Urine Anion Gap
Urine Anion Gap
mEq/L
mEq/L
mEq/L
Result:
–
–
–
Detects urine acidosis for evaluation of non-gap metabolic acidosis.
Why Use
This simple urine test can help differentiate the causes of a non-gap metabolic acidosis (HARDUP): Hyperchloremia Acetazolamide, Addison’s disease Renal tubular acidosis Diarrhea, vomiting, ileostomies, fistulae Ureteroenteric fistulae Pancreatoduodenal fistulae
When to Use
The patient with an unexplained non-gap metabolic acidosis. The patient with a mixed metabolic acidosis. Evaluation for suspected RTA .
Formula
Urine Anion Gap (mEq/L) = Na + + K + - Cl -
Management
Remember that hyperchloremic fluids can worsen these acidoses; consider fluids with lower chloride concentrations (like LR ).