What are the guidelines for calcium gluconate infusion in treating hypocalcemia (low calcium levels) or hyperkalemia (high potassium levels)?

Calcium Gluconate Infusion Guidelines

Concentration and Preparation

Calcium gluconate injection contains 100 mg/mL, which provides 9.3 mg (0.465 mEq) of elemental calcium per mL, and must be diluted in 5% dextrose or normal saline before administration. 1

• For bolus administration: dilute to 10-50 mg/mL concentration 1
• For continuous infusion: dilute to 5.8-10 mg/mL concentration 1
• Inspect solution before use—should be clear and colorless to slightly yellow 1
• Use diluted solution immediately after preparation 1

Administration Routes and Rates

Bolus Administration

Administer via secure IV line at maximum rates of 200 mg/minute in adults or 100 mg/minute in pediatric patients to prevent life-threatening cardiac complications. 1

• Continuous ECG monitoring is mandatory during administration 1
• Stop injection immediately if symptomatic bradycardia occurs 2, 1

Continuous Infusion

For hypocalcemia treatment, infusion rates vary by age and severity 1:

• Adults with moderate-severe hypocalcemia (iCa <1 mmol/L): 4 g infused at 1 g/hour achieves normocalcemia in 95% of patients 3
• Monitor serum calcium every 1-4 hours during continuous infusion 1
• Monitor every 4-6 hours during intermittent infusions 1

Indication-Specific Dosing

Acute Symptomatic Hypocalcemia

For pediatric patients with hypocalcemia, administer 60 mg/kg infused over 30-60 minutes. 2

• In adults with moderate-severe hypocalcemia: 4 g calcium gluconate at 1 g/hour effectively corrects iCa from 0.90 to 1.16 mmol/L 3
• Approximately 50% of administered dose is retained in exchangeable calcium space 4
• Serum iCa plateaus by 10 hours post-infusion, making this the optimal time for reassessment 4

Hyperkalemia with ECG Changes

For hyperkalemia with cardiac manifestations, administer 15-30 mL of 10% calcium gluconate IV over 2-5 minutes for immediate cardiac membrane stabilization. 5

• Effects begin within 1-3 minutes but last only 30-60 minutes 5
• Calcium does not lower potassium levels—it only protects against arrhythmias 5
• In malignant hyperthermia, use calcium 0.1 mmol/kg only in extremis, as calcium influx may worsen myoplasmic calcium overload 6
• For pediatric hyperkalemia: 100-200 mg/kg/dose via slow infusion with ECG monitoring 5

Calcium Channel Blocker Toxicity

For CCB poisoning with hemodynamic instability 2:

• Initial bolus: 30-60 mL (3-6 grams) of 10% calcium gluconate IV every 10-20 minutes
• Continuous infusion: 0.6-1.2 mL/kg/hour (0.06-0.12 g/kg/hour)

Critical Safety Considerations

Drug Incompatibilities

Never mix calcium gluconate with ceftriaxone—this combination is absolutely contraindicated in neonates ≤28 days due to fatal ceftriaxone-calcium precipitates. 1

• Do not mix with bicarbonate or phosphate-containing fluids—precipitation will occur 1
• Cannot be administered through same line as sodium bicarbonate 5
• Do not mix with minocycline—calcium complexes and inactivates it 1

Cardiac Glycoside Interactions

Avoid calcium gluconate in patients on digoxin when possible, as hypercalcemia dramatically increases digoxin toxicity and risk of fatal arrhythmias. 1

• If concomitant therapy is unavoidable, give slowly in small amounts with continuous ECG monitoring 1

Extravasation and Tissue Injury

Calcium gluconate is strongly preferred over calcium chloride for peripheral IV administration because calcium chloride causes severe tissue necrosis if extravasation occurs. 5, 2

• Administer via secure IV line to prevent calcinosis cutis and tissue necrosis 1
• Central venous catheter is preferred when available 2
• If extravasation occurs, immediately discontinue infusion at that site 1
• Calcinosis cutis can occur even without extravasation 1

Special Populations

Renal Impairment

Initiate at the lowest recommended dose and monitor serum calcium every 4 hours in patients with renal dysfunction. 1

• Hemodialysis is most effective for severe hyperkalemia in renal failure patients 5

Geriatric Patients

Start at low end of dosage range due to increased risk of adverse effects 1

Patients with High Phosphate

Increased calcium administration may precipitate calcium-phosphate in tissues when phosphate levels are elevated 5

Monitoring Parameters

• Continuous ECG during bolus administration 1
• Serum calcium every 1-4 hours during continuous infusion 1
• Serum calcium every 4-6 hours during intermittent infusions 1
• Heart rate—stop if symptomatic bradycardia develops 2, 1
• Optimal reassessment timing: ≥10 hours post-infusion for equilibration 4