Anion Gap Calculator

Anion Gap

Albumin-Corrected

Interpretation

Understanding the Anion Gap

AG = Na - (Cl + HCO3). Normal 3-12 mEq/L. Elevated indicates unmeasured anions, often from metabolic acidosis.

Albumin-corrected: for every 1 g/dL decrease in albumin below 4.0, AG decreases by ~2.5 mEq/L.

MUDPILES mnemonic identifies elevated AG causes: Methanol, Uremia, DKA, Propylene glycol, Isoniazid, Lactic acidosis, Ethylene glycol, Salicylates.

Disclaimer: This calculator is for informational purposes only and does not constitute financial, tax, or legal advice. Always consult a qualified professional for decisions specific to your situation.

Frequently Asked Questions

AG formula?

AG = Na - (Cl + HCO3). Some include K: AG = (Na+K) - (Cl+HCO3), normal 10-20.

Elevated AG causes?

MUDPILES: Methanol, Uremia, DKA, Propylene glycol, INH/Iron, Lactic acidosis, Ethylene glycol, Salicylates.

Normal range?

3-12 mEq/L (without K). AG >20 is significantly elevated, needs urgent evaluation.

Why correct for albumin?

Albumin is a major unmeasured anion. Low albumin reduces AG by ~2.5 per 1 g/dL decrease.

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