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HelpTest Code LAB0202242 Catecholamine Fractionation, Free, 24 Hour, Urine
Additional Codes
| Mayo Test ID |
|---|
| CATU |
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Useful For
An auxiliary test to fractionated plasma and urine metanephrine measurements in the diagnosis of pheochromocytoma and paraganglioma
An auxiliary test to urine vanillylmandelic acid and homovanillic acid determination in the diagnosis and follow-up of patients with neuroblastoma and related tumors
This test is not useful as a first-line test for pheochromocytoma.
Special Instructions
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Catecholamine Fract, Free, USpecimen Type
UrineOrdering Guidance
This assay is of greatest value when the specimen is collected during a hypertensive episode.
Do not perform the test on patients withdrawing from legal or illegal drugs known to cause rebound catecholamine release during withdrawal (see Cautions).
This test is not a first-line test for pheochromocytoma. The recommended first-line laboratory tests for pheochromocytoma are PMET / Metanephrines, Fractionated, Free, Plasma; and METAF / Metanephrines, Fractionated, 24 Hour, Urine.
Necessary Information
24-Hour volume (in milliliters) is required.
Specimen Required
Patient Preparation:
1. If medically feasible, discontinue drugs that release or hinder metabolism of epinephrine, norepinephrine, or dopamine for at least 1 week prior to specimen collection (see Cautions for details). If this is not possible for medical reasons, contact the laboratory to discuss whether a shorter drug-withdrawal period may be acceptable.
2. Unless the reason for testing is drug monitoring, the patient should stop any epinephrine, norepinephrine, or dopamine injections or infusions for at least 12 hours prior to specimen collection.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container: Plastic vial
Specimen Volume: 2 mL
Collection Instructions:
1. Add 25 mL of 50% acetic acid as preservative at start of collection. Use 15 mL of 50% acetic acid for children younger than 5 years old. This preservative is intended to achieve a pH of between approximately 2 and 4.
2. Collect urine for 24 hours.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
Specimen Minimum Volume
1.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 28 days | |
| Frozen | 28 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
Norepinephrine <1 year: <11 mcg/24 h
1 year: 1-17 mcg/24 h
2-3 years: 4-29 mcg/24 h
4-6 years: 8-45 mcg/24 h
7-9 years: 13-65 mcg/24 h
≥10 years: 15-80 mcg/24 h
Epinephrine
<1 year: <2.6 mcg/24 h
1 year: <3.6 mcg/24 h
2-3 years: <6.1 mcg/24 h
4-9 years: 0.2-10.0 mcg/24 h
10-15 years: 0.5-20.0 mcg/24 h
≥16 years: <21 mcg/24 h
Dopamine
<1 year: <86 mcg/24 h
1 year: 10-140 mcg/24 h
2-3 years: 40-260 mcg/24 h
≥4 years: 65-400 mcg/24 h
For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html.
Interpretation
Diagnosis of Pheochromocytoma:
This test should not be used as the first-line test for pheochromocytoma. PMET / Metanephrines, Fractionated, Free, Plasma (the most sensitive assay) and METAF / Metanephrines, Fractionated, 24 Hour, Urine (almost as sensitive and highly specific) are the recommended first-line laboratory tests for pheochromocytoma.
However, urine catecholamine measurements can still be useful in patients whose plasma or urine metanephrine measurements do not completely exclude the diagnosis. In such cases, urine catecholamine specimens have an 86% diagnostic sensitivity when cutoff levels of greater than 80 mg/24 hours for norepinephrine and greater than 20 mg/24 hours for epinephrine are employed. Unfortunately, the specificity of these cutoff levels for separating tumor patients from other patients with similar symptoms is only 88%. When more specific (98%) decision levels of greater than 170 mg/24 hours for norepinephrine or greater than 35 mg/24 hours for epinephrine are used, the assay's sensitivity falls to about 77%.
Diagnosis of Neuroblastoma:
Vanillylmandelic acid, homovanillic acid, and sometimes urine catecholamine measurements using either random urine or 24-hour urine collections are the mainstay of biochemical diagnosis and follow-up of neuroblastoma; 1 or more of these analytes may be elevated.
Day(s) Performed
Monday through Saturday
Report Available
2 to 5 daysSpecimen Retention Time
14 daysTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82384
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CATU | Catecholamine Fract, Free, U | 92938-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| TM48 | Collection Duration (h) | 13362-9 |
| VL46 | Volume (mL) | 3167-4 |
| 2106 | Norepinephrine | 2668-2 |
| 2107 | Epinephrine | 2232-7 |
| 2108 | Dopamine | 2218-6 |
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.