What is the maximum dose of calcium gluconate in hyperkalemia?

Maximum Dose of Calcium Gluconate in Hyperkalemia

The standard dose of 10% calcium gluconate for hyperkalemia is 15-30 mL (1.5-3 grams) administered intravenously over 2-5 minutes, and this dose may be repeated once if no ECG improvement is observed within 5-10 minutes. 1

Standard Dosing Protocol

• Administer 10% calcium gluconate 15-30 mL IV over 2-5 minutes for cardiac membrane stabilization in adults with hyperkalemia and ECG changes 1
• The FDA-approved maximum infusion rate is 200 mg/minute in adults (equivalent to 2 mL/minute of 10% solution), which means the 15-30 mL dose should be given over at least 2-5 minutes 2
• For pediatric patients, the dose is 100-200 mg/kg/dose via slow infusion with ECG monitoring, and the maximum infusion rate is 100 mg/minute 1, 2

Repeat Dosing Guidelines

• Monitor ECG response for 5-10 minutes after the initial dose 1
• A second dose of calcium gluconate may be administered if no clinical or ECG improvement is observed within this 5-10 minute timeframe 1
• The onset of action is rapid, occurring within 1-3 minutes of administration, but effects are temporary, lasting only 30-60 minutes 1, 3

Critical Administration Considerations

• Calcium gluconate is strongly preferred over calcium chloride when administering through a peripheral IV line, as calcium chloride can cause severe tissue injury if extravasation occurs 1
• Administer via a secure intravenous line to avoid calcinosis cutis and tissue necrosis 2
• Monitor heart rate during calcium administration and stop injection if symptomatic bradycardia occurs 1
• Calcium should not be administered through the same line as sodium bicarbonate to avoid precipitation 1

Dilution and Preparation

• For bolus administration, dilute calcium gluconate to a concentration of 10-50 mg/mL in 5% dextrose or normal saline prior to administration 2
• For continuous infusion, dilute to a concentration of 5.8-10 mg/mL 2
• Use the diluted solution immediately after preparation and inspect visually to ensure it appears clear and colorless to slightly yellow 2

Important Caveats

• Calcium administration does not lower serum potassium but protects against cardiac arrhythmias by stabilizing cardiac membranes 1
• Concurrent therapies to shift potassium intracellularly and promote elimination must be initiated simultaneously, as calcium is only a temporizing measure 1
• In patients with high phosphate levels, increased calcium might increase the risk of calcium phosphate precipitation in tissues 1
• In patients with malignant hyperthermia and hyperkalemia, calcium should only be used in extremis as it may contribute to calcium overload of the myoplasm 3

Monitoring Requirements

• Continuous cardiac monitoring is mandatory during and after administration 1, 2
• Monitor vital signs and ECG throughout the infusion 2
• If administering via continuous infusion, measure serum calcium every 1-4 hours during infusion 2