hypomagnesemia%20-and-%20hypermagnesemia
HYPOMAGNESEMIA & HYPERMAGNESEMIA
Hypomagnesemia is having a serum magnesium concentration of <1.3 mEq/L.
Patients with mild hypomagnesemia is asymptomatic and have usually a serum Mg >0.5 mmol/L. While those with moderate-severe hypomagnesemia, the patient is symptomatic and have serum Mg <5 mmol/L.
Hypermagnesemia signs and symptoms usually do not appear unless Mg >2 mmol/L (5 mg/dL). It rarely occurs and usually iatrogenic.

Definition

  • Hypomagnesemia has a serum magnesium concentration of <1.3 mEq/L
  • Hypermagnesemia has a serum magnesium concentration of >2.2 mEq/L

Etiology

Causes of Hypomagnesemia
Increased Intestinal Losses
  • Vomiting, diarrhea
  • Prolonged nasogastric suction
  • Extensive bowel resection
  • Malabsorption syndromes
  • Severe malnutrition
  • Steatorrhoea
  • Acute pancreatitis
  • Intestinal fistula
  • Ileitis, colitis
Drugs
  • Diuretics
  • Aminoglycosides
  • Cisplatin
  • Alcohol
  • Pentamidine
  • Ciclosporin
  • Amphotericin B
Increased Renal Excretion
  • Volume expansion
  • Hypercalcemia & hypercalciuria
  • Osmotic diuresis
  • Renal disease w/ Mg wasting
  • Renal transplant
Metabolic
  • Diabetes mellitus (DM)
  • Hypoparathyroidism
  • Primary hyperparathyroidism
  • Primary aldosteronism
  • Phosphate depletion
  • Hyperthyroidism
  • Treatment of ketoacidosis
  • Intestinal fistula
  • Hungry bone syndrome

Causes of Hypermagnesemia
Rarely occurs & is usually iatrogenic
  • Patient w/ renal failure receiving Mg-containing antacid, laxative or infusion
  • Untreated ketoacidosis
  • Acute renal failure (ARF) w/ rhabdomyolysis
  • Lithium
  • Volume depletion
  • Familial hypocalciuric hypercalcemia
  • Adrenal insufficiency (AI)
  • Hypothyroidism

Signs and Symptoms

Signs & Symptoms of Hypomagnesemia
Neuromuscular
  • Muscle weakness
  • Ataxia & vertigo
  • Trousseau & Chvostek signs
  • Carpopedal spasm
  • Depression, psychosis
  • Seizures
Cardiovascular
  • Prolonged PR & QT intervals
  • Cardiac arrhythmias
Metabolic
  • Hyperinsulinism
  • Carbohydrate intolerance
  • Atherosclerosis
  • Hypocalcemia
  • Osteoporosis & osteomalacia

Signs & Symptoms of Hypermagnesemia
Neuromuscular
  • Usually do not appear unless Mg >2 mmol/L (5 mg/dL)
  • Hypotension
  • Bradycardia
  • Complete heart block & cardiac arrest
  • ECG abnormalities
  • Drowsiness
  • Depressed respiration & apnea
  • Depressed mental status
  • Disappearance of deep tendon reflexes
  • Muscular weakness
  • Paralysis
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