Hypokalaemia

Causes

Appropriate Tests

 

Review clinical features; Electrolytes.

Creatinine, Urea.

Sodium urine, Potassium urine, Chloride urine, pH urine may be indicated to differentiate gastrointestinal from renal potassium loss.

Inappropriate fluid and electrolyte replacement

 

Potassium-poor IV fluids

 

Gastrointestinal fluid loss

 

Vomiting

 

Diarrhoea

 

Laxative abuse

Measurement of specific drugs if surreptitious ingestion suspected - consult pathologist.

Fistulae

 

Renal potassium loss

 

Metabolic alkalosis

See under Alkalosis.

Potassium losing diuretics, especially

  • Frusemide
  • Thiazides

Measurement of specific drugs if surreptitious ingestion suspected - consult pathologist.

Osmotic diuresis, especially

  • Diabetic ketoacidosis

 

See under Diabetes mellitus.

Mineralocorticoid excess, including

  • Hyperaldosteronism
  • Cushing's syndrome

 

Renal tubular disorders

 

Magnesium depletion

Magnesium; Magnesium urine. See under Hypomagnesaemia.

Bartter's syndrome

 

Intracellular shift

 

Alkalosis

 

Hypokalaemic periodic paralysis

 

Drugs, especially

  • Beta agonists
  • Theophylline
  • Amphotericin B
  • Ticarcillin/Clavulanate