Catecholamines, Fractionated, Plasma
| Catecholamines, Fractionated, Plasma | | | |
| Number | | 084152 |
| CPT | | 82384 |
| Synonyms | | Adrenalin®, Plasma ; Dopamine, Plasma ; Epinephrine, Plasma ; Noradrenaline, Plasma ; Norepinephrine, Plasma ; Plasma Catecholamines |
| Test Includes | | Plasma catecholamines, total and fractionated (dopamine, epinephrine, norepinephrine) |
| Specimen | | Plasma, frozen |
Volume | | 3 mL |
| Minimum Volume | | 1.2 mL |
| Container | | Lavender-top (EDTA) tube or green-top (heparin) tube |
| Collection | | Draw blood in lavender-top (EDTA) tube or green-top (heparin) tube. Invert to mix with preservatives. Centrifuge and transfer the plasma to labeled plastic transport tube. Freeze immediately (within 1 hour after collection) at -20°C and ship frozen. The time between blood collection and the preparation of plasma is quite critical; if the time exceeds 1 hour, catecholamine values increase (when blood is kept at 4°C) or decrease (when left at 20°C).1 To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested. |
| Storage Instructions | | Freeze |
| Patient Preparation | | Patient should be fasting for 4 or more hours without smoking. Walnuts, bananas, and alpha methyldopa (Aldomet®) should be avoided for a week prior to sampling. Other drug interference may occur, including epinephrine and epinephrine-like drugs (eg, nosedrops, sinus and cough preparations, bronchodilators, appetite suppressants). Test is unreliable in subjects on levodopa or methenamine mandelate. See the Interfering Substances Appendix for additional interferences. Avoid patient stress.2 See Limitations. An indwelling heparinized venous catheter is advocated, since venipuncture can cause an increase in the substances for which testing is being done. Patient should remain supine in quiet surroundings for at least 30 minutes. |
| Causes for Rejection | | Specimen not drawn in correct tube; plasma not received frozen; inadequate patient preparation |
| Reference Interval | | Adults: - Total: <643 pg/mL
- Epinephrine: <100 pg/mL
- Norepinephrine: <400 pg/mL
- Dopamine: <143 pg/mL
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| Use | | Diagnose pheochromocytoma and those paragangliomas which may secrete epinephrine, norepinephrine, or both. Such tumors may cause paroxysmal or persistent hypertension. Investigation of hypertensive patients, especially younger individuals, particularly when hypertension is paroxysmal, suggesting pheochromocytoma. Plasma catecholamines with urinary metanephrines and VMA are a recommended test battery for pheochromocytoma.3 Others recommend plasma catecholamines when urinary collections are not diagnostic. Work up multiple endocrine adenomatosis, type II. Used also in diagnosis of disorders related to the nervous system and in assessment of resuscitation.4 |
| Limitations | | Plasma levels are useful if elevated, especially during or immediately following an episode of hypertension, but false-negatives occur when the specimen is drawn during an uneventful period. Normotensive pheochromocytoma has been reported.5 False-positive results are common. Epinephrine secretion increases in response to cold and hypoglycemia. Drugs which may affect plasma norepinephrine levels include alpha and beta adrenergic blockers, vasodilators, clonidine, bromocriptine, theophylline, phenothiazine, tricyclic antidepressants, labetalol, calcium channel blockers, converting enzyme inhibitors, bromocriptine, chlorpromazine, haloperidol, and cocaine. Plasma catecholamines are less sensitive than are urinary catecholamines.6 |
| Methodology | | High-pressure liquid chromatography (HPLC) with electrochemical (EC) detection |
| Additional Information | | The adrenal medullary catecholamines (epinephrine, norepinephrine, and their precursor, dopamine) are rapidly metabolized materials with intense vasoactivity, among many other properties. They can be synthesized by extra-adrenal cells or neoplasms of the APUD system. They are pathogenic in the episodic hypertension of pheochromocytoma, and will be elevated during and immediately after such a paroxysm. However, levels may be normal during asymptomatic intervals. Urine catecholamines, metanephrines, VMA, and HVA provide additive information. A clonidine-suppression test has been described; failure to suppress plasma catecholamines with clonidine supports the diagnosis.7,8,9 |
| Footnotes | | - Boomsma F, Alberts G, van Eijk L, et al, “Optimal Collection and Storage Conditions for Catecholamine Measurements in Human Plasma and Urine,” Clin Chem, 1993, 39(12):2503-8.
- Sheps SG, Jiang N-S, Klee GG, et al, “Recent Developments in the Diagnosis and Treatment of Pheochromocytoma,” Mayo Clin Proc, 1990, 65(1):88-95.
- Knight JA and Wu JT, “Catecholamines and Their Metabolites: Clinical and Laboratory Aspects,” Lab Med, 1987, 18:153-8.
- D'Alesandro MM, Reed HL, Robertson R, et al, “Simplified Method of Collecting and Processing Whole Blood for Quantitation of Plasma Catecholamines,” Lab Med, 1990, 26-9.
- Feldman JM, Blalock JA, Zern RT, et al, “Deficiency of Dopamine-β-hydroxylase. A New Mechanism for Normotensive Pheochromocytomas,” Am J Clin Pathol, 1979, 72(2):175-85.
- Rumley A, “The In Vitro Stability of Catecholamines in Whole Blood,” Ann Clin Biochem, 1988, 25(Pt 5):565-86.
- Bravo EL, Tarazi RC, Fouad FM, et al, “Clonidine-Suppression Test: A Useful Aid in the Diagnosis of Pheochromocytoma,” N Engl J Med, 1981, 305(11):623-6.
- Landsberg L and Young JB, “Pheochromocytoma,” Harrison's Principles of Internal Medicine, Braunwald E, Isselbacher KJ, Petersdorf RG, et al, eds, New York, NY: McGraw-Hill Book Co, 1987, 1775-8.
- Bravo EL and Gifford RW Jr, “Current Concepts. Pheochromocytoma: Diagnosis, Localization, and Management,” N Engl J Med, 1984, 311(20):1298-303 (review)
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