Treatment of Hyperkalemia-Induced Ventricular Fibrillation
The immediate treatment for hyperkalemia-induced ventricular fibrillation requires calcium administration for cardiac membrane stabilization, followed by insulin with glucose for intracellular potassium shifting, and measures to eliminate excess potassium from the body. 1
Emergency Management Algorithm
1. Immediate Cardiac Stabilization
- Calcium administration: Give calcium gluconate 10% at 20 mg/kg (0.2 mL/kg) IV over 5-10 minutes 1
2. Intracellular Potassium Shifting
- Insulin with glucose: Administer 10 units regular insulin IV with 50 mL of 25% dextrose 1
- Alternative dosing: 0.1 unit/kg IV of regular insulin with 400 mg/kg glucose (ratio of 1 unit insulin for every 4g glucose)
- Onset: 15-30 minutes; Duration: 1-2 hours
- Sodium bicarbonate: 50 mEq IV over 5 minutes if metabolic acidosis is present 1
- Alternative dosing: 1-2 mEq/kg IV given slowly
- Onset: 15-30 minutes; Duration: 1-2 hours
- Beta-agonists: Consider nebulized albuterol 10-20 mg over 15 minutes 1
- Onset: 15-30 minutes; Duration: 2-4 hours
3. Potassium Elimination
- Loop diuretics: IV furosemide if renal function permits 1
- Potassium binders: Consider emergency administration of a potassium binder 1
- Options include patiromer (Veltassa) 8.4g, sodium zirconium cyclosilicate (Lokelma) 5-10g, or sodium polystyrene sulfonate 15-30g
4. Continuous Monitoring
- Continuous cardiac monitoring is essential 1
- Serial ECGs to monitor for improvement 1
- Frequent serum potassium measurements to assess response to therapy 1
ECG Risk Stratification
Hyperkalemia severity can be assessed by ECG changes, which correlate with increasing potassium levels 1, 3:
- 5.5-6.5 mmol/L: Peaked/tented T waves (early sign)
- 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, VF, asystole, or PEA
ECG findings that increase risk for adverse events include 3:
- QRS prolongation (RR 4.74)
- Bradycardia (HR<50) (RR 12.29)
- Junctional rhythm (RR 7.46)
Important Clinical Considerations
- Hyperkalemia is associated with increased risk for all-cause mortality and malignant arrhythmias such as ventricular fibrillation 4
- All patients with severe hyperkalemia who experienced adverse events in one study had at least one hyperkalemic ECG abnormality 3
- Adverse events typically occur prior to treatment with calcium and potassium-lowering interventions 3
- Hyperkalemia can increase the organization of ventricular fibrillation and may even terminate it by depolarizing the reversal potential of the inward rectifier potassium current, which reduces excitability 5
- Interstitial hyperkalemia may play a role in the genesis of wide complex electromechanical dissociation seen after prolonged cardiac arrest 6
Pitfalls and Caveats
- Do not rely solely on peaked T waves to risk-stratify patients, as they don't significantly correlate with short-term adverse events 3
- Avoid using lidocaine or phenytoin for digitalis-induced hyperkalemia and arrhythmias (Class III recommendation) 7
- When administering insulin and glucose, monitor for hypoglycemia, especially in patients with renal dysfunction
- Calcium should be administered with caution in patients on digoxin due to risk of digoxin toxicity
- Sodium bicarbonate should be used cautiously in volume-overloaded patients
- Potassium levels should ideally be maintained ≤5 mmol/L, especially in patients with heart failure, chronic kidney disease, or diabetes mellitus 7