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Catecholamines - blood
Definition
Catecholamines are hormones produced by the adrenal glands, which are found on top of the kidneys. They are released into the blood during times of physical or emotional stress. The major catecholamines are dopamine, norepinephrine, and epinephrine (which used to be called adrenalin).
This article discusses the test to check the level of catecholamines in a sample of blood.
Catecholamines are more often measured with a urine test than with a blood test. See: Catecholamines - urine
Alternative Names
Norepinephrine - blood; Epinephrine - blood; Adrenalin - blood; Dopamine - blood
How the Test is Performed
Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.
Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.
Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.
How to Prepare for the Test
The accuracy of the test can be affected by certain foods and drugs, as well as physical activity and stress.
Foods that can increase catecholamine levels include:
- Coffee
- Tea
- Bananas
- Chocolate
- Cocoa
- Citrus fruits
- Vanilla
You should avoid these foods for several days prior to the test, particularly if both blood and urine catecholamines are to be measured.
You should also avoid stressful situations and vigorous exercise, which can both interfere with test results.
Drugs that can increase catecholamine measurements include:
- Aminophylline
- Caffeine
- Chloral hydrate
- Clonidine
- Disulfiram
- Erythromycin
- Insulin
- Levodopa
- Lithium
- Methenamine
- Methyldopa
- Nicotinic acid (large doses)
- Nitroglycerin
- Quinidine
- Tetracycline
Drugs that can decrease catecholamine measurements include:
- Clonidine
- Disulfiram
- Guanethidine
- Imipramine
- MAO inhibitors
- Phenothiazines
- Reserpine
- Salicylates
Never stop taking any medication without first talking to your doctor.
How the Test Will Feel
Some people feel discomfort when the needle is inserted. Others may notice only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the Test is Performed
This test is used to diagnose or rule out a pheochromocytoma or neuroblastoma. It may also be done in patients with those conditions to determine if treatment is working.
Normal Results
Epinephrine: 0-900 picograms/milliliter (pg/ml)
Norepinephrine: 0-600 pg/ml
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.
What Abnormal Results Mean
Higher-than-normal levels of blood catecholamines may suggest:
- Acute anxiety
- Ganglioblastoma (very rare)
- Ganglioneuroma (very rare)
- Neuroblastoma (rare)
- Pheochromocytoma (rare)
- Severe stress
Additional conditions under which the test may be performed include Shy-Drager syndrome.
Risks
There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
References
Young WF Jr. Adrenal medulla, catecholamines, and pheochromocytoma. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 246.
Guber HA, Farag AF, Lo J, Sharp J. Evaluation of endocrine function. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. Philadelphia, Pa: Saunders Elsevier; 2006:chap 24.
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
