What is the protocol for intravenous (IV) calcium correction in patients with hypocalcemia?

IV Calcium Correction Protocol for Hypocalcemia

For IV calcium correction in hypocalcemia, calcium chloride is the preferred agent (10% solution, 10mL contains 270mg elemental calcium), administered slowly with ECG monitoring, especially for severe or symptomatic cases requiring rapid correction. 1

Assessment and Monitoring

• Monitor ionized calcium levels (normal range: 1.1-1.3 mmol/L)
• Assess for symptoms of hypocalcemia:
  • Neuromuscular irritability, tetany, paresthesias
  • Muscle cramps and spasms
  • Chvostek's sign, Trousseau's sign
  • Seizures, abnormal involuntary movements
  • Cardiac manifestations: QT prolongation, arrhythmias, hypotension

IV Calcium Preparations

Calcium Chloride (Preferred for Critical Situations)

• 10% calcium chloride: 10mL contains 270mg of elemental calcium 1
• Preferred in emergency situations, liver dysfunction, and critical care
• Provides more rapid increase in ionized calcium than gluconate
• Must be administered through central line or secure peripheral IV (risk of tissue necrosis)

Calcium Gluconate

• 10% calcium gluconate: 10mL contains only 90mg of elemental calcium 1
• Can be used for peripheral administration (less irritating to veins)
• Requires liver function to release ionized calcium

Administration Protocol

Severe Symptomatic Hypocalcemia

1. Calcium chloride 10%: 10-20mL (1-2g) IV push over 5-10 minutes with ECG monitoring 1
2. May repeat every 10-20 minutes based on clinical response and calcium levels
3. For continuous infusion: 0.2-0.4 mL/kg/hr (0.02-0.04 g/kg/hr) 1

Moderate Hypocalcemia (ionized Ca <1.0 mmol/L)

1. Calcium gluconate: 4g IV infusion at 1g/hour 2
   • This regimen achieves normal calcium levels in 95% of patients
   • Achieves ionized calcium >1.12 mmol/L in 70% of patients

Mild Hypocalcemia (ionized Ca 1.0-1.12 mmol/L)

1. Calcium gluconate: 1-2g IV infusion at 1g/hour 3
   • Effective in normalizing calcium in 79% of patients with mild hypocalcemia

During Massive Transfusion

• Monitor ionized calcium every 4-6 hours 4
• Administer calcium chloride if ionized calcium levels are low or ECG changes suggest hypocalcemia 4

Important Precautions

• Administer slowly with ECG monitoring (risk of bradycardia, arrhythmias)
• Do not mix calcium with:
  • Fluids containing phosphate or bicarbonate (precipitation risk) 4
  • Ceftriaxone (fatal precipitates, especially in neonates) 4
• Use with caution with cardiac glycosides (risk of arrhythmias) 4
• Avoid if phosphate levels are elevated (risk of calcium phosphate precipitation) 4
• Central line preferred for calcium chloride; secure peripheral IV for calcium gluconate

Follow-up Monitoring

• Monitor ionized calcium every 4-6 hours initially until stable
• Then every 1-2 days until normalized
• Adjust dosing based on calcium levels and clinical response
• Transition to oral calcium supplementation when appropriate

Special Considerations

• In renal impairment: Start at lower doses and monitor more frequently 4
• In liver dysfunction: Prefer calcium chloride over gluconate 1
• In trauma patients: Hypocalcemia increases mortality risk and need for massive transfusion 4
• During massive transfusion: Citrate in blood products chelates calcium, requiring more frequent monitoring and replacement 4

By following this protocol, you can effectively correct hypocalcemia while minimizing risks of complications such as arrhythmias, tissue necrosis, or overcorrection.