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Be careful not to eat too many bananas.

High-Yield Tips

  • Always check Therapeutic Guidelines or your local guidelines prior to actually dosing a patient (as this information may be out of date by the time you read it)
  • If serum [K] > 6.5, it is quite concerning
  • Management
    • ECG
    • IV calcium gluconate
    • IV dextrose 50% + insulin (alternatively, salbutamol)
    • Resonium
    • IV sodium bicarbonate (if metabolic acidosis present)
    • 0.9% sodium chloride for rehydration


Serum potassium concentration > 5.2 mmol/L.

Normal range: 3.5-5.2 mmol/L


  • Mild: 5.2 < serum [potassium] ≤ 6.0
  • Moderate: 6.0 < serum [potassium] ≤ 7.0
  • Severe: serum [potassium] > 7.0


Is it pseudohyperkalaemia or true hyperkalaemia?

  • Pseudohyperkalaemia: falsely elevated serum [potassium]. Causes include:
    • Mechanical trauma during venepuncture → cell lysis → K release
    • Clotting (in a patient with thrombocytosis) → K moves out of platelets
    • Sample obtained from vein proximal to site of K infusion
  • True hyperkalaemia causes:
    • ↑ K release from cells
      1. Metabolic acidosis (other than lactic acidosis or ketoacidosis)
        • Rare to see hyperkalaemia caused by respiratory acidosis too
      2. Insulin deficiency (+/- combined with hyperglycaemia and hyperosmolality)
        • Mechanism: (normally insulin promotes K entry into cells) in an insulin-deficient state with hyperglycaemia and hyperosmolality
          • → water moves by osmosis from within cells to ECF → raises intracelullar [K] → favourable gradient for passive movement of K to ECF
          • → body in 'fasting state' + insulin not able to inhibit β-oxidation → ketosis → ketoacidosis → H/K co-transporter shifts protons intracellularly in exchange for K to minimise extracellular acid-base disturbances → hyperkalaemia
      3. Other causes of ↓ insulin levels
        • Somatostatin (or analogues e.g. octreotide)
        • Fasting
      4. ↑ tissue catabolism
        • Trauma
        • Rhabdomyolysis
        • Tumour lysis syndrome
        • Severe hypothermia
      5. Other
        • Overdose of digitalis or related digitalis glycosides
        • Red cell transfusion
        • Succinylcholine
        • K absorption from GIT bleed
        • Hyperkalaemic periodic paralysis
    • ↓ urinary K excretion
      1. ↓ ALD secretion
      2. ↓ response to aldosterone (e.g. use of K-sparing diuretics aka aldosterone antagonists)
      3. ↓ distal sodium and water delivery 2° to hypovolaemia
      4. Acute and chronic kidney disease

Clinical Manifestations

  • Muscle weakness or paralysis
  • Cardiac conduction abnormalities and arrhythmias

ECG Changes

Changes usually progress as serum [K] increases.

  • 5.5-6.5 mmol/L: Tall peaked T waves
  • 6.5-7.5 mmol/L: Loss of P waves, prolonged PR interval
  • 7.0-8.0 mmol/L: Widening of QRS complex
  • 8.0-10.0 mmol/L: Sine wave, ventricular arrhythmia, asystole
LITFL: Hyperkalaemia


Emergency Management

  1. Primary survey
  2. ECG (or telemetry preferred for continuous monitoring)
  3. IV calcium gluconate 10% 10mL IV over 2-3 mins into a large vein
    • Note: effect of this infusion is short-lived and dose may need to be repeated in 30-60 mins whilst simultaneously undertaking measures to reduce potassium
    • Purpose: stabilise cardiac membrane to prevent cardiac arrest
    • Indication: cardiac arrhythmia or severe ECG changes of acute hyperkalaemia
  4. IV sodium bicarbonate 8.4% 50mL IV over 5-10 mins
    • Purpose: correction of volume depletion (if present) + any underlying metabolic acidosis
    • May be repeated in 60-120 mins
    • Fluid replacement may need to be continued with sodium chloride 0.9%
  5. Glucose 50% 50mL IV over 5 mins + short-acting insulin (e.g. aspart 100 units/mL) 10 units IV bolus
    • Note: MUST give dextrose before insulin as dextrose can compromise cannula and if insulin is given first and subsequent glucose not given → hypoglycaemia
    • Glucose 50% may cause vascular irritation
    • Alternatively to above regimen of Glucose 50%, can give glucose 10% 250mL over 15 mins
    • Consider ongoing monitoring of BSL and need for further glucose + insulin
    • Effective in renal failure
  6. Nebulised salbutamol e.g. 5mg neb q1-2h (max 10-20mg in 24h)
  7. Cessation of any exacerbating medications e.g. potassium-sparing diuretics
  8. Sodium polystyrene sulfonate 15g (suspended in 45-60mL of water) PO TDS or QID
    • Purpose: to reduce GIT potassium absorption
    • This treatment lowers the serum potassium concentration by 0.5 to 1 mmol/L over 1 to 6 hours.
    • Note: as sodium polystyrene can ↑ Na, consider calcium polystyrene sulfonate (same dose) instead
  9. Situational treatment options:
    • Dialysis
    • Corticosteroid replacement (e.g. IV hydrocortisone) if aetiology is adrenal insufficiency and hypoaldosteronism + don't use insulin


  1. LITFL: Hyperkalaemia
  2. UpToDate: Causes and evaluation of hyperkalemia in adults
  3. UpToDate: Clinical manifestations of hyperkalaemia in adults
  4. Therapeutic Guidelines: Hyperkalaemia

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