Catecholamines, Fractionated
Label Mnemonic: CAT24
Epic Lab Code: LAB7452
Downtime Form: A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery
Commercial Mail-out Laboratory
5231 RCP
24 hr Urine More information
Specimen Instructions:
Refrigerate during 24 hr collection in plastic container. Adequate refrigeration is the most important aspect of specimen preservation.

Abstain from medications for 72 hours prior to collection.

All five tests may be done on same collection.
Collection Medium:
Urine - 24 hour/timed plastic urine container
Preferred Minimum: 4 mL from a well-mixed 24 hr urine collection.
Absolute Minimum: 2.5 mL from a well-mixed 24 hr urine collection.
Rejection Criteria:
Room temperature specimens. Specimens preserved with boric acid or acetic acid. Specimens with pH greater than 7.
Turn Around Time:
1-4 days upon receipt at reference laboratory
Reference Range:
Reference Intervals for 24-Hour Calculations (24-Hour Urine)

Components               Reference Interval

    0-3 years            Not Established 
    4-6 years            95-221 μg/d 
    7-12 years           76-371 μg/d 
    13-17 years          137-393 μg/d 
    18-69 years          77-324 μg/d 
    70 years and older   56-272 μg/d 

    0-3 years            Not Established 
    4-17 years           1-9 μg/d 
    18-69 years          1-7 μg/d 
    70 years and older   1-5 μg/d 

    0-3 years            Not Established 
    4-12 years           6-45 μg/d 
    13-17 years          15-57 μg/d 
    18-69 years          16-71 μg/d 
    70 years and older   11-60 μg/d 

Creatinine (24 hr)
    3-8 years            140-700 mg/d
    9-12 years           300-1300 mg/d
    13-17 years          500-2300 mg/d
    18-50 years          1000-2500 mg/d
    51-80 years          800-2100 mg/d
    81 years and older   600-2000 mg/d

    3-8 years            140-700 mg/d
    9-12 years           300-1300 mg/d
    13-17 years          400-1600 mg/d
    18-50 years          700-1600 mg/d
    51-80 years          500-1400 mg/d
    81 years and older   400-1300 mg/d

Reference Intervals for Ratio-to-Creatinine (CRT) Calculations (Random Urine)

    0-11 months          240-1290 μg/g crt
    1-3 years            80-1220 μg/g crt
    4-10 years           220-720 μg/g crt
    11-17 years          120-450 μg/g crt
    18 years and older   0-250 μg/g crt

    0-11 months          0-380 μg/g crt
    1-3 years            0-82 μg/g crt
    4-10 years           5-93 μg/g crt
    11-17 years          3-58 μg/g crt
    18 years and older   0-20 μg/g crt

    0-11 months          25-310 μg/g crt
    1-3 years            25-290 μg/g crt
    4-10 years           27-110 μg/g crt
    11-17 years          4-105 μg/g crt
    18 years and older   0-45 μg/g crt
Interpretive Data:
The optimal specimen for this testing is a 24-hour urine collection. Mass per day calculations are not reported for patients younger than 18 years of age and for the following specimen types: a random collection, a collection with duration of less than 20 hours, a collection with duration of greater than 28 hours, or a collection with total volume less than 400 mL. Ratios to creatinine may be useful for these evaluations.

Smaller increases in catecholamine concentrations (less than two times the upper limit) usually are the result of physiological stimuli, drugs, or improper specimen collection. Significant elevation of one or more catecholamines (three or more times the upper reference limit) is associated with an increased probability of a neuroendocrine tumor.
Secreting neuroendocrine tumors are typically associated with catecholamine concentrations several times higher than the upper reference intervals. Large elevations can be seen in life-threatening illnesses and drug interferences. Common reasons for slight and moderate elevations include intense physical activity, emotional and physical stress, drug interferences, and improper specimen collection.

Medications which may physiologically interfere with catecholamines and metabolites include amphetamines and amphetamine-like compounds, appetite suppressants, bromocriptine, buspirone, caffeine, carbidopa- levodopa (Sinemet®), clonidine, dexamethasone, diuretics (in doses sufficient to deplete sodium), ethanol, isoproterenol, methyldopa (Aldomet®), MAO inhibitors, nicotine, nose drops, propafenone (Rythmol), reserpine, theophylline, tricyclic antidepressants, and vasodilators. The effects of some drugs on catecholamine results may not be predictable.

VMA, Catecholamines and Metanephrines may be done on same collection. Alpha methylodopa (Aldomet) and Labetalol (Normodyne) will falsely elevate the apparent concentration of urine catecholamines. Collection containers available from pharmacy.

Includes: Epidenphrine, Norepinephrine and Dopamine.

If screening for Neuroblastoma, the following tests are suggested: CAT24 (Catecholamines, Fractionated; Dopamine is included), HVA24 (Homovanillic Acid), MET24 (Metanephrines), VMA24 (Vanillylmandelic Acid).
Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
CPT Code:
See also:
Homovanillic Acid, 24 hr Urine
Metanephrines Total, 24 hr Urine
Vanillylmandelic Acid, 24 hr Urine