Urine Anion Gap

URINE ANION GAP

by Brian Rosenthal and Stephen Fadem

Add paragraph text. Click “Edit Text” to update the font, size and more. To change and reuse text themes, go to Site Styles.

The urine anion gap measures positive and negative ions. Since urine ammonia is not measured, it is the gap anion. Healthy kidneys can excrete ammonia and trap it as ammonium to rid the body of excess acid (H+). In renal tubular acidosis or in any condition where ammonia is not secreted and trapped, the gap will be less.

The UAG is not valid if the urine sodium is < 20 mEq/L or in cases of volume depletion, low chloride excretion.

References

Hilton,JG, et al. The urine anion gap: the critical clue to resolve a diagnostic dilemma in a patient with ketoacidosis

Diabetes Care, 7:486-490,1984.

DISCLAIMER: All calculations must be checked for accuracy and confirmed before clinical use. These applications are for illustrative and educational purposes only. A formula cannot replace the clinical judgment of a physician.

Neither Interoperable software nor its associated authors or other entities can warranty the accuracy of this information for clinical management, nor shall be liable for any adverse consequences resulting from the use of this application.