From the FDA Drug Label
The dose and rate of administration are dependent upon the specific condition of each patient. Recommended administration rates should not usually exceed 10 mEq/hour or 200 mEq for a 24-hour period if the serum potassium level is greater than 2.5 mEq/liter In urgent cases where the serum potassium level is less than 2 mEq/liter or where severe hypokalemia is a threat (serum potassium level less than 2 mEq/liter and electrocardiographic changes and/or muscle paralysis), rates up to 40 mEq/hour or 400 mEq over a 24-hour period can be administered very carefully when guided by continuous monitoring of the EKG and frequent serum K+ determinations to avoid hyperkalemia and cardiac arrest.
The recommended IV potassium rate for a 12-year-old patient with hypokalemia is:
- Not to exceed 10 mEq/hour if the serum potassium level is greater than 2.5 mEq/liter
- Up to 40 mEq/hour in urgent cases where the serum potassium level is less than 2 mEq/liter, with close monitoring of EKG and serum potassium levels 1 Key considerations:
- Administration via central route is recommended for thorough dilution and avoidance of extravasation
- Continuous monitoring of EKG and frequent serum potassium determinations are necessary to avoid hyperkalemia and cardiac arrest.
From the Research
For a 12-year-old patient with hypokalemia, the recommended intravenous potassium replacement is typically 0.5-1 mEq/kg/dose (maximum 40 mEq per dose), administered at a rate not exceeding 0.5 mEq/kg/hour or 1 mEq/kg/hour in severe cases, as supported by the most recent study 2. The concentration should not exceed 40 mEq/L through a peripheral IV line or 80 mEq/L through a central line.
- Potassium chloride (KCl) is the most commonly used formulation.
- The infusion requires cardiac monitoring, especially at higher rates.
- The total daily dose should generally not exceed 3 mEq/kg/day.
- Treatment should be guided by serial potassium measurements, with a goal of achieving serum potassium levels of 3.5-4.5 mEq/L.
- Potassium should always be diluted in compatible fluids like normal saline or dextrose solutions and never given as a direct IV push.
- Magnesium levels should be checked and corrected if low, as hypomagnesemia can cause refractory hypokalemia, as noted in 3 and 4.
- The underlying cause of hypokalemia should be identified and treated simultaneously for optimal management, as emphasized in 2 and 5. It is essential to consider the potential relationship between serum potassium concentrations and electrocardiographic characteristics, as explored in 6, to ensure comprehensive care for the patient.