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Alternative names Return to top
Norepinephrine - blood; Epinephrine - blood; Adrenalin - blood; Dopamine - bloodDefinition Return to top
This test measures the level of catecholamines in the plasma portion of blood.How the test is performed Return to top
Catecholamines are more often measured with a urine test than with this blood test, although the blood test is sometimes used.
Adult or child:
Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and a tourniquet (an elastic band) or blood pressure cuff is placed around the upper arm to apply pressure and cause veins below the tourniquet to distend (fill with blood).
A needle is inserted into the vein, and the blood is collected in an airtight vial or a syringe. During the procedure, the tourniquet is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
Infant or young child:
The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.
How to prepare for the test Return to top
Certain foods can increase catecholamine levels including coffee, tea, bananas, chocolate, cocoa, citrus fruits, and vanilla. Avoid these foods for several days prior to the test, particularly if both serum and urine catecholamines are to be measured.
Avoid other interfering factors:
Consult your health care provider regarding the need to discontinue potentially interfering drugs. Drugs that can increase catecholamine measurements include caffeine, levodopa, lithium, aminophylline, chloral hydrate, clonidine, disulfiram, erythromycin, insulin, methenamine, methyldopa, nicotinic acid (large doses), quinidine, tetracyclines, and nitroglycerin.
Drugs that can decrease catecholamine measurements include clonidine, disulfiram, guanethidine, imipramine, MAO inhibitors, phenothiazines, salicylates, and reserpine.
Never discontinue any medication without first consulting your health care provider.
Infants and children:
The physical and psychological preparation a parent can provide for this or any test or procedure depends on the child's age, interests, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:
How the test will feel Return to top
When the needle is inserted to draw blood, some people may feel moderate pain, while others may feel only a prick or stinging sensation. Afterward, there may be some throbbing.Why the test is performed Return to top
This test is used primarily to screen for, diagnose, and monitor treatment of pheochromocytoma or neuroblastoma.
Catecholamines are chemically similar small molecules derived from tyrosine, an amino acid. The major catecholamines are dopamine, norepinephrine, and epinephrine (which used to be called adrenalin).
Normal Values Return to top
Epinephrine: 20 ng/100 mL
Norepinephrine: 60 ng/100 mL
Note: ng/mL = nanograms per milliliter
What abnormal results mean Return to top
Elevated levels of blood catecholamines may indicate the following:What the risks are Return to top
Special considerations Return to top
The test's accuracy is affected by several foods and drugs as well as such things as physical activity and stress.
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult from some people than from others.
Update Date: 5/20/2003 Updated by: Bridget Martell, M.D., Department of Internal Medicine, Albert Einstein College of Medicine, New York, NY. Review provided by VeriMed Healthcare Network.
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Page last updated: 28 October 2004 |