Application: Detection of hypomagnesemia as the cause of unexplained cardiac arrhythmias, neuromuscular disorders, refractory hypocalcemia. Monitoring magnesium sulfate anticonvulsant therapy or therapy causing renal magnesium loss.
Explanation: Decreased levels may be due to increased renal or gastrointestinal loss, or to decreased intake. Levels fall rapidly in response to reduced intake and may not reflect tissue levels. Increased levels are usually due to renal failure. Patients with clinical features suggesting hypocalcemia and a normal plasma calcium should have plasma magnesium measured.
Specimen: 5 ml blood in red-top tube.
Reference Interval:
1.3-2.1 mEq/L (Adult)
1.4-1.7 mEq/L (Child)
1.4-2.0 mEq/L (Neonate)
