20- Hyperkalemia

• Hyperkalemia


  Serum K concentration of >5.5 mmol/L
• Causes of hyperkalemia


  • Reduced excretion
  • Increased release from tissues
• Reduced excretion causes


  • Renal failure (acute or chronic)
  • Low aldosterone (ACE I, Spironolactone, K+ sparing diuresis, RTA IV, Addison's disease)
• Increased release from tissues causes


  • Tissue destruction (Hemolysis, Rhabdomyolysis, Tumor lysis syndrome, Burns)
  • Acidosis
  • Low insulin-hyperglycemia
  • BB, digoxin, heparin
• Must rule out pseudohyperkalemia (prolonged inserted cannula, leukocytosis, thrombocytosis)
• Presentation of hyperkalemia


  • Weakness
  • Paralysis
  • Ileus
  • Cardiac conduction disorders
• ECG findings in hyperkalemia

  • Peaked T-wave
  • Wide QRS
• ECG is the most urgent test in cases of hyperkalemia
• Hyperkalemic emergency criteria


  • Muscle weakness/paralysis
  • Cardiac ECG changes
  • K+ > 6.5
  • K+ > 5.5 + significant renal impairment + ongoing tissue breakdown
• Treatment for hyperkalemia (K<5.5 or no severe renal impairment)

  1. Reversal of cause (ex: stop causative medications)

  2. Dietary modification

  3. +/- diuretics (loop)

  4. Kayexalate (sodium polystyrene sulfonate)

  5. Calcium resonium
• Treatment for hyperkalemic emergency

  1. 10 ml of 10% calcium gluconate or calcium chloride IV over 2 min (protects the heart; does NOT lower K+, must be given to any patient with ECG changes)

  2. IV insulin + glucose (D50) (drives K+ intracellularly)

  3. Nebulized salbutamol

  4. Bicarbonate (drives potassium into cells but should be used most when acidosis causes hyperkalemia)
• If K > 7 à dialysis
• Patiromer


  A long-term, oral potassium-lowering agent used in chronic hyperkalemia. It allows the use of ACEI/ARB despite rising K levels.
• Medications causing hyperkalemia


  • BB
  • ACE I
  • Spironolactone
  • Statins
  • Digoxin intoxication
  • Amiodarone
  • NSAIDs
  • Lithium
• Medications causing hypokalemia


  • Diuretics (loop thiazide and acetazolamide)
  • Laxatives and enemas
  • Steroids
  • B2 agonists
  • Amphotericin B, penicillin, aminoglycosides
  • Cisplatin, cyclosporine
  • Topiramate