Urine anion gap (urinary NH4⁺ surrogate) Calculator
Indirect clue to urinary ammonium in normal anion gap acidosis
When to use it
Use to differentiate renal tubular acidosis from GI bicarbonate losses in non-anion-gap metabolic acidosis.
Category
Acute Kidney Injury (AKI) Workup
References
- Batlle DC et al. The use of the urinary anion gap in the diagnosis of hyperchloremic metabolic acidosis. N Engl J Med. 1988;318:594-9. PMID: 3344005
- Kamel KS et al. Use of Urine Electrolytes and Urine Osmolality in the Clinical Diagnosis of Fluid, Electrolytes, and Acid-Base Disorders. Kidney Int Rep. 2021;6:1211-1224. PMID: 34013099
About NephroMind
This calculator is part of NephroMind, a free clinical decision-aid platform from the Arab Society of Nephrology and Renal Transplantation (ASNRT) — over 128 bedside nephrology calculators plus a renal drug-dosing database, coded by a practicing transplant nephrologist.