Aldosterone, Urine
General Information
- Lab Name
- Aldosterone, Urine
- Lab Code
- RUALDO
- Epic Ordering
- Aldosterone, Urine (Sendout)
- External Test Id
- ALDU
- Description
Useful For: Investigation of primary aldosteronism (eg, adrenal adenoma/carcinoma and adrenal cortical hyperplasia) and secondary aldosteronism (renovascular disease, salt depletion, potassium loading, cardiac failure with ascites, pregnancy, Bartter syndrome).
- References
- Loeuille GA, Racadot A, Vasseur P, Vandewalle B: Blood and urinary aldosterone levels in normal neonates, infants and children. Pediatrie 1981;36:335-344.
- Synonyms
- ALDU, Urine Aldosterone
- Components
-
Code Name RUALDI Aldosterone Interval RUALDV Aldosterone Volume RUALDR Aldosterone, Urine
Interpretation
- Method
High-Performance Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS)
- Reference Range
- See individual components
- Ref. Range Notes
Reference Values:
Age Reference Range 0-30 days: 0.7-11.0 mcg/24 hours¹ 31 days - 11 months: 0.7-22.0 mcg/24 hours¹ > or = 1 year: 2.0-20.0 mcg/24 hours Interpretation: Urinary aldosterone excretion greater than 12 mcg/24 hours as part of an aldosterone suppression test is consistent with hyperaldosteronism.
- Interferences and Limitations
Cautions: The plasma renin activity (PRA) cannot be interpreted if the patient is being treated with spironolactone (Aldactone). Spironolactone (Aldactone) should be discontinued for 4 to 6 weeks before testing.
Angiotensin converting enzyme (ACE) inhibitors have the potential to "falsely elevate" PRA. Therefore, in a patient treated with an ACE-inhibitor, the findings of a detectable PRA level or a low sodium aldosterone (SA)/PRA ratio do not exclude the diagnosis of primary aldosteronism. In addition, a strong predictor for primary aldosteronism is a PRA level undetectably low in a patient taking an ACE-inhibitor.
- References
- Loeuille GA, Racadot A, Vasseur P, Vandewalle B: Blood and urinary aldosterone levels in normal neonates, infants and children. Pediatrie 1981;36:335-344.
Ordering & Collection
- Specimen Type
- Urine
- Collection
-
Patient Preparation: If the patient is taking spironolactone (Aldactone), it should be discontinued for 4 to 6 weeks before specimen collection.
Sample Collection:
- Preferred: Add 25 mL of 50% acetic acid as a preservative to a timed urine collection container. Use 15 mL of 50% acetic acid for patients <5 years. Preservative is intended to achieve a pH of between approximately 2 and 4.
- Urine collections without preservative are also accepted. Refer to Mayo Urine Preservatives: Collection and Transport for 24 Hour Urine Specimens.
- Instruct patient to collect specimen for 24 hours.
Note: All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. Samples with pH<2.0 or >8.0 are unacceptable for testing.
- Handling Instructions
Outside Laboratories:
- Mix and measure urine. Record total volume and collection interval on the requisition.
- Aliquot 10 mL urine and refrigerate.
Stability: Refrigerated (Preferred): 28 days; Frozen: 28 days; Ambient: 14 days.
- Quantity
-
requested: 10 mL urine
minimum: 1 mL urine
Processing
- Processing
- Mix and measure urine.
- Record collection interval and total volume.
- At login, enter the collection interval (RUALDI) and volume (RUALDV) in the result-at-entry fields.
- Aliquot 10 mL urine into a separate, plastic screw-top vial. Refrigerate.
Sendouts, order Mayo Test: ALDU.
Stability: Refrigerated (Preferred): 28 days; Frozen: 28 days; Ambient: 14 days.
Performance
- LIS Dept Code
- Sendouts Mayo Lab (RF) (MARF)
- Performing Location(s)
-
Sendout Mayo Clinic Laboratories (Superior Drive)
800-533-17103050 Superior Drive NW
Rochester, MN 55901 - Frequency
- Performed: Tuesday, Thursday. Report Available: 2-8 days.
- Available STAT?
- No
Billing & Coding
- CPT codes
- 82088
- LOINC
- 1765-7
- Interfaced Order Code
- UOW2297