Aldosterone, Urine (Sendout)

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General Information

Lab Name
Aldosterone, Urine
Lab Code
RUALDO
Epic Name
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).

Patient Preparation: If the patient is taking spironolactone (Aldactone), it should be discontinued for 4 to 6 weeks before specimen collection.

Note: Random urine samples are not acceptable for this test. Specimens collected for a duration of <22 hours or >26 hours will be rejected by Mayo and testing will be cancelled.

References
  1. 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, T008, 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: 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
  1. 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

Sample Collection:

  • Preferred: Add 25 mL of 50% acetic acid as a preservative to a timed urine collection container at the start of collection.
    • Use 15 mL of 50% acetic acid for patients <5 years.
    • Preservative is intended to achieve a pH of between approximately 2 and 4.
  • Also Accepted: Boric acid added as preservative prior to collection.
  • Instruct patient to collect specimen for 24 hours.
  • Resource: Mayo Urine Preservatives: Collection and Transport for 24 Hour Urine Specimens.

Mayo Preservative Supply: 50% Acetic Acid, 25 mL [T008]

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.
  • Random samples are not acceptable for this test. Specimens collected for a duration of <22 hours or >26 hours will be rejected by Mayo and testing will be cancelled.
Handling Instructions

Outside Laboratories:

  • Mix sample well and measure the urine volume.
  • Record the total volume and collection interval (required) on the DLMP requisition.
  • Aliquot 10 mL urine into a separate aliquot and refrigerate sample while awaiting shipment. Transport with a cold pack.

Stability: Refrigerated (Preferred): 28 days; Frozen: 28 days; Ambient: 14 days.

Quantity
Requested: 10 mL urine
Minimum: 1 mL urine

Processing

Receiving Instructions

SPS:

  • Mix sample well and measure the urine volume.
  • Record the total volume and collection interval on the requisition.
  • Aliquot 10 mL urine into a screw-cap, plastic urine aliquot tube and refrigerate.

Result-at Entry:

  • RUALDI (Aldosterone Interval): <Enter the collection interval in hours>
  • RUALDV (Aldosterone Volume): <Enter the total volume in mL>

Sendouts:

  • Order Mayo Test: ALDU
  • Interfaced: No

Stability: Refrigerated (Preferred): 28 days; Frozen: 28 days; Ambient: 14 days.

Misc Sendout

Performance

Lab Department
Sendouts Mayo Lab (RF)(MARF)
Frequency
Performed: Tuesday, Thursday. Report Available: 2-8 days.
Available STAT?
No
Performing Location(s)
Sendout Mayo Clinic Laboratories (Superior Drive)
800-533-1710

3050 Superior Drive NW
Rochester, MN 55901

Billing & Coding

CPT Codes
82088
LOINC
1765-7
Interfaced Order Code
UOW2297