History
Common causes of hypermagnesemia include renal failure and iatrogenic manipulations. [7] However, other diseases may result in increased magnesium; the degree of elevation determines the symptoms. Acute elevations of magnesium usually are more symptomatic than slow rises.
Magnesium levels of 2-4 mEq/L are associated with the following:
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Nausea
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Vomiting
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Skin flushing
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Weakness
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Lightheadedness
High magnesium levels are associated with depressed levels of consciousness, respiratory depression, and cardiac arrest.
Physical Examination
Physical findings are related to the serum magnesium levels.
Serum magnesium levels of 3.5-5 mEq/L are associated with the following:
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Disappearance of deep tendon reflexes
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Muscle weakness
Serum magnesium levels of 5-6 mEq/L are related to the following:
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Hypotension
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Vasodilatation
Serum magnesium levels of 8-10 mEq/L are associated with the following:
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Arrhythmia, including atrial fibrillation
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Intraventricular conduction delay
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Flaccid skeletal muscle paralysis
Levels of serum magnesium greater than 10 mEq/L are related to the following:
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Asystole
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Heart block
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Ventilatory failure
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Stupor or coma
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Death
Elevated levels of magnesium also are associated with the following:
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Delayed thrombin formation
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Platelet clumping