Test Code LABYDEXAM Dexamethasone, Serum
Additional Codes
YDEXAM
Ordering Guidance
To detect the metabolite of fluticasone or Flonase, order 17BFP / Fluticasone 17-Beta-Carboxylic Acid, Random, Urine.
For synthetic glucocorticoid analyte screen, order SGSS / Synthetic Glucocorticoid Screen, Serum.
Specimen Required
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 2 mL
Collection Instructions:
1. Draw blood between 7:30 a.m. and 9:00 a.m. the morning following an evening dose.
2. Centrifuge and aliquot serum into plastic vial within one hour of collection and freeze immediately.
Useful For
Confirming the presence of dexamethasone in serum
Confirming the cause of secondary adrenal insufficiency
This test is not useful as the sole basis for a diagnosis or treatment decisions.
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Dexamethasone, SSpecimen Type
SerumSpecimen Minimum Volume
0.6 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Frozen (preferred) | 28 days | |
Refrigerated | 7 days | ||
Ambient | 72 hours |
Reject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Clinical Information
Synthetic glucocorticoids are widely used and have an important clinical utility both as antiinflammatory and immunosuppressive agents. The medical use of these agents, as well as their surreptitious use, can sometimes lead to a confusing clinical presentation. Patients exposed to these steroids may present with clinical features of Cushing syndrome but with suppressed cortisol levels and evidence of hypothalamus-pituitary-adrenal axis suppression.
Reference Values
Baseline: <30 ng/dL
8:00 a.m. following 1 mg Dexamethasone, previous evening: >100 ng/dL
8:00 a.m. following 8 mg Dexamethasone, (4 x 2 mg doses) previous day: >800 ng/dL
Interpretation
This test will screen for, and quantitate if present, the synthetic glucocorticoid, dexamethasone.
The presence of this synthetic glucocorticoid in serum indicates the current or recent use of this compound.
Cautions
Lack of detection does not preclude use of dexamethasone because adrenal suppression may persist for some time after the exogenous steroid is discontinued.
Method Description
Dexamethasone is extracted from serum and measured by liquid chromatography (high-resolution accurate-mass) mass spectrometry.(Unpublished Mayo method)
Day(s) Performed
Tuesday, Thursday
Report Available
2 to 6 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest 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
80299
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
DEXA | Dexamethasone, S | 14062-4 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
609439 | Dexamethasone, S | 14062-4 |
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.