Plastic container with 25 mL of 50% glacial acetic acid (15 mL for pediatric patients) as preservative (preferred). Container available from MLabs. (Specimen with no preservative will be accepted.)
20 mL aliquot of 24 hour urine collection
20 mL aliquot of 24 hour urine collection
Collect 24 hour urine specimen. Add 25 mL of 50% glacial acetic acid (15 mL for pediatric patients) to container prior to start of collection. Following collection, mix well, measure 24 hour urine volume, aliquot 20 mL into a plastic urine container and refrigerate. Record total 24 hour urine volume and collection dates/times on request form. Specimens with no preservative are also acceptable: add 50% glacial acetic acid to container following collection, mix well and send 20 mL aliquot (preferred); alternatively a non-acidified aliquot will be accepted. Patient must be off Aldomet (alpha methyldopa) and its derivatives for a period of not less than 5 weeks. This drug will falsely elevate the metanephrines and normetanephrines. A 12 hr overnight collection will be accepted, but reference ranges have been established only for 24 hr collections.
Patient Preparation: Patient must be off Aldomet (alpha methyldopa) and its derivatives for a period of not less than 5 weeks. This drug will falsely elevate the metanephrines and normetanephrines. A 12 hour overnight collection will be accepted, but reference ranges have been established only for 24 hour collections. 24 hour urine collection: Instruct the patient to void at 8:00am and discard the specimen. Then collect all urine including the final specimen voided at the end of the 24 hour collection period, i.e., 8:00am the next morning. Refrigerate during collection. Screw the lid on securely. Container MUST be labeled with date and time collection started and finished. Transport the specimen promptly to the laboratory. Any test requiring a 24 hour urine collection with 50% glacial acetic acid preservative may also be run on this specimen.
Monday
5 hours
Liquid Chromatography - Tandem Mass Spectrometry (LC-MS/MS)
Metanephrines: 0 - 300 mcg/24 hrs Normetanephrines: 50 - 800 mcg/24 hrs
Evaluate presence of abnormal catecholamine production, may be elevated when VMA and catecholamines are within normal limits. Useful in the diagnosis of pheochromocytoma, neuroblastoma, ganglioneuroblastoma, and hypertension.
Patient must be off Aldomet (alpha methyldopa) and its derivatives for a period of not less than 5 weeks prior to testing. This drug will falsely elevate the metanephrines and normetanephrines.
Coma, recent surgery, severe burns, and recent AMI will give falsely elevated values. There are no dietary restrictions BUT alcohol and nicotine in high doses and unusually high intake of coffee will acutely stimulate the adrenal medulla and may raise the metanephrines and normetanephrines to suspicious levels. Tested using a laboratory developed assay performed on a Waters liquid chromatography tandem mass spectrometry (LC-MS/MS) system. Results determined from different manufacturers and/or methods may not be comparable.
51993-4
83835
36903
May be collected in plain (no preservative) container and acid added at the end of collection. It is preferred to have acid added as soon as possible at the client site, mixed, and an aliquot sent. A non-acidified aliquot may also be sent. [rev 9/08]