Hyperkalemia

 

 

 

Considerations

 

  • Emergency situation with potential for life threatening arrhythmias, cardiac arrest

  • Etiology:

    • Shift:

      • ​Metabolic or respiratory acidosis, diabetic ketoacidosis

      • Digoxin toxicity

    • Total body excess:

      • ​Rhabdomyolysis (malignant hyperthermia, crush injuries, burns)

      • ​Post cardiopulmonary bypass 

      • ​Iatrogenic (IV or oral)

      • ​Hemolysis

      • ​Tumor lysis

      • ​Transfusion (massive transfusion, old packed red blood cells)

      • ​Renal failure

      • ​Hypoaldosteronism 

      • Addison's

    • Drugs (succinylcholine, ACE inhibitors, beta blockers, spironolactone, NSAIDs, cyclosporin)

  • Systemic effects

    • Arrhythmias

    • Muscle weakness

  • Drug interactions

    • Succinylcholine contraindicated

    • Non-depolarizer muscle relaxants: resistance

 

 

Management

 

  • Stabilize myocardium:

    • Calcium gluconate 100 mg/kg

  • Shift potassium intracellularly:

    • Insulin 0.1 units/kg + Glucose 0.5-1 g/kg (25 g for every 10 U insulin)

    • Sodium bicarbonate 1 mEq/kg

    • Ventolin 5-10 mg via nebulizer or 5 mcg/kg IV

    • Hyperventilation

    • Epinephrine

  • Eliminate potassium:

    • Furosemide 20-40mg IV

    • Kayexalate 30 g PR or PO

    • Dialysis

 


ECG changes

 

  • Mild (5.5-6.5 mEq/L): peaked T waves, prolonged PR interval (1st degree AV block)

  • Moderate (6.5-8 mEq/L): loss of P wave, prolonged QRS, ST segment elevation, ectopic beats/escape rhythms

  • Severe (>8.0 mEq/L): progressive widening of QRS, bundle branch blocks, fascicular blocks, sine wave, ventricular fibrillation, asystole