Calcium Gluconate Dosing for Mild Hypocalcemia
For mild hypocalcemia, administer 60 mg/kg of calcium gluconate intravenously, infused over 30-60 minutes. 1
Dosing Guidelines Based on Severity
- For mild hypocalcemia (ionized calcium 1.0-1.12 mmol/L), administer 2 grams of calcium gluconate intravenously 2
- For moderate to severe hypocalcemia (ionized calcium <1.0 mmol/L), administer 4 grams of calcium gluconate intravenously 3
- Calcium gluconate should be infused at a rate of 1 gram per hour to minimize adverse effects 2, 3
Administration Considerations
- Calcium gluconate (10%) contains 9.3 mg (0.47 mEq) of elemental calcium per 100 mg 4
- Administer through a secure intravenous line to prevent extravasation 4
- For pediatric patients with hypocalcemia, calcium gluconate dose is 60 mg/kg 1
- For adult patients, calcium gluconate can be administered as a 10-15 mL of 10% solution (1-1.5 grams) 5
- Monitor serum ionized calcium levels during intermittent infusions every 4-6 hours and during continuous infusion every 1-4 hours 4
Clinical Monitoring
- After calcium gluconate administration, serum ionized calcium concentrations typically plateau within 10 hours after completion of the infusion 2
- About half of the administered elemental calcium dose is retained in the exchangeable calcium space 2
- Monitor ECG during administration, especially in patients receiving cardiac glycosides 1
- Stop injection if symptomatic bradycardia occurs 1
Special Considerations
- Administration through a central venous catheter is preferred; extravasation through a peripheral IV line may cause severe skin and soft tissue injury 1
- Calcium gluconate is preferred over calcium chloride for peripheral administration due to less tissue irritation 1
- Calcium gluconate is not physically compatible with fluids containing phosphate or bicarbonate; precipitation may result if mixed 4
- For patients with renal impairment, initiate with the lower limit of the dosage range and monitor serum calcium levels more frequently 4
Treatment Efficacy
- A 2-gram dose of calcium gluconate increases ionized calcium from 1.07 to 1.17 mmol/L in mild hypocalcemia 2
- A 4-gram dose increases ionized calcium from 0.92 to 1.16 mmol/L in moderate to severe hypocalcemia 2, 3
- The 4-gram regimen achieves serum ionized calcium >1.0 mmol/L in 95% of patients with moderate to severe hypocalcemia 3
- Hypocalcemia typically normalizes within the first four days after ICU admission in most patients 6
Potential Adverse Effects
- Rapid administration may cause hypotension, bradycardia, and cardiac arrhythmias 4
- Tissue necrosis and calcinosis can occur with extravasation 4
- Mild hypercalcemia may develop in approximately 10% of patients receiving 4 grams of calcium gluconate 3
- Synergistic arrhythmias may occur if calcium and cardiac glycosides are administered together 4
Remember that calcium replacement should be guided by clinical symptoms and laboratory values, with more frequent monitoring in critically ill patients to avoid both persistent hypocalcemia and iatrogenic hypercalcemia.