/Anion Gap

Anion Gap

Evaluates metabolic acidosis

Sodium (Na)
mEq/L
Chloride (Cl)
mEq/L
Bicarbonate (HCO3)
mEq/L

Total Score

0

Abnormally low Anion Gap. Check lab errors or hypoalbuminemia.

-992Moderate
311+Low
12999+High

Disclaimer: The clinical scoring and algorithms on this platform are intended strictly for professional informational purposes. They do not constitute a definitive medical diagnosis, treatment, or clinical decision. The final judgment and responsibility lie with the treating physician.

Yasal Uyarı: Bu platformdaki klinik skorlamalar ve algoritmalar yalnızca sağlık profesyonellerini bilgilendirme amaçlıdır. Herhangi bir kesin tıbbi teşhis, tedavi veya klinik karar yerine geçemez. Nihai karar ve sorumluluk hastayı yatak başında değerlendiren hekime aittir.

Clinical Overview

The serum Anion Gap is a fundamental calculation in evaluating acid-base disorders, particularly metabolic acidosis. It represents the unmeasured anions in the plasma (primarily negatively charged proteins like albumin, sulfates, and phosphates). An elevated anion gap indicates the presence of exogenous or endogenous pathological acids (e.g., ketones, lactate, toxic alcohols) commonly remembered by the MUDPILES mnemonic.

Clinical Pearl

Albumin constitutes the bulk of the normal unmeasured anions. Therefore, in a critically ill patient with severe hypoalbuminemia, the 'baseline' anion gap is inherently lower. You must calculate the 'Corrected Anion Gap'; roughly, for every 1 g/dL drop in albumin below 4.0, add 2.5 mEq/L back to the calculated anion gap to avoid missing a hidden high-gap acidosis.

Pitfalls & Warnings

  • Does not account for unmeasured cations (e.g., lithium toxicity, hypergammaglobulinemia in multiple myeloma) which can cause an artificially low or even negative anion gap.
  • Severe hypercalcemia or hypermagnesemia can also falsely lower the gap.

Academic References

Kraut JA, Madias NE. Serum anion gap: its uses and limitations in clinical medicine. Clin J Am Soc Nephrol. 2007;2(1):162-174.

Disclaimer: The clinical scoring and algorithms on this platform are intended strictly for professional informational purposes. They do not constitute a definitive medical diagnosis, treatment, or clinical decision. The final judgment and responsibility lie with the treating physician.