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Test Code Mg Magnesium Level

Additional Codes

Cerner

NextGen

Magnesium Level

Magnesium Level

Mg

 

Methodology

Colorimetric (reflectance spectrophotometry).

Patient Preparation

None

Collection Instructions

Standard phlebotomy practices.

Specimen Requirements

Container

Specimen Type

Tube

Lithium Heparin Plasma

PST  or  or 

Serum

 or 

SST

 or  or 

 

Stability

Storage

Temperature

Stability

Room Temperature

18-28°C

≤ 1 week

If separated within 2 hours

Refrigerated

 2-8°C

≤ 1 week

If separated within 2 hours

Frozen

≤-18 °C

≤ 1 month

Rejection Criteria

Gross Hemolysis

Result Reporting and Reference Values

Reported in mg/dL.

Age

Low

High

Critical Low

Critical High

0- 18Y

1.8

2.4

1.2

4.9

18 – 150Y

1.6

2.3

1.2

4.9

Reflex Testing

None

Limitations

  • Ortho reports the following bias:  Calicum at 20mg/dL has a bias of +0.3 mg/dL    
  • Ortho reports no significant effect with the following: 
    • Bilirubin up to 27 mg/dL
    • Lipemia up to 800 mg/dL
  • The following interpretive data is visible to the practitioner: Calcium >20 mg/dl creates a positive bias

Useful For

Magnesium is predominately an intracellular cation and is essential in enzyme reactions. Magnesium deficiency may cause weakness, tremors, tetany, and convulsions. Hypomagnesemia is associated with hypocalcemia, alcoholism, some types of malnutrition, malabsorption, chronic hemodialysis, and pregnancy. Increased serum magnesium concentrations occur with renal failure, dehydration, Addison’s disease, and increased medicinal intake of magnesium, such as in the treatment of preeclampsia (hypertension induced by pregnancy).