Catecholamines, Fractionated, 24 Hour Urine without Creatinine
Also known as: Catecholamines, Free, Adrenaline, Noradrenaline
Use
Measurement of the principal catecholamines — epinephrine, norepinephrine, and dopamine — in a 24‑hour urine collection aids in the evaluation of catecholamine‑secreting tumors such as pheochromocytomas and neuroblastomas, as well as assessing causes of orthostatic hypotension. This test excludes creatinine measurement.
Special Instructions
Specimen requires 24‑hour urine collection preserved with 25 mL of 6 N HCl (to maintain pH ≤ 3). If unpreserved, collection must be refrigerated during collection, shipped frozen, and overall pH must be ≤ 6.
Limitations
Smaller elevations in catecholamines may reflect physiologic stimuli, medications, stress, or improper specimen collection rather than pathology. Accurate results depend on proper preservation and refrigeration during collection. Lack of creatinine normalization may affect interpretation relative to total volume.
Methodology
Mass Spectrometry
Biomarkers
Result Turnaround Time
3-4 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
Not provided
Minimum Volume
0.7 mL
Container
Plastic screw‑top vial
Collection Instructions
Collect 24‑hour urine with 25 mL 6 N HCl to maintain a pH ≤ 3. If no preservative used, specimen must be refrigerated during collection but shipped frozen and pH ≤ 6.
Patient Preparation
Patient should preferably be off medications for three days prior to collection; avoid alcohol, coffee, tea, tobacco, and strenuous exercise.
Causes for Rejection
Preserved urine received refrigerated with pH > 3; unpreserved urine received frozen with pH > 6.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Unacceptable |
| Refrigerated | 30 days |
| Frozen | 60 days |