What is the recommended dose of calcium gluconate (Ca gluconate) in milligrams for treating hyperkalemia?

Recommended Dose of Calcium Gluconate for Hyperkalemia Treatment

The recommended dose of calcium gluconate for treating hyperkalemia is 10 mL of 10% solution (1 gram) administered intravenously, which may be repeated after 5-10 minutes if no effect is observed. 1

Mechanism of Action and Timing

Calcium gluconate works by:

• Rapidly stabilizing cardiac cell membranes within 1-3 minutes
• Reducing the membrane excitatory effects of potassium on cardiac tissue
• Minimizing the potential for cardiac arrhythmias
• Note that it only minimally reduces serum potassium concentrations 1

Administration Guidelines

Route and Rate

• Administer intravenously through a central venous access when possible
• Give as a slow infusion with ECG monitoring to avoid bradycardia 1
• Preferably administer through a central venous catheter to avoid severe skin and soft tissue injury 2

Monitoring

• Closely monitor ECG during administration
• Observe for resolution of ECG changes associated with hyperkalemia (peaked T waves, prolonged QRS complexes) 1
• Monitor serum calcium levels, especially in patients with chronic kidney disease 2

Special Considerations

Repeat Dosing

• If no effect is observed within 5-10 minutes of initial administration, another dose of calcium gluconate may be given 1
• For life-threatening hyperkalemia with ECG changes, calcium gluconate should be given immediately 3

Efficacy

• Calcium gluconate is effective primarily for treating main rhythm disorders due to hyperkalemia 4
• It may be less effective for non-rhythm ECG disorders caused by hyperkalemia 4

Comprehensive Hyperkalemia Management

Calcium gluconate should be used as part of a comprehensive approach:

1. Membrane stabilization: Calcium gluconate 10% - 10 mL IV
2. Intracellular shift of potassium:
   • Insulin (0.1 units/kg) plus glucose (25% dextrose 2 mL/kg) 1
   • Inhaled β-agonists (e.g., salbutamol)
3. Potassium elimination:
   • Loop diuretics
   • Sodium polystyrene sulfonate 1 g/kg orally or by enema for mild hyperkalemia (<6 mmol/L) 1
   • Consider hemodialysis for severe cases 1

Pediatric Dosing

For pediatric patients with symptomatic hyperkalemia:

• Calcium gluconate 100-200 mg/kg/dose via slow infusion with ECG monitoring 1
• Use caution when administering with sodium bicarbonate (do not administer through the same line) 1

Pitfalls and Caveats

• Calcium gluconate contains only 9% elemental calcium compared to calcium carbonate (40%) 2
• Verify elevated potassium levels with a second sample to rule out fictitious hyperkalemia from hemolysis during phlebotomy 1
• Use caution when administering calcium in patients with hyperphosphatemia, as it may increase the risk of calcium phosphate precipitation in tissues 1
• Calcium gluconate primarily stabilizes cardiac membranes but does not significantly reduce serum potassium levels 1

By following these guidelines, you can effectively use calcium gluconate as part of the emergency management of hyperkalemia to reduce morbidity and mortality associated with this potentially life-threatening condition.