Catecholamine Fractionation, Free, Plasma
Use
This test is useful for diagnosing pheochromocytoma and paraganglioma as an auxiliary test to fractionated plasma and urine metanephrine measurements. It is also used for diagnosing follow-up of patients with neuroblastoma and related tumors and for evaluating patients with autonomic dysfunction or failure or autonomic neuropathy.
Special Instructions
This test should have its own collection as sharing the specimen can introduce unforeseen analysis interferences. It is not the first-tier test for pheochromocytoma due to the possibility of plasma catecholamine levels not being continuously elevated. For recommended first-tier tests, consider Metanephrines, Fractionated, Free, Plasma or Metanephrines, Fractionated, 24 Hour, Urine.
Limitations
Plasma catecholamine measurements are useful in some cases but are not recommended as the first-line test for pheochromocytoma. They have a high diagnostic sensitivity if collected during a 'spell,' but the specificity of these cutoffs is low for differentiating tumors from other patients with similar symptoms. There can be significant impact due to improper specimen collection, handling, or the presence of interfering drugs.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 34551-2
- 2666-6
- 2230-1
- 2216-0
Result Turnaround Time
2-9 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
3 mL
Minimum Volume
2 mL
Container
10-mL Catecholamine tubes containing EDTA-sodium metabisulfite solution. Plastic vial for submission.
Collection Instructions
Drawing from an indwelling IV line/catheter/butterfly is required. The patient should rest for 30 minutes in a supine position. Withdraw and discard a minimum of 2 mL of blood to remove saline out of the catheter. Collect 10 mL blood into chilled 10 mL catecholamine tube containing EDTA-sodium metabisulfite solution. Refrigerated centrifuge separation required within 30 minutes, then freeze and transport frozen.
Patient Preparation
Discontinue drugs affecting catecholamine levels for at least one week. Refrain from eating, tobacco, or caffeinated beverages for 4 hours prior.
Storage Instructions
Specimens must remain refrigerated at all times.
Causes for Rejection
Gross hemolysis, lipemia, or icterus are acceptable.
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 28 days |