Treatment for Inpatient Hypocalcemia (Calcium 6.4)
For an inpatient with hypocalcemia (calcium level of 6.4 mg/dL), immediate treatment with intravenous calcium gluconate is recommended. 1, 2
Immediate Management
- Administer calcium gluconate 1-2 g (100-200 mL of 10% solution) IV slowly with ECG monitoring 1, 2
- Dilute calcium gluconate in 5% dextrose or normal saline to a concentration of 10-50 mg/mL prior to administration 2
- Administer at a rate not exceeding 200 mg/minute in adults to avoid cardiac complications 2
- Monitor vital signs and ECG during administration to detect potential cardiac arrhythmias 2
Dosing Considerations
- For symptomatic hypocalcemia, calcium gluconate 50-100 mg/kg IV is the recommended dose 1
- Calcium chloride may be preferable to calcium gluconate in settings of abnormal liver function, as it contains more elemental calcium (10 mL of 10% calcium chloride contains 270 mg of elemental calcium compared to 90 mg in 10 mL of 10% calcium gluconate) 3
- For patients with renal impairment, initiate calcium gluconate at the lowest dose of the recommended range and monitor serum calcium levels every 4 hours 2
Monitoring
- Measure serum calcium every 4 to 6 hours during intermittent infusions and every 1 to 4 hours during continuous infusion 2
- Monitor for signs of hypercalcemia, which can occur with rapid administration 1
- Check for drug incompatibilities - do not mix calcium gluconate with ceftriaxone as it can lead to precipitation 2
Follow-up Management
- After acute management, transition to oral calcium supplementation (calcium carbonate) for long-term management 1
- Consider adding vitamin D supplementation if 25-hydroxyvitamin D is <30 ng/mL 1
- For chronic hypocalcemia, total elemental calcium intake (dietary plus supplements) should not exceed 2,000 mg/day 1
Important Considerations
- Hypocalcemia in the inpatient setting is often associated with increased mortality and need for massive transfusion, particularly in trauma patients 3, 4
- Low calcium concentrations can impair cardiac contractility and systemic vascular resistance 3
- Calcium levels below 0.8 mmol/L ionized (or total calcium approximately 7.5 mg/dL) are associated with cardiac dysrhythmias and require prompt correction 3
- The safety of calcium gluconate for long-term use has not been established, so transition to oral therapy when appropriate 2