What is the maximum KCl infusion rate per kilogram per hour?

• A. 0.2 mEq/kg/hr
• B. 0.5 mEq/kg/hr
• C. 1.0 mEq/kg/hr
• D. 2.0 mEq/kg/hr

Answer: (B)

Potassium IV replacement must be done at a rate that safely supports the heart while correcting the deficit. The maximum safe infusion rate is 0.5 mEq/kg per hour. This ceiling helps prevent a rapid rise in serum potassium that could trigger dangerous cardiac arrhythmias, especially in patients with evolving deficits or impaired renal function. Rates at 1.0 or 2.0 mEq/kg/hr exceed that safety threshold and raise the risk of hyperkalemia and arrhythmias, while a much slower rate like 0.2 mEq/kg/hr would be inefficient for correcting deficits promptly. So, 0.5 mEq/kg/hr is the appropriate maximum.