Sodium Correction Rate for Hyponatremia

Calculates sodium deficit and recommended infusion rate for correcting hyponatremia. Emphasizes safe correction limits to prevent osmotic demyelination syndrome (ODS).

kg
Patient body weight in kg.
Total body water: 0.5 L/kg for females/older, 0.6 L/kg for males.
mEq/L
Current serum sodium.
mEq/L
Target sodium. For chronic hyponatremia, aim for 4-8 mEq/L rise in 24 hours.
3% saline = 513 mEq/L sodium. 0.9% saline = 154 mEq/L. LR = 130 mEq/L.

References

  1. Hyponatremia - StatPearls — NCBI Bookshelf/NIH (2025)
  2. Hypertonic Saline for Hyponatremia: Meeting Goals — Cureus/PMC (2023)

Note: 3% sodium chloride contains 513 mEq/L sodium. 100 mL bolus = ~51.3 mEq. The Adrogue-Madias formula estimates change in serum Na per liter: (Na_fluid - CurrentNa) / (TBW + 1). For rapid correction of severe symptoms, bolus therapy is safer than continuous infusion.

Warnings & Limitations

  • CHRONIC hyponatremia (>48h): Limit correction to <8 mEq/L in 24h, preferably <6 mEq/L if high ODS risk.
  • High ODS risk: chronic hyponatremia, hypokalemia, malnutrition, alcoholism, liver disease.
  • ACUTE symptomatic: Can use 100-150 mL 3% saline bolus over 10-20 min; goal 4-6 mEq/L rise in first 4-6 hours.
  • Never exceed 10 mEq/L in first 24 hours in most patients.
  • If correcting too rapidly: use desmopressin (DDAVP) clamp + D5W to halt/reverse correction.
  • Monitor serum sodium every 2-4 hours during active correction.