Test Code MGOB OB MAGNESIUM LAB3098
Performing Laboratory
UnityPoint The Finley Hospital
Test Method
Colorimetric; Roche cobas Pro
Performance
Testing is performed Monday through Sunday.
Routine: Typically completed within 4 hours after the specimen arrives at the testing site.
STAT: Typically completed within 30 minutes after the specimen arrives at the testing site.
Specimen Requirement
- Lithium heparin plasma (green) is the specimen of choice. 0.5mL
- Serum (red/gold) is also an acceptable sample type.
- Gel tubes are acceptable.
- It is recommended that the serum be separated from contact with cells within 2 hours from time of collection.
- Magnesium specimens are stable for 7 days at 15-25°C, 2 days at 2-8°C, and 1 year at -20°C.
Useful For
Monitoring magnesium in pregnant patients who are receiving magnesium therapy is important to ensure the patient is in a therapeutic range. Magnesium is used for maternal hypertension, neuroprotection for the fetus, and to stop preterm labor.
Reference Values
Therapeutic Range: 5.0-9.0 mg/dL
Critical values: less than (<) 1.0 mg/dL or greater than (>) 9.0 mg/dL
CPT Code Information
83735 Chemistry: Magnesium
LOINC Code Information
19123-9 Magnesium [Mass/Volume] In Serum Or Plasma