From the Guidelines
Hypermagnesemia is a life-threatening condition that requires immediate treatment, typically involving discontinuation of magnesium intake, administration of intravenous fluids, and in severe cases, calcium gluconate to antagonize magnesium's effects, as recommended by the 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1.
Definition and Causes
Hypermagnesemia is defined as a serum magnesium concentration >2.2 mEq/L, with normal ranges between 1.3 to 2.2 mEq/L 1. This condition can occur due to impaired kidney function, excessive magnesium intake through medications or supplements, or iatrogenic overdose, particularly in pregnant women receiving magnesium sulfate 1.
Symptoms and Effects
Symptoms of hypermagnesemia progress from mild to severe and include:
- Muscular weakness
- Paralysis
- Ataxia
- Drowsiness
- Confusion
- Vasodilation
- Hypotension
- Depressed level of consciousness
- Bradycardia
- Cardiac arrhythmias
- Hypoventilation
- Cardiorespiratory arrest 1
Treatment
Treatment of hypermagnesemia involves:
- Discontinuing magnesium intake
- Providing intravenous fluids to enhance renal excretion
- Administering calcium gluconate (1-2 grams IV over 5-10 minutes) to antagonize magnesium's effects, as recommended by the American Heart Association guidelines 1
- Dialysis for life-threatening cases Empirical calcium administration may be lifesaving in cases of iatrogenic overdose, particularly in pregnant women 1.
From the Research
Definition and Causes of Hypermagnesemia
- Hypermagnesemia is a relatively uncommon but potentially life-threatening electrolyte disturbance characterized by elevated magnesium concentrations in the blood 2.
- It can occur in patients with impaired renal function or those receiving magnesium-containing medications or supplements 2, 3.
- Severe hypermagnesemia can also occur in patients with normal renal function, particularly in cases of constipation under MgO or ingestion of magnesium-containing compounds such as Epsom salts 4, 5.
Clinical Outcomes and Management
- Hypermagnesemia has been associated with adverse clinical outcomes, including respiratory and cardiovascular negative outcomes, neuromuscular dysfunction, and coma 2.
- Prompt identification and management of hypermagnesemia are crucial to prevent complications 2.
- Clinical management of hypermagnesemia involves discontinuing magnesium-containing therapies, intravenous fluid therapy, or dialysis in severe cases 2, 5.
- Supportive therapy for hypermagnesemia consists of administration of high-volume fluids, calcium preparation, diuretics, and, in severe cases, hemodialysis 4, 5.
Treatment and Prevention
- Loop diuretics, such as furosemide, may be given as an adjunct to treatment, and their dosage and mode of delivery should be carefully considered 6.
- Preventing hypermagnesemia is crucial, particularly in high-risk populations, such as patients with impaired renal function or those receiving magnesium-containing medications or supplements 2.
- Healthcare providers should monitor serum magnesium concentration in patients at risk of hypermagnesemia and promptly intervene if the concentration exceeds the normal range 2.