VMA - Specimen: Vanillylmandelic Acid (VMA), 24 Hour, Urine

Test Catalog

Test Name

Test ID: VMA    
Vanillylmandelic Acid (VMA), 24 Hour, Urine

Specimen Type Describes the specimen type validated for testing

Urine

Advisory Information

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

Necessary Information

1. Patients age is required.

2. Collection duration and urine volume are required.

3. All patients receiving L-dopa should be identified to the laboratory when vanillylmandelic acid (VMA) and homovanillic acid (HVA) tests are ordered.

4. Bactrim may interfere with detection of the analyte. All patients taking Bactrim should be identified to the laboratory when VMA and HVA tests are ordered.

Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.

Patient Preparation: Administration of L-dopa may falsely-increase vanillylmandelic acid results; it should be discontinued 24 hours prior to and during collection of specimen.

Supplies: Urine Tubes, 10 mL (T068)

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a 24-hour urine specimen.

2. Add 25 mL of 50% acetic acid as preservative at the start of collection. If specimen is refrigerated during collection, preservative may be added up to 12 hours after collection. Use 15 mL of 50% acetic acid for children <5 years old. This preservative is intended to achieve a pH of between approximately 1 and 5. If necessary, adjust urine pH to 1 to 5 with 50% acetic or HCl acid.

Additional Information: See Urine Preservatives in Special Instructions for multiple collections.

Forms

If not ordering electronically, complete, print, and send an Oncology Test Request Form (T729) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/oncology-request-form.pdf)

Urine Preservative Collection Options

Ambient

No

Refrigerated

No

Frozen

No

6N HCl

Yes

50% Acetic Acid

Preferred

Na2CO3

No

Toluene

No

6N HNO3

Yes

Boric Acid

Yes* (pH must be <5)

Thymol

No

*If boric acid is used, note on specimen container. Also, verify that pH is in desired range (pH=1-5). If pH is outside of desired range, adjust pH with a stronger acid (acetic acid is preferred but other acids listed above could be used if available) in a dropwise fashion to bring pH into desired range.

Specimen Minimum Volume The amount of sample necessary to provide a clinically relevant result as determined by the Laboratory.

2 mL

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

NA

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperatures are also included.

Specimen TypeTemperatureTime
UrineRefrigerated (preferred)28 days
 Frozen 180 days