CATECHOLAMINES PLASMA

Code
900.0925
Name
CATECHOLAMINES PLASMA
Category
None
Department
Send-Out
Start Date
Expiration Date
Synonyms
Adrenaline; epinephrine
CPT Codes
82384
Site
SBMF
Reference Test
44012
ATLAS Test Code

CATECH P

Specimen Information

Type

Green top (heparin) tube

Volume

4.0 ml

Transport Info

Centrifuge and immediately transfer plasma to separate plastic tube Frozen CRITICAL FROZEN – Separate samples must be submitted when multiple tests are ordered

Fasting Required?
False
Patient Instructions

Patient should be calm and in a supine position for 30 minutes prior to collection

Reference Range

See Report

Methodology

Quantitative High Performance Liquid Chromatography (HPLC)

Clinical Significance

Diagnosis of biogenic amine-secreting tumors. The measurement of catecholamines in biological fluids ("biogenic amines") is routinely performed for the diagnosis of biogenic amine-secreting tumors (i.e., pheochromocytoma, neuroblastoma). Biochemical confirmation of excessive catecholamine production is an aid to definitive diagnosis. Pheochromocytoma, a tumor of the chromaffin tissue, is associated with the presence of greatly increased plasma and urinary catecholamine concentrations. Elevated catecholamines have also been found in patients with other tumors of neural tube origin, such as neuroblastomas and ganglioneuroblastomas. Degradation products of catecholamines, normetanephrine, metanephrine, and vanillylmandelic acid (VMA) may be measured in conjunction with the catecholamines. These compounds are present in the urine in much larger quantities than epinephrine, norepinephrine, or dopamine. Large elevations in urine catecholamines can also be seen in life threatening illnesses and drug interferences, although the effects of drugs on catecholamine results may not be predictable. Medications associated with assay interference include: • Alpha-methyldopa (Aldomet): Interferes with quantification of dopamine. • Isoetharine, Isoproterenol, Labetalol: Plasma catecholamines cannot be quantified in patients on these medications. • Monoamine Oxidase (MAO) Inhibitors: Affect physiological levels of catecholamines and their metabolites. • Others: Amphetamines and amphetamine-like compounds, appetite suppressants, bromocriptine, buspirone, caffeine, carbidopa-levodopa (Sinemet), clonidine, dexamethasone, diuretics (in doses sufficient to deplete sodium), ethanol, nicotine, nose drops, propafenone (Rythmol), reserpine, theophylline, tricyclic antidepressants, and vasodilators. Additional causes of elevated catecholamines include improper collection of specimens, anxiety, intense physical activity, and neuroendocrine tumors. Norepinephrine values up to 2000 pg/mL have been observed occasionally in patients with essential hypertension. Conversely, normal plasma catecholamine values have been reported in some patients with pheochromocytoma. Therefore, plasma catecholamine results should be supplemented with additional analytical data for the differential diagnosis of pheochromocytoma/neuroblastoma (e.g., clonidine suppression test, imaging studies, etc.). For optimum results in the collection of plasma catecholamines, the patient should be supine with venous catheter in place for 30 minutes prior to collection. For plasma catecholamines, "upright" ranges typically show epinephrine up to 900 pg/mL, norepinephrine up to 700 pg/mL, and dopamine essentially unchanged. Children, particularly those under 2 years of age, often show an elevated catecholamine response to stress.

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