What is the administration protocol for Calcium gluconate (calcium gluconate) injection in treating hypocalcemia?

Administration Protocol for Calcium Gluconate Injection in Hypocalcemia

For hypocalcemia treatment, calcium gluconate should be administered intravenously at a dose of 1-2 g for mild hypocalcemia and 4 g for moderate to severe hypocalcemia, infused at a rate of 1 g/hour through a secure intravenous line, preferably a central venous catheter. 1, 2, 3

Dosing Guidelines

Adult Dosing

• Mild hypocalcemia (ionized calcium 1.0-1.12 mmol/L):
  • 1-2 g IV calcium gluconate (effective in 79% of cases) 2
• Moderate to severe hypocalcemia (ionized calcium <1.0 mmol/L):
  • 4 g IV calcium gluconate (effective in 95% of cases) 3

Pediatric Dosing

• Calcium gluconate dose: 60 mg/kg IV 4
• Calcium chloride dose (if available): 20 mg/kg (0.2 mL/kg of 10% solution) 4

Administration Method

1. Preparation:

   • Dilute calcium gluconate in normal saline or 5% dextrose
   • For continuous infusion: 2 g in 50 mL of 0.9% NaCl 5

2. Administration rate:

   • Bolus: Give by slow IV push for cardiac arrest situations 4
   • Standard infusion: 1 g/hour 2, 3
   • For critically ill patients: 1.6 g/hour may be more effective in maintaining calcium levels 5

3. Route:

   • Administer through a secure IV line
   • Central venous access is preferred, especially for continuous infusions 4, 1
   • If using peripheral IV, ensure the line is patent and monitor closely for extravasation

Monitoring

1. Calcium levels:

   • For intermittent infusions: Check serum calcium every 4-6 hours 1
   • For continuous infusions: Check serum calcium every 1-4 hours 1
   • Measure ionized calcium when available (more accurate than total calcium) 6

2. Cardiac monitoring:

   • ECG monitoring is recommended, especially with rapid administration 1
   • Stop infusion if symptomatic bradycardia occurs 4

Important Precautions

1. Extravasation risk:

   • Calcium gluconate extravasation can cause severe tissue injury and necrosis
   • Central venous administration is preferred to reduce this risk 4
   • If extravasation occurs, stop infusion immediately and treat affected area

2. Incompatibilities:

   • Do not mix with fluids containing phosphate or bicarbonate (precipitation may result) 1
   • Do not mix with sodium bicarbonate or vasoactive amines 4

3. Special populations:

   • Renal impairment: Start at lower dose range and monitor calcium levels more frequently 1
   • Elderly: Use caution, starting at lower doses 1

Clinical Pearls

• Calcium chloride contains three times more elemental calcium than calcium gluconate (27% vs 9.3%), but calcium gluconate is preferred for peripheral administration due to less tissue irritation 4
• Calcium gluconate is generally safer for peripheral administration, while calcium chloride should be reserved for central line administration 4
• In cardiac arrest situations due to hyperkalemia, hypermagnesemia, or calcium channel blocker toxicity, calcium chloride is preferred due to faster onset of action 4
• Most critically ill patients with hypocalcemia will normalize their calcium levels within 4 days, even without supplementation 6
• Failure to normalize calcium levels in severely hypocalcemic patients may be associated with increased mortality 6

Remember that adjusted calcium is not a good surrogate for ionized calcium in ICU settings, with a sensitivity of only 78.2% and specificity of 63.3% for predicting ionized hypocalcemia 6.