum sodium, causing a factitious (or "dilutional") hyponatremia. The corrected sodium calculation estimates what the sodium concentration would be if the glucose were normal (e.g., 100 mg/dL or 5.6 mmol/L). This value is critical for guiding fluid management in diabetic emergencies: if the corrected sodium is low, the patient has true hyponatremia (total body water excess relative to sodium); if the corrected sodium is high or normal, the patient is water-depleted (despite a low measured sodium), and hypotonic fluids (0.45% NaCl) may be appropriate.

Primary Clinical Indications

Diabetic Ketoacidosis (DKA) – All patients with DKA and glucose >250 mg/dL should have corrected sodium calculated to guide fluid selection (0.9% vs 0.45% NaCl) and assess true sodium status

Hyperosmolar Hyperglycemic State (HHS) – Essential for fluid management in HHS, where glucose is often >600 mg/dL and sodium may be factitiously low (or normal) despite profound water depletion

Pediatric DKA (cerebral edema prevention) – Failure to correct sodium may lead to inappropriate fluid choices (e.g., 0.45% NaCl when corrected sodium is normal or high, risking too-rapid correction of hyperosmolality). Monitoring corrected sodium trend helps guide when to add dextrose to IV fluids

Management of severe hyperglycemia in hospitalized patients – Any patient with glucose >300 mg/dL (e.g., steroid-induced hyperglycemia, stress hyperglycemia, TPN-related) should have corrected sodium calculated before diagnosing hyponatremia

Differentiating true from dilutional hyponatremia – If measured sodium is low (e.g., 125 mEq/L) but glucose is elevated (e.g., 600 mg/dL), corrected sodium may be 130-135 mEq/L (normal), indicating factitious hyponatremia. True hyponatremia requires different management (fluid restriction, vasopressin antagonists)

Monitoring response to insulin therapy – As glucose falls with insulin, water shifts back into cells, and measured sodium should rise. A failure of measured sodium to rise (or a paradoxical fall) indicates worsening true hyponatremia or excessive free water administration

Assessing risk of cerebral edema (pediatric DKA) – A rise in corrected sodium >3 mEq/L over 4 hours (or >12 mEq/L over 24 hours) is associated with increased risk of cerebral edema. Serial corrected sodium measurements guide fluid adjustment

Contraindications / Limitations

Not valid in severe hyperlipidemia or hyperproteinemia – Pseudohyponatremia (from lipids or paraproteins) coexisting with hyperglycemia confounds interpretation. Ionized sodium (direct ISE) is preferred.

Not valid in severe renal failure (oliguria) – The correction formula assumes normal renal handling of water; in oliguric renal failure, free water excretion is impaired, and the dilutional effect may be attenuated or prolonged.

Not a substitute for clinical assessment – Corrected sodium is an estimate. Some studies suggest it may overcorrect or undercorrect in individual patients. Use with clinical judgment.

Correction factor depends on glucose level – The classic 1.6 factor (Katz) was derived from studies with glucose <600 mg/dL. For glucose >600 mg/dL, Hillier suggests a higher factor (2.4). For glucose <200 mg/dL, correction is not needed (dilutional effect negligible).

Assumes normal serum osmolality relationship – In HHS, serum osmolality is often >320 mOsm/kg. The correction formula is still valid but must be interpreted alongside osmolality and neurological status.

Not applicable for chronic hyperglycemia – In poorly controlled diabetes with chronic glucose elevation (e.g., 200-300 mg/dL for weeks), the osmotic shift reaches equilibrium, and the correction factor may differ (chronic adaptation). Use caution in non-acute settings.

Comparison of Correction Factors (Katz vs Hillier vs Others)

Author/Year	Correction Factor	Glucose Range	Population	Clinical Use
Katz (1973)	1.6 mEq/L Na decrease per 100 mg/dL glucose increase above 100 mg/dL	Any hyperglycemia (derived from studies with glucose <600 mg/dL)	General medical inpatients	Most widely used; simple, single factor. Suitable for most clinical settings.
Hillier (1999)	Varies: 2.4 mEq/L per 100 mg/dL for glucose >400 mg/dL; 2.0 mEq/L per 100 mg/dL for glucose 200-400 mg/dL	Up to 1,500 mg/dL	65 hyperglycemic patients (DKA, HHS, other)	More accurate at very high glucose (>400 mg/dL). Preferred in HHS and severe DKA.
Moran & Jamison (1978)	1.6 mEq/L (same as Katz)	Limited range	Not widely used	Historical; same as Katz.
Turchin (2005)	1.6 mEq/L (validated in large cohort)	Mean glucose 415 mg/dL (range 200-1,200)	12,000+ hospitalized patients (retrospective)	Confirmed Katz factor in large dataset; no need for adjustment based on renal function?
Pediatric DKA (ISPAD)	1.6 mEq/L (Katz) OR 1.6/3? Actually ISPAD uses 1.6	Pediatric DKA	Children	Same as Katz; monitor trend (rise of 3 mEq/L in 4 hours predicts cerebral edema)
UK Joint British Diabetes Societies (JBDS)	1.5-2.0 mEq/L (range), often uses 1.6	DKA and HHS	Adult inpatients	Recommends Katz; also recommends monitoring measured sodium rise (should increase as glucose falls)

Related Scores in Practice

In clinical practice, this assessment is frequently evaluated alongside other validated measures. Depending on the patient's presentation and specific diagnostic requirements, you may also need to utilize the Anion Gap Calculator, Calculated Osmolality, Dka Management, Hhs Management or the Delta Sodium Glucose Ratio to formulate a comprehensive care plan.

Last Comprehensive Review: 2026

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