Hypomagnesemia

Background

• HypoK, HypoCa and Hypophos are often also present

Diagnosis

• CNS
  • Muscle weakness
  • Ataxia
  • Confusion
  • Seizures
  • Coma
• GI
  • Dysphagia
• Cardiovascular
  • CHF
  • Dysrhythmias
  • Hypotension
• Miscellaneous
  • Hypokalemia
  • Hypocalcemia
  • Anemia

DDX

1. ETOH
2. Malnutrition
3. Cirrhosis
4. Pancreatitis
5. S/P DKA
6. GI loss (esp diarrhea)
7. Renal wasting
   1. Furosemide
   2. Hypophosphatemia

Treatment

• Replete Magnesium 2gm IV over 2hrs
  • up to 8-12gm may be given on 1st day

• Replete if serum level <1.7
• Usual dose is 2g over 1 hour
• If level <than 1.2, double the dose
• Oral repletion may done if level is >1.2 and pt is asymptomatic
• Magnesium oxide 400mg is approximately equal to 2g of MgSO4

See Also

• Electrolyte Abnormalities (Main)

Source

Tintinalli