Electrolytes & Fluids

Calcium gluconate (membrane stabilization)

Emergency cardiac membrane stabilization in life-threatening hyperkalemia in dogs and cats. Antagonizes the membrane effects of hyperkalemia within 1–3 min, buying 30–60 minutes for K-shifting and K-lowering therapy to take effect. Does not itself lower serum K; pair with definitive treatment of the underlying cause.

10% calcium gluconate · 100 mg/mL · 0.465 mEq Ca²⁺/mL

Calcium GLUCONATE, not chloride. Calcium chloride is ≈3× more potent per mL, more cardiotoxic, and severely tissue-toxic on extravasation. The IV preparation for hyperkalemia is calcium gluconate. Read the vial.
Continuous ECG required throughout infusion. Stop the infusion immediately if bradycardia worsens, PR interval lengthens further, or QRS widens. Resume at half the rate after rhythm stabilizes. Hypercalcemia from too-rapid IV calcium can itself cause arrhythmias and arrest.
Calcium does NOT lower K; it stabilizes the membrane. Onset 1–3 min, duration only 30–60 min. This is bridging therapy that buys time for K-lowering treatment (insulin/dextrose, fluid therapy) and definitive correction of the underlying cause. Do not rely on calcium alone.

Hyperkalemia emergency workflow

Calcium gluconate is one of three drug-therapy components of life-threatening hyperkalemia management, alongside insulin/dextrose and fluid therapy. See the hyperkalemia emergency hub for the full workflow including ECG-finding criteria, step ordering, deobstruction or mineralocorticoid replacement as applicable, and monitoring.

Species

Dog Cat

Patient weight

lb kg

Dose (mL/kg of 10% Ca gluconate)

Published range is 0.5–1.5 mL/kg. Default 1.0 mL/kg (mid-range). Lower end (0.5) for less severe hyperkalemia or smaller patients; upper end (1.5) for severe with overt ECG changes.

Infusion duration (min)

Range 10–20 minutes. Default 15. Faster administration substantially increases the risk of bradyarrhythmias and hypotension. Continuous ECG required throughout, stop the infusion immediately if bradycardia worsens.

Awaiting input

Enter a patient weight to see the result.

Reference

How the calculation works

Total volume is dose (mL/kg) × weight. Infusion rate divides that volume over the chosen duration:

$$\text{total volume (mL)} = \text{dose}_{\text{mL/kg}} \times \text{weight}_{\text{kg}}$$

$$\text{rate (mL/min)} = \frac{\text{total volume (mL)}}{\text{duration (min)}}$$

Worked example with current inputs

Enter a patient weight to see the worked example.

Sources

Cooper ES. Urethral Obstruction. In: Silverstein DC, Hopper K, eds. Small Animal Critical Care Medicine. 3rd ed. Elsevier; 2023. Chapter 122 (cites 0.5–1.5 mL/kg of 10% calcium gluconate IV slowly over 10–20 min).
DiBartola SP. Disorders of Potassium. In: Fluid, Electrolyte, and Acid-Base Disorders in Small Animal Practice. 4th ed. Elsevier; 2012. Chapter 5 (overview of hyperkalemia mechanisms and therapy).
Stock concentration: 10% calcium gluconate USP = 100 mg/mL of the gluconate salt = 9.3 mg/mL elemental Ca = 0.465 mEq/mL Ca²⁺.