Catecholamines, Fractionated, Random Urine (5244)
Use
Measurement of fractionated catecholamines (norepinephrine, epinephrine, dopamine) in a random urine specimen serves as an initial screen or assessment for catecholamine-secreting neuroendocrine tumors such as pheochromocytoma and neuroblastoma. Comparing individual catecholamine excretion relative to creatinine may help normalize variable urine concentration and refine interpretation.
Special Instructions
Patient preparation includes avoiding medications (e.g., antihypertensives) for approximately three days and abstaining from alcohol, caffeine, tobacco, and strenuous activity prior to collection. Random urine collection may require pH adjustment with 6N HCl to maintain pH below 3; if pH ≤6 and sample is frozen, preservative may be omitted. Transport is acceptable at ambient, refrigerated, or frozen conditions with specified stability times.
Limitations
Random urine collections may yield results less reliable than 24‑hour urine due to variability in excretion and collection duration. Analytical interference may arise from medications and physiological factors; modest elevations (less than two-fold) are often due to non‑pathologic causes, while significant elevations (three‑fold or greater) raise suspicion for neuroendocrine tumors. Reference ranges and calculations vary with age.
Methodology
Mass Spectrometry
Biomarkers
Result Turnaround Time
5-7 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
10 mL
Minimum Volume
5 mL
Container
Sterile container; adjust with 6N HCl if needed
Collection Instructions
Random urine; patient off interfering medications for ~3 days; avoid alcohol, caffeine, tobacco, strenuous exercise; add 6N HCl to maintain pH <3; unpreserved acceptable if pH ≤6 and frozen;
Patient Preparation
Avoid medications for ~3 days prior; avoid alcohol, coffee, tea, tobacco, exercise.
Storage Instructions
Ambient okay, refrigerated okay, frozen okay; see stability.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 30 days |
| Frozen | 49 days |