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TEST ID U24VMAr VMA (VANILLYLMANDELIC ACID), 24-HOUR URINE

Important Note

ORDERING GUIDANCE

In the past, this test has been used to screen for pheochromocytoma. However, vanillylmandelic acid (VMA) is not the analyte of choice to rule out a diagnosis of pheochromocytoma. Recommended tests for that purpose include:

-PMET / Metanephrines, Fractionated, Free, Plasma

-METAF / Metanephrines, Fractionated, 24 Hour, Urine

-CATU / Catecholamine Fractionation, Free, 24 Hour, Urine

 

 

Factors interfering with accuracy of 24hr urine collection:

Failure to collect all urine excreted during the 24 hr time frame.

Going beyond the  24 hr collection period and collecting excess urine.

Losing urine from specimen container through spilling.

Failure to keep urine cold during collection period.

Performing Laboratory

NRLS-Regional Medical Lab

Specimen Type

24 Hour Urine

Specimen Required

Container/Tube:
Preferred: 24 hour urine container, no preservative.
Specimen Volume: Entire collection

Collection Instructions:

To start the 24-hour collection, the patient voids, discards specimen, and notes the date and time on label. *Note:  24 hour urine tests must begin on an empty bladder. All urine for the following 24-hour period is added to the container. Urine must be kept on ice or in a refrigerator.

 Exactly 24  hours from the start time, the patient voids again, adding the specimen to the container, and the date and time is recorded as the end of collection. 

Lab Processing Instructions:

Transfer 4 mL aliquot from a well-mixed 24-hour collection to a standard transport tube.

Record total volume and collection time interval on transport tube.

Specimen Minimum Volume

Full Collection

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated(preferred) 1 week
  Frozen 2 weeks

 

Reference Values

An interpretive report will be provided