Note on Concentration: Gamunex-C is supplied as a 10% solution (100 mg/mL). This calculation assumes no dilution.
Calculating Gamunex-C Infusion Parameters
Gamunex-C (Immune Globulin Injection [Human], 10% Caprylate/Chromatography Purified) requires precise calculation of infusion rates based on patient body weight to ensure safety and tolerability. This calculator helps healthcare professionals convert the prescribed weight-based dosage rate (mg/kg/min) into the volumetric flow rate (mL/hr) used by infusion pumps.
How the Calculation Works
Gamunex-C is a 10% solution, meaning it contains:
0.1 grams per mL
100 mg per mL
The formula to convert the clinical order (mg/kg/min) to the pump setting (mL/hr) is:
Ensure that patients with pre-existing renal insufficiency or those at risk of renal dysfunction are infused at the minimum practicable rate. For these patients, discontinuation of infusion should be considered if renal function deteriorates.
function calculateGamunex() {
// 1. Get Input Values
var weightInput = document.getElementById('patientWeight').value;
var weightUnit = document.getElementById('weightUnit').value;
var totalDoseGrams = document.getElementById('totalDose').value;
var infusionRateMgKgMin = document.getElementById('infusionRate').value;
// 2. Validate Inputs
if (!weightInput || !totalDoseGrams || !infusionRateMgKgMin) {
alert("Please fill in all fields (Weight, Total Dose, and Target Rate).");
return;
}
var weight = parseFloat(weightInput);
var dose = parseFloat(totalDoseGrams);
var rate = parseFloat(infusionRateMgKgMin);
if (isNaN(weight) || isNaN(dose) || isNaN(rate) || weight <= 0 || dose <= 0 || rate <= 0) {
alert("Please enter valid positive numbers.");
return;
}
// 3. Convert Weight to Kg if necessary
var weightKg = weight;
if (weightUnit === 'lbs') {
weightKg = weight / 2.20462;
}
// 4. Constants for Gamunex-C (10% solution)
var concentrationMgPerMl = 100; // 100 mg/mL
var concentrationGramsPerMl = 0.1; // 0.1 g/mL
// 5. Calculate Total Volume (mL)
// Volume = Total Grams / Grams per mL
var totalVolumeMl = dose / concentrationGramsPerMl;
// 6. Calculate Pump Rate (mL/hr)
// Formula: (mg/kg/min * kg * 60 min/hr) / mg/mL
var pumpRateMlHr = (rate * weightKg * 60) / concentrationMgPerMl;
// 7. Calculate Duration (Hours and Minutes)
// Time = Volume / Rate
var totalHoursDecimal = totalVolumeMl / pumpRateMlHr;
var hours = Math.floor(totalHoursDecimal);
var minutes = Math.round((totalHoursDecimal – hours) * 60);
// 8. Update UI
document.getElementById('displayVolume').innerHTML = totalVolumeMl.toFixed(1) + " mL";
document.getElementById('displayRate').innerHTML = pumpRateMlHr.toFixed(1) + " mL/hr";
// Handle minute overflow or clean display
if (minutes === 60) {
hours = hours + 1;
minutes = 0;
}
// Display Infinity protection
if (!isFinite(pumpRateMlHr)) {
document.getElementById('displayRate').innerHTML = "Check Inputs";
document.getElementById('displayTime').innerHTML = "–";
} else {
document.getElementById('displayTime').innerHTML = hours + " hr " + minutes + " min";
}
// Show results container
document.getElementById('results').style.display = 'block';
}