Management of Hyperkalemia
The management of hyperkalemia requires a stepwise approach based on severity, with immediate treatment for life-threatening cases including calcium gluconate for cardiac membrane stabilization, insulin with glucose for intracellular potassium shift, and potassium binders for definitive removal. 1
Assessment and Classification
Hyperkalemia severity can be classified as:
- Mild: 5.1-5.5 mmol/L
- Moderate: 5.6-6.5 mmol/L
- Severe: >6.5 mmol/L
ECG changes correlate with potassium levels 1:
- 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, VF, asystole, or PEA
Acute Management Algorithm
1. Cardiac Membrane Stabilization (for severe hyperkalemia or ECG changes)
- Calcium gluconate: 10% solution, 15-30 mL IV
- Onset: 1-3 minutes
- Duration: 30-60 minutes
- Purpose: Stabilizes cardiac membrane, does not lower potassium 1
2. Intracellular Shift of Potassium
- Insulin with glucose: 10 units regular insulin IV with 50 mL of 25% dextrose
- Onset: 15-30 minutes
- Duration: 1-2 hours 1
- Inhaled beta-agonists: 10-20 mg nebulized over 15 minutes
- Sodium bicarbonate: 50 mEq IV over 5 minutes
3. Potassium Removal
- Loop diuretics (if renal function permits): IV furosemide 1
- Potassium binders:
Agent Starting Dose Onset Key Considerations Patiromer (Veltassa) 8.4g once daily 7 hours Separate from other medications by 3 hours; no sodium content Sodium zirconium cyclosilicate (Lokelma) 5-10g once daily 1 hour Contains sodium (400mg per 5g); more rapid onset Sodium polystyrene sulfonate 15-30g 1-4 times daily Variable Avoid chronic use due to GI side effects; high sodium content - Hemodialysis: Most rapid and effective method for severe hyperkalemia, especially in renal failure 1, 2
Chronic Management
1. Medication Review and Adjustment
- Temporarily discontinue or reduce ACEIs/ARBs until potassium normalizes 1
- Avoid NSAIDs as they significantly increase hyperkalemia risk 1
- Review and adjust potassium-sparing diuretics, mineralocorticoid receptor antagonists, and trimethoprim-sulfamethoxazole 1
2. Monitoring Protocol
- Initial weekly potassium monitoring, then monthly 1
- Target potassium levels ≤5 mmol/L, especially in heart failure, CKD, or diabetes 1
- Mild hyperkalemia (5.1-5.5 mmol/L) may be tolerated if clinically stable in heart failure patients 1
3. Dietary Modifications
- Limit potassium intake to <40 mg/kg/day 1
- Avoid high-potassium foods: processed foods, bananas, oranges, potatoes, tomatoes, legumes, yogurt, and chocolate 1
- Recent evidence suggests focusing more on reducing non-plant sources of potassium rather than strict restriction of all potassium-rich foods 3
4. Long-term Management
- For chronic hyperkalemia, newer potassium binders (patiromer and sodium zirconium cyclosilicate) are preferred over sodium polystyrene sulfonate due to better safety profiles 4, 5
- Consider sodium-glucose cotransporter 2 (SGLT2) inhibitors to assist in maintaining RAAS inhibitors in patients with heart failure or proteinuric kidney disease 3
- Nephrology consultation for CKD stage 4 (eGFR <30 mL/min/1.73 m²) 1
Special Considerations
- In patients with heart failure, benefits of ACEI therapy often outweigh hyperkalemia risks; consider dose reduction rather than discontinuation 1
- Hyperkalemia occurs in up to 40% of heart failure patients and up to 73% in advanced CKD 1
- ECG findings may not always correlate with serum potassium levels 2
- Avoid excessive diuresis as volume depletion can worsen renal function and paradoxically increase hyperkalemia risk 1
- Insulin is the most reliable agent for promoting transcellular shift of potassium 2
By following this structured approach to hyperkalemia management, clinicians can effectively address this potentially life-threatening electrolyte disorder while minimizing complications.