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318X CATECHOLAMINES, FRACT, 24 HR URINE
Test CodeCATFRUR
Includes
Epinephrine, Norepinephrine, Calculated Total (E+NE), Dopamine
CPT code 81050 may be added at an additional charge for volume measurement
CPT code 81050 may be added at an additional charge for volume measurement
Preferred Specimen
1 mL preserved 24-hour urine with 25 mL 6N HCl collected in a plastic 24-hour urine container
Patient Preparation
It is preferable for the patient to be off medications for a minimum of 18-24 hours prior to collection. However, common antihypertensives (diuretics, ACE inhibitors, calcium channel blockers, alpha and beta blockers) may cause minimal or no interference.
Patient should avoid tobacco, tea, coffee, and strenuous exercise for 8-12 hours prior to collection.
Minimum Volume
0.7 mL
Other Acceptable Specimens
Unpreserved 24-hour urine with pH ≤6
Instructions
Collect 24-hour urine with 25 mL 6N HCL to maintain a pH ≤3. If no preservative is used, specimen must be stored refrigerated during collection but shipped frozen and pH must be ≤6.
Record 24-hour urine volume and patient's age on test request form and on urine container.
Record 24-hour urine volume and patient's age on test request form and on urine container.
Transport Temperature
Frozen
Specimen Stability
Preserved urine
Room temperature: Unacceptable
Refrigerated: 30 days
Frozen: 60 days
Unpreserved urine
Room temperature: Unacceptable
Refrigerated: 7 days
Frozen: 60 days
Room temperature: Unacceptable
Refrigerated: 30 days
Frozen: 60 days
Unpreserved urine
Room temperature: Unacceptable
Refrigerated: 7 days
Frozen: 60 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Preserved urine received refrigerated with pH >3 • Unpreserved urine received frozen with pH >6
Methodology
Liquid Chromatography/Mass Spectrometry (LC/MS)
Setup Schedule
Set up: Mon-Sat; Report available: 3-5 days
Limitations
Recent surgery, traumatic injury, upright posture, cold, anxiety, pain, clonidine withdrawal, and concurrent acute or chronic illness may produce elevated results.
Clinical Significance
The three catecholamines (norepinephrine, epinephrine and dopamine) are the principal secretory products of neural tissue. Clinically, the measurement of circulating catecholamines is valuable in the diagnosis of catecholamine secreting tumors associated chiefly with hypertension (pheochromocytomas, neuroblastomas and gangliomas) and with the evaluation of orthostatic hypotension.
