Hypermagnesemia is a rare disorder of generation and transformation, with renal impairment being the primary cause. However, most symptomatic cases of hypermagnesemia are associated with the use of magnesium-containing medications.

bubble_chart Etiology

Primarily in patients with renal insufficiency, reduced urinary magnesium excretion leads to hypermagnesemia. It is occasionally observed during the treatment of eclampsia with magnesium sulfate, where both the mother and infant may develop hypermagnesemia. Early-stage burns, extensive injuries or surgical stress responses, severe extracellular fluid depletion, and severe acidosis can also cause elevated serum magnesium levels.

bubble_chart Clinical Manifestations

Symptoms and signs of magnesium excess typically appear when serum magnesium concentration exceeds 2 mmol/L. The main manifestations include fatigue, lack of strength, loss of tendon reflexes, and decreased blood pressure. When serum magnesium levels rise further, cardiac conduction dysfunction occurs, with electrocardiogram showing prolonged PR intervals, widened QRS complexes, and elevated T waves, similar to the ECG changes seen in hyperkalemia. In advanced stages, respiratory depression, drowsiness, and unconsciousness may occur, and even cardiac arrest can happen.

bubble_chart Treatment Measures

There is a significant antagonistic effect between calcium and magnesium. Intravenous administration of 10% calcium gluconate (10–20 ml) or 10% calcium chloride (5–10 ml) can be given first to counteract magnesium's inhibitory effects on the heart and muscles. At the same time, acidosis and dehydration should be actively corrected. If serum magnesium levels do not decrease or symptoms do not improve, peritoneal dialysis or hemodialysis should be initiated as early as possible.