Disclaimer: This tool is for educational purposes only. Always double-check calculations and follow hospital protocols and physician orders exactly before administering medication.
function calculateLidoFlow() {
var dose = parseFloat(document.getElementById('lidoDose').value);
var selectVal = document.getElementById('lidoConcSelect').value;
var concentration;
if (selectVal === 'custom') {
concentration = parseFloat(document.getElementById('customConcVal').value);
} else {
concentration = parseFloat(selectVal);
}
var resultDiv = document.getElementById('lidoResultArea');
var outputDiv = document.getElementById('lidoOutput');
var summaryDiv = document.getElementById('lidoSummary');
if (isNaN(dose) || isNaN(concentration) || dose <= 0 || concentration <= 0) {
alert("Please enter valid positive numbers for dose and concentration.");
return;
}
// Formula: (mg/min * 60 min/hr) / (mg/mL) = mL/hr
var flowRate = (dose * 60) / concentration;
var totalMgPerHour = dose * 60;
outputDiv.innerText = flowRate.toFixed(2) + " mL/hr";
summaryDiv.innerHTML = "At a concentration of " + concentration + " mg/mL, to deliver a dose of " + dose + " mg/min, the pump should be set to " + flowRate.toFixed(2) + " mL/hr (Total: " + totalMgPerHour + " mg/hr).";
resultDiv.style.display = 'block';
}
How to Calculate Lidocaine Flow Rates
In clinical settings, Lidocaine is frequently used as a Class Ib antiarrhythmic to treat ventricular arrhythmias or as part of a local anesthetic regimen. When administered via continuous intravenous infusion, it is standard practice to order the dose in milligrams per minute (mg/min). However, infusion pumps require the setting in milliliters per hour (mL/hr).
The Flow Rate Formula
To convert the physician's order into a pump setting, you must first identify the concentration of the Lidocaine bag. Most standard premixed bags have a concentration of 4 mg/mL (for example, 2 grams of Lidocaine in 500 mL of D5W).
Standard Dosing: Typical maintenance infusion rates for Lidocaine range from 1 to 4 mg/min.
Toxicity: Monitor for signs of Lidocaine toxicity, including "slurred speech," altered mental status, muscle twitching, or seizures (often referred to as SAMS: Slurred speech, Altered central nervous system, Muscle twitching, Seizures).
Double Checks: High-alert medications like Lidocaine should always be double-checked by a second licensed professional before starting the infusion.