Catecholamines, Fractionated, Urine
The bladder must be emptied at the time the collection is to begin, and this urine is discarded. Thereafter all urine must be collected until the end of the scheduled time.
Collect urine with 25 mL of 6N HCl at start of collection to maintain pH between 1 and 3. Refrigerate urine during collection (critical). Mix the collection well before removing aliquot and refrigerate aliquot.
Send a 10.0 mL (minimum) aliquot refrigerated in a screw-capped plastic urine cup. Record total volume on test requisition and specimen label.
*Without preservatives: Not stable at any temperature*
With preservatives: Room Temp 72hrs, Refrigerated 7 days
4-6 days SetUp Mon, Wed, Fri
Evaluate hypertension, especially if paroxysmal; evaluate orthostatic hypotension; diagnose pheochromocytoma; preoperative evaluation of suspected childhood adrenal neoplasms (i.e., neuroblastoma); evaluate possible multiple endocrine adenomatosis. Slightly elevated concentrations (100-200 ug/24 hr) of urinary free catecholamines are consistent with essential hypertension; elevated concentrations (>200 ug/24 hr) are suggestive of pheochromocytoma. Further confirmation of elevated urinary catecholamines can be obtained by determination of urinary metanephrines.