What are the steps for managing hyperkalemia?

Management of Hyperkalemia

The management of hyperkalemia requires a stepwise approach based on severity, with immediate administration of calcium gluconate for ECG changes, followed by insulin with glucose or beta-agonists for acute lowering, and potassium binders or hemodialysis for definitive removal. 1

Classification and Assessment

Hyperkalemia is classified by severity:

• Mild: >5.0 to <5.5 mEq/L
• Moderate: 5.5 to 6.0 mEq/L
• Severe: >6.0 mEq/L 1

ECG Changes to Monitor

• 5.5-6.5 mmol/L: Peaked/tented T waves, nonspecific ST segment abnormalities
• 6.5-7.5 mmol/L: Prolonged PR interval, flattened or absent P waves
• 7.0-8.0 mmol/L: Widened QRS, deep S waves, fusion of S and T waves

• 10 mmol/L: Sinusoidal wave pattern, ventricular fibrillation, asystole, or pulseless electrical activity 1

Treatment Algorithm

Step 1: Membrane Stabilization (for ECG changes or severe hyperkalemia)

• Calcium gluconate: 10% solution, 15-30 mL IV
  • Onset: 1-3 minutes
  • Duration: 30-60 minutes
  • Protects against cardiac arrhythmias but does not lower potassium levels 1

Step 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
  • Monitor glucose levels to prevent hypoglycemia 1

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

  • Onset: 15-30 minutes
  • Duration: 2-4 hours
  • Can be used alone or in combination with insulin/glucose 1

• Sodium bicarbonate: 50 mEq IV over 5 minutes

  • Onset: 15-30 minutes
  • Duration: 1-2 hours
  • Most effective in patients with concurrent metabolic acidosis
  • Use with caution in fluid-overloaded patients 1

Step 3: Potassium Removal from Body

• Loop diuretics: Furosemide 40-80 mg IV (if kidney function present)

  • Onset: 30-60 minutes
  • Duration: 2-4 hours
  • Higher doses may be needed in CKD patients 1

• Potassium binders:

  • Newer agents (patiromer or sodium zirconium cyclosilicate) are preferred over sodium polystyrene sulfonate due to better safety profile 1
  • Sodium zirconium cyclosilicate: 10g TID for 48 hours 1
  • Note: Sodium polystyrene sulfonate should not be used for emergency treatment of life-threatening hyperkalemia due to its delayed onset of action 2

• Hemodialysis:

  • Consider for:
    • Severe hyperkalemia (>6.5 mEq/L) resistant to medical treatment
    • Persistent ECG changes
    • Oliguric/anuric renal failure
    • End-stage renal disease
    • Severe fluid overload unresponsive to diuretics 1
  • Intermittent hemodialysis is preferred in emergency settings due to rapid potassium clearance 1

Monitoring

• Serial potassium levels every 2-4 hours until stable
• Daily electrolytes, BUN, creatinine, and acid-base status
• Point-of-care testing (e.g., iStat) for rapid assessment 1

Important Considerations and Pitfalls

Avoid These Common Mistakes

• Don't rely solely on ECG changes: Absent or atypical ECG changes do not exclude the need for immediate intervention 1
• Don't use potassium-containing fluids (e.g., Lactated Ringer's solution) in suspected hyperkalemia 1
• Don't rely solely on diuretics in anuric patients - they will likely need hemodialysis 1
• Don't use sodium polystyrene sulfonate for emergency treatment of life-threatening hyperkalemia due to its delayed onset of action 2
• Don't forget to monitor glucose levels when using insulin therapy to prevent hypoglycemia 1

Additional Considerations

• Identify and address underlying causes (medications, kidney disease, etc.)
• Consider continuing RAASi therapy when indicated, with close monitoring of potassium levels 1
• Implement lifestyle modifications for long-term management:
  • Sodium restriction (<2g/day)
  • Regular physical activity (150 min/week)
  • Weight reduction if overweight/obese
  • Limited alcohol consumption 1

Remember that hyperkalemia with levels >6.5 mEq/L or ECG changes is a medical emergency requiring immediate treatment to prevent fatal cardiac arrhythmias and muscle paralysis 1.