Test
Name

Magnesium,
24-hour Urine

Test
Code

259

Unit

Mg/24h

Station

Chemistry

Synonym
Name/Abbreviation

Mg,
Urine

CPT
Code

83735

Performing
Facility

American
Medical Labs, Herzliya Pituah

Analyzer

Roche cobas 6000

Test
Method

Spectrophotometry

AML
Preferred Tube

24
Hour Urine Collection

Storage
Instructions

Refrigerated

Min.
Volume

10
mL of well mixed urine from measured 24 hour
collection.

Comments

After
collection, add 6N HCl.

Turn-Around-Time

One day.

Intended
Use

To
check Magnesium balance. Magnesium urinary excretion is enhanced by
increasing blood alcohol levels, diuretics, Bartter syndrome,
corticosteroids, cis-platinum therapy and aldosterone. Renal magnesium
wasting occurs in renal transplant recipients who are on cyclosporine and
prednisone. Renal conservation of magnesium is diminished by
hypercalciuria, salt-losing conditions, and the syndrome of inappropriate
secretion of antidiuretic hormone.
Before and after therapeutic magnesium administration to further
investigate the significance of an apparent low serum
magnesium.

Patient
Preparation

Instruct
the patient to void at 8 AM 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 AM the next morning). Screw the lid on securely.

Reasons
for Rejection

No
HCl preservative added

Adult
Reference Ranges

 60 to 210 mg/24
h