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Test Code CRAV Cortisol, Right Adrenal Vein, Serum

Reporting Name

Cortisol, RAV

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Testing cortisol levels in the right adrenal vein

 

Second-order testing when cortisol measurement by immunoassay gives results that are not consistent with clinical symptoms, or if patients are known to, or suspected of, taking exogenous synthetic steroids

 

An adjunct in the differential diagnosis of primary and secondary adrenal insufficiency

 

An adjunct in the differential diagnosis of Cushing syndrome

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)


Ordering Guidance


For confirming the presence of synthetic steroids, order SGSS / Synthetic Glucocorticoid Screen, Serum.



Specimen Required


Supplies: Sarstedt Aliquot Tube 5 mL (T914)

Collection Container/Tube: Red top

Specimen Volume: 1.5 mL

Submission Container/Tube: Plastic vial

Collection Instructions:

1. Morning (8 a.m.) and afternoon (4 p.m.) specimens are preferred.

2. Include time of collection.

3. Centrifuge and aliquot serum into a plastic vial.

Additional Information: If multiple specimens are collected, send a separate order for each specimen.


Specimen Type

Serum

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 28 days
  Ambient  28 days
  Frozen  28 days

Reject Due To

Gross hemolysis OK
Gross lipemia Reject
Gross icterus OK

Reference Values

No established reference values

Interpretation

In primary adrenal insufficiency, adrenocorticotropic hormone (ACTH) levels are increased and cortisol levels are decreased; in secondary adrenal insufficiency both ACTH and cortisol levels are decreased.

 

When symptoms of glucocorticoid deficiency are present and the 8 a.m. plasma cortisol value is <10 mcg/dL (or the 24-hour urinary free cortisol value is <50 mcg/24 hours), further studies are needed to establish the diagnosis. The 3 most frequently used tests are the ACTH (cosyntropin) stimulation test, the metyrapone test, and insulin-induced hypoglycemia test. First, the basal plasma ACTH concentration should be measured, and the short cosyntropin stimulation test performed.

 

Cushing syndrome is characterized by increased serum cortisol levels. However, the 24-hour urinary free cortisol excretion is the preferred screening test for Cushing syndrome, specifically CORTU / Cortisol, Free, 24 Hour, Urine that utilizes liquid chromatography-tandem mass spectrometry. A normal result makes the diagnosis unlikely.

 

Symptoms or signs of Cushing syndrome in a patient with low serum and urine cortisol levels suggest possible exogenous synthetic steroid effects.

Day(s) Performed

Monday through Friday

Report Available

2 to 5 days

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

82533

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CRAV Cortisol, RAV 2143-6

 

Result ID Test Result Name Result LOINC Value
6345 Cortisol, RAV 2143-6

Special Instructions