Calcium Replacement Therapy for Hypocalcemia

Introduction to Calcium Replacement

The American College of Medical Toxicology recommends administering calcium gluconate 4 grams IV infused at 1 gram/hour over 4 hours for moderate to severe hypocalcemia (ionized calcium <1.0 mmol/L), or 1-2 grams for mild hypocalcemia (ionized calcium 1.0-1.12 mmol/L) 1

Calcium chloride is strongly preferred in trauma, massive transfusion, and critically ill patients with liver dysfunction because it delivers 3 times more elemental calcium (270 mg per 10 mL vs 90 mg per 10 mL) and produces more rapid increases in ionized calcium without requiring hepatic metabolism 2
Calcium gluconate is preferred for peripheral IV administration due to significantly less tissue irritation and lower risk of severe skin necrosis from extravasation 1

For mild hypocalcemia (ionized Ca 1.0-1.12 mmol/L), adults should receive 1-2 grams calcium gluconate IV infused at 1 gram/hour 1
For moderate to severe hypocalcemia (ionized Ca <1.0 mmol/L), pediatrics should receive 50-100 mg/kg calcium gluconate IV infused slowly over 30-60 minutes 4, 1

Never mix calcium with sodium bicarbonate - causes immediate precipitation 4, 1, 3
Never mix calcium with phosphate-containing fluids - causes precipitation 4, 1, 3
Correct magnesium deficiency first - hypocalcemia cannot be fully corrected without adequate magnesium 3

In massive transfusion/trauma, calcium chloride is preferred due to impaired hepatic citrate metabolism 2, 3
For asymptomatic hypocalcemia in tumor lysis syndrome, no intervention is recommended 4
For symptomatic patients in tumor lysis syndrome, calcium gluconate 50-100 mg/kg IV administered slowly with ECG monitoring is recommended 4

For acute symptomatic hypocalcemia in pediatrics, 20 mg/kg (0.2 mL/kg of 10% solution) calcium chloride IV/IO can be administered 3
For mild to moderate hypocalcemia in pediatrics, 60 mg/kg calcium gluconate infused over 30-60 minutes can be administered 1