Hypermagnesemia

Hypermagnesemia

• Etiology
  • Defined as serum magnesium > 2.2 mEq/L
    • Not symptomatic until >4
  • PTH release is impaired in Mg >6mg/dl
  • MCC is Renal Failure
    • Caused by real function impairment (decreased excretion) or supplements
    • Flushing with diminished reflexes to flaccid quadriplegia, apnea, and cardiac arrest, rare finding
  • Iatrogenic
    • Laxatives, IV mg treatment for preeclampsia
    • DKA, tumor lysis syndrome, Excessive tissue breakdown
    • Adrenal insufficiency
    • Rhabdomyolysis
• Symptoms
  • Hyporeflexia (first sign)
  • Lethargy, Weakness, Paralysis
  • Facial Parethesias
  • Respiratory failure if the diaphragm is affected
  • Bradycardia, Hypotension, Cardiac Arrest
• Imaging
  • EKG: Prolonged PR, QRS, and QT intervals
  • Complete Heart block or asystole if >15 mEq/dl
• Labs
  • +/- Hypocalcemia
• Treatment
  • Quit mg containing agents
  • Normal Saline and a loop diuretic
  • Calcium gluconate (Cardioprotective)
  • Mechanical Ventilation
  • Dialysis if renal failure