What are the steps for managing hyperkalemia?

Management of Hyperkalemia

The management of hyperkalemia requires a stepwise approach based on severity, with immediate calcium gluconate administration for patients with ECG changes, followed by insulin with glucose and/or beta-agonists to shift potassium intracellularly, and then measures to eliminate potassium from the body. 1

Assessment and Classification

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 wave
• 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

1. Emergency Stabilization (for severe hyperkalemia or ECG changes)

• Calcium gluconate: 10% solution, 15-30 mL IV (onset: 1-3 minutes, duration: 30-60 minutes) 1
  • Stabilizes cardiac membranes but does not lower potassium levels
  • First-line treatment for patients with ECG changes

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
  • Monitor glucose levels to prevent hypoglycemia
• Inhaled beta-agonists: 10-20 mg nebulized over 15 minutes (onset: 15-30 minutes, duration: 2-4 hours) 1
  • Can be used alone or in combination with insulin/glucose
• Sodium bicarbonate: 50 mEq IV over 5 minutes (onset: 15-30 minutes, duration: 1-2 hours) 1
  • Particularly useful in patients with metabolic acidosis
  • Use with caution in fluid-overloaded patients

3. Potassium Elimination

• Loop diuretics: Furosemide 40-80 mg IV (onset: 30-60 minutes, duration: 2-4 hours) 1
  • Effective only in patients with some kidney function
  • Higher doses may be needed in CKD patients
• Potassium binders:
  • Newer agents (patiromer or sodium zirconium cyclosilicate) have better safety profiles 1
  • Sodium zirconium cyclosilicate (SZC): 10g TID for 48 hours 1
  • Sodium polystyrene sulfonate: Not for emergency treatment due to delayed onset of action 2
• Hemodialysis: Consider for: 1
  • 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

Monitoring

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

Important Caveats and Pitfalls

1. Do not rely solely on ECG changes to guide treatment decisions - absent or atypical ECG changes do not exclude the need for immediate intervention 1

2. Avoid potassium-containing fluids (e.g., Lactated Ringer's solution, Hartmann's solution) in patients with suspected hyperkalemia 1

3. Do not rely on diuretics alone in anuric patients - they will likely need hemodialysis 1

4. Be cautious with sodium bicarbonate in fluid-overloaded patients as it may worsen volume status 1

5. Sodium polystyrene sulfonate should not be used for emergency treatment of life-threatening hyperkalemia due to its delayed onset of action 2

6. Monitor for rebound hyperkalemia after treatment, especially when transcellular shifts have been induced 3

7. Consider continuing RAASi therapy when indicated with close monitoring of potassium levels, as discontinuation is associated with higher risk of mortality and cardiovascular events 1

Long-term Management

• Identify and address underlying causes
• Review medications that may contribute to hyperkalemia
• Lifestyle modifications: 1
  • Sodium restriction (<2g/day)
  • Regular physical activity (150 min/week)
  • Weight reduction if overweight/obese
  • Limited alcohol consumption
• Regular monitoring of serum potassium, kidney function, and urinalysis 1