Why use it

Prevents osmotic demyelination syndrome (ODS) from overly rapid hyponatremia correction. Prevents cerebral edema from overly rapid hypernatremia correction. Guides fluid selection and rate.

About

The Adrogué-Madias formula estimates the change in serum sodium produced by 1 liter of any infusate. This guides safe correction of both hyponatremia and hypernatremia by selecting appropriate fluids and infusion rates to stay within safe correction limits (typically ≤ 8-10 mEq/L per 24 hours for hyponatremia).

When to use

Hyponatremia requiring correction
Hypernatremia requiring correction
Planning IV fluid therapy for sodium disorders

Formula

ΔNa per 1L infusate = (Infusate Na - Serum Na) / (TBW + 1) TBW = Weight × correction factor (0.6 male, 0.5 female, 0.45 elderly female)

Pearls & pitfalls

Safe hyponatremia correction: ≤ 8-10 mEq/L in 24h, ≤ 18 mEq/L in 48h.
High ODS risk (alcoholism, malnutrition, hypokalemia, liver disease): limit to ≤ 6-8 mEq/L per 24h.
This formula estimates change per LITER — adjust for actual volume infused.
Total body water (TBW) = Weight × 0.6 (males) or 0.5 (females).
Common infusate Na: 3% NaCl = 513 mEq/L, NS = 154 mEq/L, LR = 130 mEq/L, D5W = 0, half-NS = 77 mEq/L.
Always account for ongoing losses and K replacement (K raises Na when correcting hyponatremia).

Next steps

Hyponatremia: Correct ≤ 8-10 mEq/L per 24h (≤ 6-8 if high ODS risk). Check Na every 2-4h during active correction. Hypernatremia: Correct ≤ 10-12 mEq/L per 24h. If overcorrecting, give DDAVP to slow correction.

Evidence

Adrogué and Madias (N Engl J Med, 2000). Widely adopted in nephrology practice. Multiple clinical guidelines recommend formula-based correction planning with frequent Na monitoring.

References

Adrogué HJ, Madias NE. Hyponatremia. N Engl J Med. 2000;342(21):1581-1589. — link

Sodium Correction Rate (Adrogué-Madias)

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