What is the immediate treatment for hyperkalemia?

Immediate Treatment for Hyperkalemia

For severe hyperkalemia (K+ >6.0 mmol/L) with ECG changes, immediate treatment includes IV calcium gluconate (10% solution, 15-30 mL) to stabilize cardiac membranes, followed by insulin (10 units) with glucose (50 mL of 25% dextrose) to shift potassium intracellularly. 1

Assessment and Severity Classification

Hyperkalemia severity can be classified as:

• Mild: 5.0-5.5 mmol/L
• Moderate: 5.6-6.0 mmol/L
• Severe: >6.0 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, ventricular fibrillation, asystole, or PEA

Emergency Management Algorithm

Step 1: Cardiac Membrane Stabilization

• Calcium gluconate 10% solution: 15-30 mL IV over 5-10 minutes
  • Onset: 1-3 minutes
  • Duration: 30-60 minutes
  • Mechanism: Stabilizes cardiac membranes, does not lower potassium levels
  • Monitor ECG during administration 1

Step 2: Shift Potassium Intracellularly

Use one or more of the following:

• Insulin with glucose: 10 units regular insulin IV with 50 mL of 25% dextrose

  • Onset: 15-30 minutes
  • Duration: 1-2 hours 1

• Nebulized beta-agonists: 10-20 mg nebulized over 15 minutes

  • Onset: 15-30 minutes
  • Duration: 2-4 hours
  • Can be used in combination with insulin/glucose for additive effect 1, 2

• Sodium bicarbonate: 50 mEq IV over 5 minutes

  • Onset: 15-30 minutes
  • Duration: 1-2 hours
  • Most effective in patients with metabolic acidosis 1, 2

Step 3: Remove Potassium from the Body

• IV furosemide: If renal function permits 1
• Potassium binders:
  • Patiromer (Veltassa): 8.4g once daily (onset within 7 hours)
  • Sodium zirconium cyclosilicate (SZC): Faster onset (1 hour)
  • Note: Separate patiromer from other oral medications by at least 3 hours 1, 3
• Hemodialysis: For severe, refractory cases, especially with renal failure 4

Additional Immediate Interventions

1. Discontinue potassium-raising medications:

   • ACE inhibitors/ARBs
   • Potassium-sparing diuretics
   • NSAIDs
   • Potassium supplements 1

2. Continuous cardiac monitoring for patients with moderate to severe hyperkalemia 1

3. Serial ECGs to monitor for progression of changes 1

Special Considerations and Pitfalls

• Calcium administration caution: Use with extreme caution in patients on digoxin as it may potentiate digoxin toxicity 5

• Glucose with insulin caution: Monitor blood glucose closely, especially in diabetic patients, as hypoglycemia can occur 5

• Hemodialysis consideration: Should be initiated early if conventional therapies are ineffective, particularly in patients with renal failure 4

• Common pitfall: Relying solely on ECG changes to determine treatment urgency. Absence of ECG changes does not exclude the need for immediate intervention 2

• Monitoring pitfall: Failure to recheck potassium levels after initial treatment. Regular monitoring is essential as the effect of most interventions is temporary 1

After emergency management, further evaluation of the underlying cause (reduced excretion, transcellular shift, or increased intake) should guide long-term management strategies 3.