Renal System >
Hypomagnesaemia
“Electrolyte disturbance caused by serum magnesium levels less than 0.7mmol/L“
Risk Factors
- Alcoholism
- Congestive heart failure
- Diabetes
- Chronic diarrhoea
- Hypokalaemia
- Hypocalcaemia
- Malnutrition
Aetiology
- Decreased GI absorption:
- Diarrhoea
- Malabsorption
- Inadequate dietary intake
- Increased renal loss
- Diuresis secondary to alcohol
- Glycosuria
- Loop diuretic
Pathophysiology
- Decreased gastrointestinal absorption, increased renal loss of magnesium
Clinical Presentation
- Anorexia
- Nausea & vomiting
- Lethargy
- Weakness
- Personality change
- Tetany (positive Trousseau sign or Chvostek sign)
- Tremor and muscle fasciculations
Investigations
- Measurement of serum magnesium concentration in patients with risk factors and unexplained hypocalcaemia or hypokalaemia
- ECG
Management
- Oral magnesium salts such as magnesium gluconate
- IV or IM magnesium sulfate if severe (<0.5mmol/L) or cannot tolerate oral treatment
Complications
- Cardiac arrhythmia
- Seizures
- Coronary artery vasospasm