Hypokalaemia

Data gathering

  • Assess severity
    • mild 3.1 – 3.4
    • moderate 2.6 – 3.0
    • severe <2.5
  • Assess if cardiac symptoms
  • Assess whether high risk – elderly, digoxin, heart failure, IHD, LVH, arrhythmia
  • Consider causes
    • Spurious – storage at high temperatures, very high WCC
    • Magnesium depletion
    • Poor nutritional status – anorexia, alcoholism, malabsorption, chronic D&V
    • Mineralocorticoid excess – Conn’s, Cushings, liquorice excess
    • Medications
      • Diuretics, SSRIs, Steroids
      • B2 agonists, insulin
      • laxatives, enemas

 

Clinical Management

  • Mild/Moderate
    • if high risk, discuss with medical team
    • exclude low magnesium as a cause
    • consider random urine for K/creatinine ratio – > 2.5 suggests cause is renal potassium loss – if so, consider endocrinology referral
  • Mild
    • treat underlying cause
    • oral replacement – repeat potassium in 5 days
  • Moderate
    • treat underlying cause
    • ECG
    • Consider A+E if rapid change, ECG changes or cardiac symptoms
    • oral replacement + weekly potassium monitoring
  • Severe
    • refer to A+E even if asymptomatic, IV potassium may be required