Aldosterone, Inferior Vena Cava, Plasma
Use
This test is used for the investigation of primary aldosteronism, such as adrenal adenoma, carcinoma, and adrenal cortical hyperplasia, and for secondary aldosteronism related to conditions like renovascular disease, salt depletion, potassium loading, cardiac failure with ascites, pregnancy, and Bartter syndrome. The test analyzes the concentration of aldosterone in the plasma of the inferior vena cava, providing diagnostic insight into mineralocorticoid-related disorders.
Special Instructions
It's essential to discontinue spironolactone (Aldactone) for 4 to 6 weeks before specimen collection, as plasma renin activity cannot be interpreted if the patient is on spironolactone. The recommended collection time is 8 a.m., after the patient has been active for about 2 hours, and the specimen should be collected as close to this time as possible, no later than 10 a.m.
Limitations
Late afternoon levels can be up to 30% lower than early morning levels. Supine positional specimens will present with lower plasma aldosterone levels on average by 50% compared to upright collections. In sodium-depleted subjects, plasma aldosterone levels may show significantly elevated results, sometimes several folds higher than the upper threshold of salt replete upright reference range. Patients on ACE inhibitors may have falsely elevated plasma renin activity, affecting the interpretation of results.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 1763-2
- 1763-2
Result Turnaround Time
2-5 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1.6 mL
Minimum Volume
1 mL
Container
Lavender top (EDTA) tube; plastic vial for submission
Collection Instructions
1. See detailed Renin-Aldosterone Studies guide. 2. Collect the specimen at 8 a.m. after 2 hours of activity, but no later than 10 a.m. 3. Centrifuge and aliquot plasma into a plastic vial.
Patient Preparation
Discontinue spironolactone (Aldactone) for 4 to 6 weeks before specimen collection.
Causes for Rejection
None, as gross hemolysis, lipemia, and icterus are acceptable.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 28 days |
| Frozen | 30 days |