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HelpOrder Code LABFDXM Dexamethasone, Serum
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 |
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
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is extracted from serum and measured by liquid chromatography (high-resolution accurate-mass) mass spectrometry.(Unpublished Mayo method)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
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
80299
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.