Endocrine & Metabolic Equation Moderate evidence Clinical review pending v1.0.0

Anion Gap (with albumin correction)

Is there an elevated anion gap metabolic acidosis?

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About this tool

Serum anion gap with optional albumin correction and delta ratio.

Intended use

Patients with metabolic acidosis or suspected toxic ingestion.

Outcome

Unmeasured anions

Time horizon

Point in time

Limitations

Reference ranges are analyser-specific.

Clinical problems

Acid–base and electrolytes

Evidence

Evidence level

Moderate evidence

Physiological calculation; reference intervals are laboratory-specific. Methodology

Evidence summaries for this tool are awaiting independent clinical review. Statistics are shown only where they could be attributed to a specific publication.

References

Review / updateKraut JA, Madias NE. Serum anion gap: its uses and limitations in clinical medicine. Clin J Am Soc Nephrol 2007;2:162-174. Find on PubMed (opens in a new tab)
Original publicationFigge J, Jabor A, Kazda A, Fencl V. Anion gap and hypoalbuminemia. Crit Care Med 1998;26:1807-1810. Find on PubMed (opens in a new tab)

Version history

Version	Formula	Effective	Reviewer	Changes
v1.0.0	Na − (Cl + HCO3); Figge 1998 albumin correction	2026-10-03	—	Initial implementation with reference test vectors.

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Clinical decision support only. Interpret results in the context of the individual patient and current guidance; HumanPulse does not replace professional medical judgment.