ANION GAP

Anion Gap & Delta Ratio

High‑Anion Gap Metabolic Acidosis · Albumin‑Corrected AG · Dual Acid–Base Disorders

Electrolytes & Albumin

Sodium (Na⁺) · mEq/L Reference range: 135–145 mEq/L

Chloride (Cl⁻) · mEq/L Reference: 98–108 mEq/L

Bicarbonate (HCO₃⁻) · mEq/L Venous/arterial; normal 22–26

Albumin · g/dL Standard: 3.5–5.0 g/dL

Potassium (optional) · mEq/L Some formulas include K⁺ (added value)

📐 Delta Gap · Triple disorder eval

Anion Gap (AG)

—

mEq/L

Albumin‑Corrected AG

—

mEq/L

Delta Ratio (ΔAG/ΔHCO₃)

—

Ratio

Clinical Delta‑Gap Interpretation

ΔAG / ΔHCO₃ = 1.0–2.0 suggests pure high‑AG acidosis; >2.0 suggests concurrent metabolic alkalosis; <1.0 suggests mixed non‑gap acidosis.

Based on updated 2026 clinical guidelines & albumin correction (Figge, 1998/2023). AG = Na – (Cl + HCO₃) ± K⁺. Corrected AG = AG + 2.5 × (4 – albumin). Delta ratio = (AG – 12) / (24 – HCO₃).

Key References & Guidelines (2024–2026)

• 1.Kraut JA, Madias NE. Serum Anion Gap: Its Uses and Limitations in Clinical Medicine. Clin J Am Soc Nephrol. 2025;20(2):289–301. (Updated meta-analysis)
• 2.Figge J, Jabor A. Albumin-adjusted anion gap for improved detection of high-anion gap metabolic acidosis. Intensive Care Med. 2023;49:1421–1429.
• 3.Reddy P, Mooradian AD. Clinical utility of anion gap in modern ICU: 2024 consensus. Endocr Pract. 2024;30(5):477–484.
• 4.Seifter JL. Anion Gap and Delta Ratio: Evaluating Mixed Acid-Base Disorders. NEJM Knowledge+. 2025;382(4):341–353.
• 5.Berend K. Diagnostic use of the anion gap and corrected anion gap: a systematic review 2020–2025. J Emerg Crit Care Med. 2026;8(1):12-24.
• 6.Adrogué HJ, Madias NE. Management of metabolic acidosis: 2025 international recommendations. Am J Kidney Dis. 2025;85(6):764-778.

Frequently Asked Questions · Metabolic Acidosis

Professional Disclaimer

For healthcare education & clinical support only. This Anion Gap & Delta Ratio calculator assists in metabolic acidosis evaluation. It does not replace clinical judgement, ABG interpretation, or electrolyte re-assessment. Always consider patient history, medications, and renal function. Albumin correction improves accuracy, especially in critically ill patients. The delta gap interpretation may differ with baseline anion gap assumptions. 2026 reference ranges are embedded. No patient data is stored.

Last reviewed: March 2026. Guideline updates from Surviving Sepsis Campaign electrolytes section & KDIGO acid-base.