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AKA: hypokalaemia, hypopotassemia, hypopotassaemia

Evaluation and management of low blood potassium in pediatric patients


Kidney potassium loss

  • Excess mineralocorticoid activity
    • Mineralocorticoid disorder
    • Renal artery stenosis
    • Liddle syndrome
  • Potassium-wasting diuretics
    • Loop diuretics
    • Thiazide diuretics
  • Tubulopathy
    • Bartter syndrome, Gitelman syndrome
    • Fanconi syndrome
    • Potassium wasting due to hypomagnesemia

Gastrointestinal (GI) potassium loss

  • Diarrhea
    • Laxative abuse
  • Vomiting
    • Nasogastric/orogastric (NG/OG) suction

Intracellular shifts (movement of potassium into cells)

  • Alkalosis
  • Insulin
  • β-agonists (e.g., albuterol)
  • Hypokalemic periodic paralysis (AKA: PP, hypoKPP, hypoPP)

Signs and symptoms

  • Usually asymptomatic
  • Muscle cramps, weakness
  • Cardiac arrhythmias (esp., ventricular tachycardia, ventricular fibrillation)
  • Can decrease ability to concentrate urine


  • If hypertension present, consider evaluation for mineralocorticoid disorder, renal artery stenosis, Liddle’s syndrome, etc.
  • Laboratory workup:
    • Evaluate for other electrolyte derangements, esp. hypomagnesemia
    • Alkalosis
  • EKG if severe (consider if <2.5 mEq/L, esp. if <2 mEq/L)


  • Treat underlying cause
  • Oral potassium chloride replacement is easiest and safest for mild hypokalemia (3-3.5 mEq/L)
  • IV repletion for severe/symptomatic or if unable to tolerate PO