Potassium Infusion Rate Calculator

Potassium Infusion Rate Calculator

Calculate IV Pump Rate (mL/hr) based on mEq/hr requirements

*Standard peripheral rate is usually 10 mEq/hr. Central access may allow higher rates.

Infusion Results

Understanding Potassium Infusion Rates

Potassium chloride (KCl) is a critical electrolyte replacement used in clinical settings to treat hypokalemia (low serum potassium). Because potassium is highly caustic to veins and can cause lethal cardiac arrhythmias if administered too quickly, precise calculation of the infusion rate is vital for patient safety.

The Calculation Formula

To determine the IV pump rate in milliliters per hour (mL/hr) when you have a specific milliequivalent per hour (mEq/hr) order, we use the following formula:

Pump Rate (mL/hr) = [Desired Dose (mEq/hr) × Bag Volume (mL)] / Total Potassium in Bag (mEq)

Standard Safety Guidelines

  • Peripheral IV Access: Generally limited to a maximum rate of 10 mEq/hr to prevent phlebitis and pain.
  • Central IV Access: Rates of 20 mEq/hr or higher may be used in severe cases, typically requiring cardiac monitoring.
  • Concentration: Standard concentrations often range from 20 mEq/1000mL to 40 mEq/100mL for concentrated boluses via central lines.

Practical Example

Suppose a physician orders 10 mEq/hr of Potassium Chloride. The pharmacy provides a bag containing 40 mEq of KCl in 1000 mL of Normal Saline.

  1. Total Potassium: 40 mEq
  2. Total Volume: 1000 mL
  3. Desired Dose: 10 mEq/hr
  4. Calculation: (10 × 1000) / 40 = 250 mL/hr

In this scenario, you would set the IV pump to 250 mL/hr to deliver exactly 10 mEq of potassium every hour.

Medical Disclaimer: This calculator is for educational purposes only. Always verify calculations with a second provider and follow your facility's specific protocols for high-alert medications.

function calculateKRate() { var kAmt = parseFloat(document.getElementById('potassium_amt').value); var volAmt = parseFloat(document.getElementById('bag_vol').value); var desiredDose = parseFloat(document.getElementById('desired_dose').value); var resultBox = document.getElementById('potassium_result_box'); var output = document.getElementById('calc_output'); if (isNaN(kAmt) || isNaN(volAmt) || isNaN(desiredDose) || kAmt <= 0 || volAmt <= 0 || desiredDose <= 0) { alert("Please enter valid positive numbers for all fields."); return; } // Formula: (Desired mEq/hr * Total mL) / Total mEq = mL/hr var mlPerHour = (desired_dose.value * bag_vol.value) / potassium_amt.value; var concentration = potassium_amt.value / bag_vol.value; var duration = potassium_amt.value / desired_dose.value; var html = 'Pump Flow Rate: ' + mlPerHour.toFixed(2) + ' mL/hr'; html += 'Concentration: ' + concentration.toFixed(3) + ' mEq/mL'; html += 'Total Infusion Time: ' + duration.toFixed(2) + ' hours'; if (desiredDose > 10) { html += '⚠️ Warning: Infusion rates > 10 mEq/hr typically require central venous access and cardiac monitoring.'; } output.innerHTML = html; resultBox.style.display = 'block'; }

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