End
Sodium Correction
Calculates the actual sodium level in patients with hyperglycemia. Act on the corrected sodium level, not the measured sodium level, when planning fluid replacement.
Measured Sodium (Na)
Serum sodium from laboratory results
Serum Glucose
Blood sugar in mg/dL
–
mEq/L
Analyzing…
Katz Formula (Classic): -%
Hillier Formula (Modern): -%
| Clinical Status (Katz Corrected) | Recommended Action |
|---|---|
| Hyponatremia (< 135 mEq/L) | Rule out pseudohyponatremia (check osmolality) and plan targeted therapy. |
| Normal (135 – 145 mEq/L) | Euvolemic state. Focus on glucose control and monitoring fluid balance. |
| Hypernatremia (> 145 mEq/L) | True hypernatremia. Calculate free water deficit and start appropriate fluid (e.g., 0.45% NaCl) replacement. |
1
Risk of Pseudohyponatremia: Hyperglycemia causes an osmotic shift of water from the intracellular to extracellular space, creating dilutional hyponatremia. There is no true sodium deficit; osmolality is generally high.
2
Frequent Lab Monitoring: As glucose enters cells with insulin and fluid therapy, sodium levels will change. Na levels are dynamic; repeat lab tests regularly.
3
Role of the Hillier Formula: The Katz (1973) formula uses a factor of 1.6 per 100 mg/dL glucose increase, while Hillier (1999) argues 2.4 mEq/L is more accurate for larger osmotic shifts. Knowing both enhances clinical judgment.
