What is the approach to managing hyperkalemia?

Management of Hyperkalemia

The approach to hyperkalemia should follow a stepwise algorithm based on severity, with immediate administration of IV calcium gluconate for cardiac stabilization in severe cases (>6.5 mmol/L), followed by insulin with glucose and beta-agonists to shift potassium intracellularly, while simultaneously initiating measures to eliminate potassium from the body. 1

Assessment and Classification

Hyperkalemia is classified as:

• Mild: 5.0-5.5 mmol/L
• Moderate: 5.6-6.5 mmol/L
• Severe: >6.5 mmol/L 1

Initial Evaluation

1. Obtain ECG immediately to assess for cardiac effects:

   • K+ 5.5-6.5 mmol/L: Peaked/tented T waves (early sign)
   • K+ 6.5-7.5 mmol/L: Prolonged PR interval, flattened P waves
   • K+ 7.0-8.0 mmol/L: Widened QRS, deep S waves
   • K+ >10 mmol/L: Sinusoidal pattern, VF, asystole, or PEA 1

2. Identify potential causes:

   • Medications (RAASi, MRAs, potassium-sparing diuretics)
   • Renal dysfunction
   • Metabolic acidosis
   • Tissue breakdown
   • Excessive potassium intake 1, 2

Treatment Algorithm

1. Severe Hyperkalemia (>6.5 mmol/L) or ECG Changes

Treat as a medical emergency with these steps in sequence:

1. Cardiac Membrane Stabilization:

   • Calcium gluconate 10% solution, 15-30 mL IV over 2-5 minutes
   • Onset: 1-3 minutes; Duration: 30-60 minutes 1
   • Monitor ECG during administration

2. Intracellular Potassium Shift:

   • Regular insulin 10 units IV with 50 mL of 25% dextrose
   • Inhaled beta-agonists (albuterol 10-20 mg nebulized over 15 minutes)
   • Consider sodium bicarbonate 50 mEq IV (especially with metabolic acidosis) 1, 3

3. Potassium Elimination:

   • Loop diuretics (if renal function adequate)
   • Initiate hemodialysis for:
     • Severe refractory hyperkalemia
     • Severe renal failure
     • Life-threatening ECG changes despite treatment 1, 3

2. Moderate Hyperkalemia (5.6-6.5 mmol/L) without ECG Changes

1. Intracellular shifting agents (insulin/glucose, beta-agonists)
2. Potassium elimination:
   • Loop diuretics if renal function adequate
   • Potassium binders:
     • Sodium Zirconium Cyclosilicate (SZC) - faster onset, acts in small and large intestines
     • Patiromer - slower onset but effective for ongoing management 1, 4

3. Mild Hyperkalemia (5.0-5.5 mmol/L)

1. Review and adjust medications that increase potassium
2. Consider potassium binders for chronic management
3. Increase monitoring frequency 1

Monitoring and Follow-up

• Continuous cardiac monitoring during treatment
• Serial potassium measurements:
  • First check: 1-2 hours after initial treatment
  • Subsequent checks: every 4-6 hours until stable 1
• Monitor for rebound hyperkalemia, especially with shifting agents alone

Special Considerations

• High-Risk Populations: Patients with heart failure, CKD, or diabetes require more aggressive management even for potassium levels >5.0 mmol/L due to increased mortality risk 1

• Chronic Hyperkalemia Management:

  • Newer potassium binders (patiromer or SZC) are preferred over Sodium Polystyrene Sulfonate (SPS) due to better selectivity and tolerability 1, 2
  • Avoid discontinuing beneficial medications (RAASi) if possible; instead, use potassium binders to maintain these therapies 2
  • Consider sodium-glucose cotransporter 2 inhibitors in appropriate patients 2

• Dietary Considerations:

  • Focus on reducing non-plant sources of potassium rather than broad dietary restrictions 2
  • Sodium restriction (<2g/day) may help prevent recurrence 1

Common Pitfalls to Avoid

• Failing to obtain an ECG immediately in suspected hyperkalemia
• Administering potassium-containing fluids (Lactated Ringer's or Hartmann's solution)
• Relying solely on shifting agents without addressing total body potassium elimination
• Overlooking the need for continuous cardiac monitoring during treatment
• Neglecting to check for rebound hyperkalemia after initial treatment 1, 3