80 mL aliquot of 24 hour urine collection preserved with Sulfamic acid. Refer to charts in Specimen Handling and Additional Information sections.
If Sulfamic acid is not available, HCl is also an acceptable preservative. See HCl for Urine Preservation.

If test is ordered at the same time as Oxalate, collect with HCl instead of Sulfamic acid. See Oxalate.

Refrigerate during collection.
24 hour urine specimen collection container must have preservative pouch(es) added prior to collection.

Specimen Handling

Collection type	Weight of Sulfamic acid in pouch
24 hour collections for newborn up to 4 years	See Pediatric 24 Hour Urine Acidification chart below
24 hour and timed collections for patients > 4 years	7 g pouch in each 4 liter container collection
Random collections, available for pediatric (<16) patients only	No preservative. Transport to DSC on ice. DSC Accession: freeze specimen upon arrival at DSC.

24 Hour Collections:

Acidify specimen in original collection container.

Record 24 hour volume and collection (start and end ) dates and time in space provided on requisition.
Mix well and pour off acidified aliquot.
Sample pH should be less than 3.0.

Pediatric 24 Hour Urine Acidification:

Age

Number of 0.5 g pouches of Sulfamic acid
to add when Acidifying During Collection

Up to 1 month

Not suitable for 0.5 g pouch
Refer patient to ACH

1 up to 2 months

2

2 up to 4 months

3

4 up to 12 months

4

12 months up to 4 years

5

Additional Information

Testing includes Normetanephrine and Metanephrine

False positive increases in urine and plasma metanephrines and catecholamines have been associated with the following drugs or classes of drugs: anti-depressants, anti-psychotics, some beta blockers, dihydropyridine calcium channel blockers, some anxiolytics, anti-Parkinson’s drugs, decongestants, phenoxybenzamine.

Interpretation of results while on one of these agents should be interpreted with caution and put into clinical context.

24 Hour Urine HVA and VMA have historically been used in the screening of pheochromocytoma and have been replaced by the 24 hour Urine Metanephrine screen, a more specific assay.

Testing Location

Analytical Toxicology

Testing Frequency

Weekly

Alternate Name(s)

Hypertension Screen, Normetanephrine, Pheochromocytoma Screen

Reference Interval

24 hour urine levels less than 2.4 umol/d Metanephrine and less than 5.3 umol/d Normetanephrine may be seen in hypertensive patients.

Age	Sex	Normetanephrine (umol/d)	Random Normetanephrine (umol/mol Ur Creat)	Metanephrine (umol/d)	Random Metanephrine (umol/mol Ur Creat)
0-2 years		Not Available	75-584	Not Available	47-240
3-8 years	M	0.2-0.9	57-443	0.2-0.5	37-191
	F	0.2-0.8	57-443	0.1-0.7	37-191
9-12 years	M	0.5-2.3	33-255	0.3-1.0	24-120
	F	0.3-1.5	33-255	0.2-0.6	24-120
13-17 years	M	0.5-2.5	23-176	0.4-1.1	17-88
	F	0.3-1.6	23-176	0.2-0.9	17-88
> 18 years	M			0.2-1.3
	F			0.2-0.9
18-29 years	M/F	0.6-2.1
30-39 years	M/F	0.6-2.3
40-49 years	M/F	0.6-2.5
50-59 years	M/F	0.7-2.6
60-69 years	M/F	0.8-2.8
> 70 years	M/F	0.8-3.1