What is the treatment for severe hyperkalemia?

Treatment of Severe Hyperkalemia

For severe hyperkalemia (>6.5 mmol/L), the treatment of choice is immediate IV calcium gluconate to stabilize cardiac membranes, followed by insulin with glucose to shift potassium intracellularly, and hemodialysis for definitive potassium removal. 1

Emergency Management Algorithm

Step 1: Cardiac Membrane Stabilization

• Administer IV calcium gluconate 10% solution (15-30 mL)
  • Onset: 1-3 minutes
  • Duration: 30-60 minutes
  • Purpose: Protects the heart from arrhythmias while other treatments take effect
  • Caution: Does not lower serum potassium levels

Step 2: Intracellular Shift of Potassium

• Immediately follow calcium with:
  • Insulin with glucose: 10 units regular insulin IV with 50 mL of 25% dextrose
    • Onset: 15-30 minutes
    • Duration: 1-2 hours
  • Consider adjunctive therapies:
    • Inhaled beta-agonists: 10-20 mg nebulized over 15 minutes
    • Sodium bicarbonate: 50 mEq IV over 5 minutes (particularly if metabolic acidosis present)

Step 3: Potassium Elimination

• Hemodialysis: Most rapid and effective method for eliminating potassium 1
• Loop diuretics: Promote renal excretion (if kidney function adequate)
• Potassium binders:
  • Newer agents (patiromer, sodium zirconium cyclosilicate) preferred over sodium polystyrene sulfonate
  • Note: Sodium polystyrene sulfonate is not recommended for emergency treatment due to delayed onset of action 2, 3

ECG Monitoring and Assessment

Monitor ECG for hyperkalemia-related changes:

• 5.5-6.5 mmol/L: Peaked/tented T waves
• 6.5-7.5 mmol/L: Prolonged PR interval, flattened P waves
• 7.0-8.0 mmol/L: Widened QRS, deep S waves

• 10 mmol/L: Sinusoidal pattern, ventricular fibrillation, asystole, or PEA

Important Considerations and Pitfalls

• Do not rely solely on ECG changes to determine treatment urgency; absent or atypical ECG changes do not exclude the need for immediate intervention 4
• Repeat treatments as needed until definitive therapy (hemodialysis) can be initiated 4
• Avoid sodium polystyrene sulfonate for emergency treatment due to its delayed onset and risk of intestinal necrosis, especially when combined with sorbitol 2, 3
• Monitor potassium levels frequently during treatment to assess response
• Investigate underlying causes of hyperkalemia once the emergency is managed

Long-term Management

After acute management:

• Identify and address underlying causes
• Review medications that may contribute to hyperkalemia
• Consider potassium binders for chronic management
• Maintain RAAS inhibitors at adjusted doses when possible rather than discontinuing completely 1
• Consider SGLT2 inhibitors for patients with heart failure or kidney disease 5

The combination of calcium to stabilize cardiac membranes, insulin with glucose to shift potassium intracellularly, and hemodialysis for definitive removal represents the most effective approach to managing severe hyperkalemia and preventing potentially fatal cardiac arrhythmias.