Treatment of Hypocalcemia
The treatment of hypocalcemia should include calcium supplementation (oral or intravenous depending on severity), vitamin D supplementation, and correction of any underlying magnesium deficiency, with the specific approach determined by the severity of symptoms and serum calcium levels. 1, 2
Assessment and Classification
- Hypocalcemia can be symptomatic (presenting with neuromuscular irritability, tetany, seizures, cardiac arrhythmias) or asymptomatic 3, 4
- Ionized calcium is the physiologically active form, with normal levels ranging from 1.1 to 1.3 mmol/L 1
- Total corrected calcium levels below 8.4 mg/dL (2.10 mmol/L) indicate hypocalcemia 5
- Severe hypocalcemia is defined as total corrected calcium ≤7.5 mg/dL or ionized calcium <0.9 mmol/L 1
Acute Symptomatic Hypocalcemia Management
- For severe symptomatic hypocalcemia, intravenous calcium is the treatment of choice 2, 6
- Calcium gluconate is FDA-approved for treatment of acute symptomatic hypocalcemia in both pediatric and adult patients 2
- For IV administration:
- Dilute calcium gluconate in 5% dextrose or normal saline prior to administration 2
- For bolus administration: dilute to concentration of 10-50 mg/mL and administer at a rate not exceeding 200 mg/minute in adults 2
- For continuous infusion: dilute to 5.8-10 mg/mL 2
- Monitor patients, vital signs, and ECG during administration 1, 2
- Calcium chloride may be preferred over calcium gluconate in patients with liver dysfunction due to faster release of ionized calcium 1
- 10 mL of 10% calcium chloride contains 270 mg of elemental calcium versus only 90 mg in 10 mL of 10% calcium gluconate 1
Chronic Hypocalcemia Management
- Daily calcium and vitamin D supplementation are recommended for chronic hypocalcemia 5, 6
- Oral calcium supplementation options:
- Vitamin D supplementation:
- Magnesium supplementation is indicated for those with coexisting hypomagnesemia 5
Monitoring and Follow-up
- Measure serum calcium every 4-6 hours during intermittent infusions and every 1-4 hours during continuous infusion 2
- Regular monitoring of pH-corrected ionized calcium, magnesium, parathyroid hormone, and creatinine is recommended for chronic management 5
- Targeted monitoring of calcium concentrations should be considered during vulnerable times (perioperatively, perinatally, during severe illness) 5
- For patients with renal impairment, initiate calcium at the lowest dose of the recommended range and monitor serum calcium levels every 4 hours 2
Special Considerations
- Avoid overcorrection, which can result in iatrogenic hypercalcemia, renal calculi, and renal failure 5
- In CKD patients, total elemental calcium intake (including both dietary calcium and calcium-based phosphate binders) should not exceed 2,000 mg/day 5
- Hypocalcemia in trauma patients is often related to citrate toxicity from blood product transfusions, impaired citrate metabolism, or colloid infusions 1
- Hypocalcemia is associated with increased mortality and correlates with severity of illness in critically ill patients 8
Underlying Cause-Specific Considerations
- For hypoparathyroidism, calcium and vitamin D supplementation must be carefully titrated to avoid symptoms while keeping serum calcium in the low-normal range to minimize hypercalciuria 3, 6
- For vitamin D deficiency, correct the deficiency with appropriate vitamin D supplementation 5
- For patients with 22q11.2 deletion syndrome (DiGeorge syndrome), hypocalcemia is typically attributable to hypoparathyroidism and may require lifelong calcium and vitamin D supplementation 5
By following this structured approach to hypocalcemia management based on symptom severity, calcium levels, and underlying causes, clinicians can effectively treat this common electrolyte disorder while minimizing complications.