ICU Map

Delta Gap

How far the anion gap has risen above normal — the numerator used when assessing for a concurrent metabolic process.

Formula

Delta gap = (Na − (Cl + HCO3)) − 12

Result

Enter all values to see the result.

Limitations

  • Assumes a fixed normal anion gap of 12 mEq/L, which varies somewhat by laboratory and isn't individually corrected for albumin here.
  • On its own, the delta gap doesn't reveal a concurrent process — it's the numerator of the delta ratio, which is the more informative calculation (see Delta Ratio).
  • Least reliable when the anion gap is only mildly elevated, where measurement variability has more relative influence.

References

  • Standard derivation from the anion gap; see also Delta Gap in the Physiology Library.

Clinical Context & Relevant Topics (3)

Disease Reference
Acid-Base Disorders: Comprehensive Critical Care Approach

Stepwise 6-step interpretation algorithm, compensation formulas, albumin-corrected anion gap, delta ratio, and Stewart physicochemical (SID) principles.

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Metabolic Acidosis: HAGMA, NAGMA, & Bicarbonate Evidence

Differential diagnosis (GOLD MARK vs HARDCARP), toxic alcohol osmolar gaps, Urine Anion Gap, and current sodium bicarbonate evidence including BICAR-ICU and BICARICU-2.

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Diabetic Ketoacidosis (DKA)

Pathophysiology, SGLT2i euglycemic DKA, balanced fluid resuscitation, potassium-before-insulin safety rules, dextrose addition kinetics, and subcutaneous transition.

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Relevant Clinical Pathways (6)

Decision Protocols
Renal Replacement Therapy & CRRT Initiation

From urgent 'AEIOU' indication screening and modality selection to vascular access, dosing, and anticoagulation.

Launch Pathway →
Acute Severe Metabolic Acidosis Evaluation

From primary disorder confirmation and Anion Gap calculation to Winter's compensation, delta ratio, and targeted source control.

Launch Pathway →