Potassium Infusion Rate Calculator
Calculate infusion rates (mL/hr) and dosage rates (mEq/hr) for Potassium Chloride (KCl) administration.
IV Pump Flow Rate:
— mL/hr
Potassium Delivery Rate:
— mEq/hr
Solution Concentration:
— mEq/mL
How to Calculate Potassium Infusion Rates
Calculating the correct infusion rate for Potassium Chloride (KCl) is a critical nursing and pharmacy competency. Rapid administration of potassium can lead to dangerous cardiac arrhythmias and cardiac arrest. This calculator helps clinicians determine the IV pump settings and verifies the safety of the mEq/hr delivery rate.
The Formulas
There are three main components to calculating potassium infusion parameters:
1. IV Pump Flow Rate (mL/hr):
This determines how fast the fluid runs through the IV pump.
Formula: Total Volume (mL) ÷ Infusion Time (hr) = Rate (mL/hr)
2. Potassium Delivery Rate (mEq/hr):
This is the most critical safety metric. It measures how much medication enters the bloodstream per hour.
Formula: Total Dose (mEq) ÷ Infusion Time (hr) = Potassium Rate (mEq/hr)
3. Concentration (mEq/mL):
High concentrations can cause phlebitis (vein irritation) in peripheral lines.
Formula: Total Dose (mEq) ÷ Total Volume (mL) = Concentration (mEq/mL)
Standard Safety Guidelines
While institutional protocols vary, general clinical guidelines for Potassium Chloride infusion are:
- Peripheral Line Limit: Generally 10 mEq/hr. The concentration should typically not exceed 10 mEq per 100mL (0.1 mEq/mL) to avoid burning sensation and phlebitis.
- Central Line Limit: Generally 20 mEq/hr. Because central lines empty into larger vessels with higher blood flow, higher concentrations and rates are tolerated, though cardiac monitoring is often required for rates > 10 mEq/hr.
- ICU Settings: Rates higher than 20 mEq/hr are extremely rare and strictly reserved for critical care settings with continuous ECG monitoring during severe hypokalemia protocols.
Calculation Example
A physician orders 20 mEq of KCl in 100 mL of Normal Saline to run over 2 hours.
- Flow Rate: 100 mL ÷ 2 hr = 50 mL/hr
- Potassium Rate: 20 mEq ÷ 2 hr = 10 mEq/hr (Safe for most peripheral lines)
- Concentration: 20 mEq ÷ 100 mL = 0.2 mEq/mL
Please enter valid positive numbers for all fields.
';
resultDiv.style.display = "block";
document.getElementById("flowRateResult").innerHTML = "–";
document.getElementById("doseRateResult").innerHTML = "–";
document.getElementById("concentrationResult").innerHTML = "–";
return;
}
// 4. Calculations
var flowRate = volVal / timeVal;
var doseRate = doseVal / timeVal;
var concentration = doseVal / volVal;
// 5. Update UI
document.getElementById("flowRateResult").innerHTML = flowRate.toFixed(1) + " mL/hr";
document.getElementById("doseRateResult").innerHTML = doseRate.toFixed(2) + " mEq/hr";
document.getElementById("concentrationResult").innerHTML = concentration.toFixed(3) + " mEq/mL";
// 6. Safety Logic and Warnings
var safetyHTML = "";
// Check Rate vs Route
if (doseRate <= 10) {
safetyHTML += 'Safe Range (Peripheral): The rate is ≤ 10 mEq/hr, which is generally considered safe for peripheral IV administration.
';
} else if (doseRate > 10 && doseRate <= 20) {
safetyHTML += 'Caution (Central Recommended): The rate is between 10-20 mEq/hr. This typically requires a Central Line and cardiac monitoring depending on hospital protocol. High risk of phlebitis in peripheral veins.
';
} else {
safetyHTML += 'DANGER – HIGH RATE: The rate exceeds 20 mEq/hr. This is highly dangerous and typically contraindicated outside of specialized ICU protocols with continuous cardiac monitoring. Verify order immediately.
';
}
// Check Concentration (Peripheral usually max 10mEq/100mL = 0.1 mEq/mL)
if (concentration > 0.1 && doseRate <= 10) {
safetyHTML += 'Concentration Warning: Although the hourly rate is low, the concentration (> 0.1 mEq/mL) is high for a peripheral line and may cause pain or phlebitis.
';
}
safetyDiv.innerHTML = safetyHTML;
resultDiv.style.display = "block";
}