Catecholamines, Plasma (Referred Out) - Saskatoon

Discipline

Biochemistry

Overview

Description

Not recommended for evaluation of pheochromocytoma or paraganglioma. Measurement of plasma or urine fractionated metanephrines provides better diagnostic sensitivity for pheochromocytoma than measurement of catecholamines.
Collect after overnight fast (water and non-caffeinated drinks permissable).
Medications may interfere with catecholamines and metabolites including theophylline, vasodilators, tricyclic antidepressents, monoamine oxidase inhibitors, L-dopa, clonidine, dexamethasone, diuretics, antidiuretic hormone, nicotine, propafenone, alpha methyldopa, alpha-methyl-para-tyrosine, isoproteronal, dobutamine and carbidopa.
Patient must refrain from using tobacco, drinking caffeinated beverages.
Tyrosine rich foods (such as nuts, bananas, or cheese) and alcohol could also affect the results.

Alias

Catecholamine fractionation
Epinephrine, plasma
Norepinephrine, plasma
Dopamine, plasma

Specimen Information

Specimen types accepted

Plasma

Specimen collection container

Preferred Collection Container: Lavender (EDTA) 4.0mL

Required volume

Optimal Volume: 4.0 mL Full collection tube
Minimum Volume: 2 mL plasma

(Submitting the minimum volume makes it impossible to repeat the test or perform confirmatory/reflex testing. In some situations, a minimum volume may require a second collection)

Rejection criteria

Received in laboratory not frozen nor on ice pack more than 30 minutes after collection
If specimen thaws, it is unsuitable for analysis.
Pathology and Laboratory Medicine Acceptance and Rejection Criteria

Testing Information

Clinical interpretation

Result interpretation should be correlated with clinical and other laboratory findings.

Performance

Methodology

Liquid Chromatography/Tandem Mass Spectometry

Days/times performed

Availability	Shipped Mondays and Wednesdays
Testing Site	Referred out by St. Paul’s Hospital Laboratory to Dynacare (Ontario)

Maximum laboratory time

15 day turnaround time by referral laboratory

Other information

Collection Requirements	Patient must be supine for at least 15 minutes prior to and during specimen collection. Specimen for this test must be collected, processed, aliquoted and frozen within 30 minutes of collection. Patient must be referred to a Health Services Centre or a Hospital Test Center for collection. Centrifuge and aliquot plasma to a transport tube. Indicate patient's medications.
Additional Comments	Small increases in catecholamines usually are the result of physiological stimuli, drugs, or improper specimen collection. Elevated catecholamine concentrations are observed in specimens collected from upright or standing adults

Last Updated: October 8, 2024