Calcium Administration for Hyperkalemia

Adult Dosing

Standard dose: 15 – 30 mL of 10 % calcium gluconate administered intravenously over 2 – 5 minutes (equivalent to 1,500 – 3,000 mg of calcium gluconate). This recommendation is supported by major cardiovascular guidelines. 1, 2
Repeat dosing: If no clinical improvement (e.g., persistent ECG changes) is observed within 5 – 10 minutes, a second identical dose may be given. 3

Standard dose: 60 mg/kg of calcium gluconate given intravenously. 4
Cardiac‑arrest scenario: Administer the dose as a slow IV push. 4
Non‑arrest indications: Infuse the dose over 30 – 60 minutes. 4
Safety monitoring: Continuously monitor heart rate; discontinue the infusion if symptomatic bradycardia develops. 4

Adults: 5 – 10 mL of 10 % calcium chloride (500 – 1,000 mg) IV over 2 – 5 minutes as an alternative to calcium gluconate. 1, 2
Children: 20 mg/kg (≈0.2 mL/kg of 10 % calcium chloride) IV. 4
Rationale: Calcium chloride produces a more rapid rise in ionized calcium and is preferred for critically ill pediatric patients. 4
Substitution: Calcium gluconate may be used when calcium chloride is unavailable. 4

Calcium stabilizes myocardial cell membranes by antagonizing the depolarizing effect of elevated extracellular potassium, thereby reducing the risk of arrhythmias. The protective effect begins within 1 – 3 minutes of administration. 1, 2, 3
Important caveat: Calcium does not lower serum potassium concentrations; it solely provides cardiac membrane protection. 3

The historical evidence for calcium use in hyperkalemic cardiac arrest is limited, relying on an 1883 in‑vitro study, a 1939 canine experiment, and a 1964 case series. This constitutes low‑quality, indirect evidence. 8, 9
In a randomized controlled porcine model, calcium alone did not improve return of spontaneous circulation (OR 1.2; 95 % CI 0.4‑4.0; P = 0.76). 8, 9
A pediatric cohort of eight children with hyperkalemia‑induced cardiac arrest showed no significant difference in survival to discharge or favorable neurological outcome when calcium was administered. 8, 9
Despite these limitations, calcium remains recommended because it is the only rapid intervention that directly addresses cardiac membrane excitability in hyperkalemia. 1, 2

Line choice: Use a secure intravenous line, preferably a central venous catheter, to minimize extravasation risk. 4
Extravasation risk: Peripheral administration can cause severe skin and soft‑tissue injury, tissue necrosis, and calcinosis cutis. 4

Calcium must not be mixed with sodium bicarbonate solutions, as precipitation can occur. 4

Sodium bicarbonate: 50 mEq IV over 5 minutes to promote intracellular potassium shift. 1, 2
Insulin + glucose: 10 units regular insulin with 25 g glucose (≈50 mL D50) IV over 15‑30 minutes. 1, 2
Nebulized albuterol: 10 – 20 mg administered over 15 minutes. 1, 2
Loop diuretic: Furosemide 40 – 80 mg IV to enhance renal potassium excretion. 1, 2
Dialysis: Initiate renal replacement therapy for definitive potassium removal when indicated. 1, 2