Cortisol, Inferior Vena Cava, Serum
Use
This test is useful for testing cortisol levels in the inferior vena cava. It is used as a 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. It serves as an adjunct in the differential diagnosis of primary and secondary adrenal insufficiency as well as in Cushing syndrome.
Special Instructions
For confirming the presence of synthetic steroids, order SGSS / Synthetic Glucocorticoid Screen, Serum. Morning (8 a.m.) and afternoon (4 p.m.) specimens are preferred, and the time of collection should be included. Centrifuge and aliquot serum into a plastic vial. If multiple specimens are collected, send a separate order for each specimen.
Limitations
When cortisol assays are used for serial monitoring, the same methodology should be consistent throughout. There is negligible value in an isolated p.m. serum cortisol measurement. Elevated plasma cortisol in women could be falsely indicated due to high estrogen levels resulting in increased corticosteroid-binding globulin, without elevating the free, bioactive cortisol fraction. Multiple factors, including acute stress, certain medications, and alcohol intake can obliterate normal diurnal variations, influencing cortisol responses to suppression and stimulation tests.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 2143-6
- 2143-6
Result Turnaround Time
2-5 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1.5 mL
Minimum Volume
0.5 mL
Container
Red top tube, Plastic vial
Collection Instructions
Morning (8 a.m.) and afternoon (4 p.m.) specimens are preferred. Include time of collection. Centrifuge and aliquot serum into a plastic vial.
Causes for Rejection
Gross lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 28 days |
| Refrigerated | 28 days |
| Frozen | 28 days |