Calcium Gluconate Dosing in Hemodialysis Patients with Hyperkalemia
For hemodialysis patients with severe hyperkalemia and ECG changes, administer 1,000-2,000 mg (10-20 mL of 10% solution) of intravenous calcium gluconate over 2-5 minutes with continuous cardiac monitoring. 1
Standard Dosing Protocol
The FDA-approved dosing for calcium gluconate is 1,000-3,000 mg (10-30 mL of 10% solution) administered intravenously over 2-5 minutes for adults with hyperkalemia. 2 This translates to 93-279 mg of elemental calcium (4.65-13.95 mEq). 2
Administration Guidelines
- Dilute calcium gluconate to a concentration of 10-50 mg/mL in 5% dextrose or normal saline prior to bolus administration. 2
- Do NOT exceed an infusion rate of 200 mg/minute in adults. 2
- Continuous ECG monitoring is mandatory during and after administration. 1, 2
- Administer via a secure intravenous line to avoid calcinosis cutis and tissue necrosis. 2
Repeat Dosing Strategy
If no ECG improvement occurs within 5-10 minutes after the initial dose, repeat the same dose of calcium gluconate (10-20 mL of 10% solution). 1 The effects of calcium are temporary, lasting only 30-60 minutes, and do not reduce total body potassium—they only stabilize the cardiac membrane. 1, 3
Critical Considerations for Hemodialysis Patients
Renal Impairment Dosing
For patients with renal impairment (which includes all hemodialysis patients), initiate calcium gluconate at the lowest recommended dose and monitor serum calcium every 4 hours. 2 This means starting with 1,000 mg (10 mL of 10% solution) rather than the higher end of the dosing range. 2
Hemodialysis as Definitive Treatment
Hemodialysis is the most effective and reliable method for potassium removal in severe hyperkalemia, especially in patients with end-stage renal disease. 1 Calcium gluconate is a temporizing measure only—it does NOT remove potassium from the body. 1, 3 Arrange for urgent hemodialysis immediately after membrane stabilization with calcium. 1
Special Populations and Caveats
Pediatric Hemodialysis Patients
For pediatric patients on hemodialysis, the dose is 100-200 mg/kg (1-2 mL/kg of 10% solution) administered slowly with ECG monitoring, not exceeding 100 mg/minute. 4 This is consistent with the FDA guidance for pediatric dosing. 2
Tumor Lysis Syndrome Context
In patients with tumor lysis syndrome and hyperkalemia, calcium gluconate dosing remains 100-200 mg/kg for pediatric patients and the standard adult dose for adults, but care must be taken because increased calcium might increase the risk of calcium phosphate precipitation. 4 If phosphate levels are high, renal consultation is necessary. 4
Malignant Hyperthermia Exception
In patients with malignant hyperthermia and hyperkalemia, intravenous calcium 0.1 mmol/kg should only be used in extremis, as calcium influx may contribute to myoplasmic calcium overload. 4 This is a rare exception where calcium use should be minimized. 4
Common Pitfalls to Avoid
- Never delay calcium administration while waiting for repeat lab confirmation if ECG changes are present. 1 ECG changes indicate urgent treatment regardless of the exact potassium level. 1
- Do not mix calcium gluconate with fluids containing bicarbonate or phosphate—precipitation will result. 2
- Do not mix calcium gluconate with ceftriaxone, as this can lead to fatal ceftriaxone-calcium precipitates. 2
- Remember that absent or atypical ECG changes do not exclude the necessity for immediate intervention in severe hyperkalemia. 5
- Calcium stabilizes the membrane but does NOT lower potassium—you must still administer insulin/glucose, beta-agonists, and arrange for dialysis. 1, 3
Monitoring Protocol
Measure serum calcium every 4-6 hours during intermittent calcium infusions and every 1-4 hours during continuous infusion. 2 For hemodialysis patients, this is particularly important given their impaired calcium homeostasis. 2
Concurrent Therapies
After membrane stabilization with calcium, immediately administer insulin 10 units IV with 25g dextrose and nebulized albuterol 10-20 mg to shift potassium intracellularly while arranging urgent hemodialysis. 1 These agents work within 15-30 minutes but only last 4-6 hours. 1 Sodium bicarbonate should ONLY be added if metabolic acidosis is present (pH <7.35, bicarbonate <22 mEq/L). 1