Urine Anion Gap

id

2045

full_title

Urine Anion Gap

short_title

Urine Anion Gap

med_description

Detects urine acidosis for evaluation of non-gap metabolic acidosis.

description

The Urine Anion Gap is used for differential diagnosis in metabolic acidosis using measured ions in the urine.

keywords

urine anion gap, anion gap, urine ag, urine nh4, nh4, diarrheal cause, RTA, renal tubular acidosis

complaint

[ "Diarrhea", "Shortness of Breath" ]

formula

Urine Anion Gap (mEq/L) = Na++ K+- Cl-

evidence

measurements

[ { "name": "Urine Potassium", "unit": "k_urine", "error_min": "-1", "error_max": "300", "warn_min": "0", "warn_max": "100", "conversion": "1", "normal_max_si": "0", "normal_max_us": "0", "normal_min_si": "0", "normal_min_us": "0", "units_si": "mmol/L", "units_us": "mEq/L" }, { "name": "Urine Chloride", "unit": "cl_urine", "error_min": "-1", "error_max": "301", "warn_min": "1", "warn_max": "151", "conversion": "1", "normal_max_si": "250", "normal_max_us": "250", "normal_min_si": "80", "normal_min_us": "80", "units_si": "mmol/L", "units_us": "mEq/L" }, { "name": "Urine Sodium", "unit": "na_urine", "error_min": "0", "error_max": "500", "warn_min": "1", "warn_max": "260", "conversion": "1", "normal_max_si": "260", "normal_max_us": "260", "normal_min_si": "100", "normal_min_us": "100", "units_si": "mmol/L", "units_us": "mEq/L" } ]

information

refrences

{ "Clinical Practice Guidelines": [], "Manufacturer Website": [], "Original/Primary Reference": [ { "href": "https://www.ncbi.nlm.nih.gov/pubmed/3752165", "text": "Goldstein MB, Bear R, Richardson RM, Marsden PA, Halperin ML. The urine anion gap: a clinically useful index of ammonium excretion. Am J Med Sci. 1986 Oct;292(4):198-202." } ], "Other References": [], "Outcomes": [], "Validation": [ { "href": "https://www.ncbi.nlm.nih.gov/pubmed/8546137", "text": "Kim GH, Han JS, Kim YS, Joo KW, Kim S, Lee JS. Evaluation of urine acidification by urine anion gap and urine osmolal gap in chronic metabolic acidosis. Am J Kidney Dis. 1996 Jan;27(1):42-7." } ], "Validations": [] }

pearls

usecase

• The patient with an unexplained non-gap metabolic acidosis.
• The patient with a mixed metabolic acidosis.
• Evaluation for suspected RTA.

reasons

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

next_advice

next_actions

next_management

Remember that hyperchloremic fluids can worsen these acidoses; consider fluids with lower chloride concentrations (like LR).

diseases

[ "Acid-Base Disturbance" ]

instructions

published

2022-04-21T20:29:06.416Z

purpose

[ "Formula" ]

search_terms

[ "metabolic acidosis", "nh4", "urine anion gap", "anion gap", "urine ag", "urine nh4" ]

seo

{ "keywords_en": "urine anion gap, anion gap, urine ag, urine nh4, nh4, diarrheal cause, RTA, renal tubular acidosis", "meta_description_en": "The Urine Anion Gap is used for differential diagnosis in metabolic acidosis using measured ions in the urine." }

specialty

[ "Critical Care", "Critical Care (Pediatric)", "Emergency Medicine", "Endocrinology", "Gastroenterology", "Hospitalist Medicine", "Internal Medicine", "Nephrology", "Pediatrics", "Urology" ]

departments

[ "Endocrine and Metabolic" ]

tags

[]

version_number

1

versions

[]

related

[ { "calcId": 91, "short_title_en": "Serum Osmolality", "slug": "serum-osmolality-osmolarity" }, { "calcId": 117, "short_title_en": "Winters' Formula", "slug": "winters-formula-metabolic-acidosis-compensation" }, { "calcId": 2074, "short_title_en": "Urine Output", "slug": "urine-output-fluid-balance" } ]

ismed

false

section

[ "whenToUseViewed", "whyUseViewed", "nextStepsViewed", "evidenceViewed" ]

cleaned_departments

[ "endocrine" ]

cleaned_use

[ "The patient with an unexplained non-gap metabolic acidosis.", "The patient with a mixed metabolic acidosis.", "Evaluation for suspectedRTA." ]

pub

true