Hypermagnesemia is a greater-than-normal amount of magnesium in the blood.
Patients with poor renal function or long-term abuse of magnesium-containing
compounds have difficulty excreting magnesium. The excess of magnesium in the
blood causes the cell membranes to become less excitable than normal, requiring
a greater stimuli than would normally be needed to cause a required effect. As the
magnesium level continues to rise, the cell membrane becomes more resistant to
its natural stimuli.
PROGNOSIS
Correction of the magnesium level is necessary to prevent life-threatening com-
plications. Patients are at significant risk for cardiac arrest as the magnesium lev-
els continue to rise.
SIGNS AND SYMPTOMS
• Bradycardia due to slowed cellular response to normal stimuli
• Hypotension due to vasodilation
• Drowsiness or lethargy
• Weakness
• Less-than-normal deep tendon reflexes
• Confusion
• Urinary retention
• Cardiac arrest when level severely elevated
TREATMENT
• Administer magnesium antagonist intravenously:
• calcium chloride
• Administer Loop diuretic to reduce magnesium level:
• furosemide
• Dialysis—hemodialysis or peritoneal, to remove excess magnesium (espe-
cially in patients with renal failure).
• Reduce magnesium in diet (avoid meat, legumes, dark green leafy vegetables,
fish, whole grains, nuts).
• Increase fluid intake to maintain hydration.
NURSING DIAGNOSES
• Impaired gas exchange
• Risk for injury
• Reduced cardiac output
NURSING INTERVENTION
• Monitor intake and output.
• Monitor vital signs for changes.
• Monitor cardiovascular status for changes in heart rate, rhythm.
• Monitor labs for electrolyte balance.
• Explain to the patient:
• Avoid foods high in magnesium.
• Avoid magnesium-based medications.
