Understanding Heparin Infusion Calculations
Heparin is a medication used to prevent blood clots. Calculating the correct infusion rate is vital for patient safety and therapeutic efficacy. The standard approach involves determining the patient's weight, the concentration of the heparin solution, and the physician's prescribed dosage per unit of weight per hour.
How it Works:
The calculation proceeds in a few logical steps:
- Calculate Total Daily Dose: First, we determine the total units of heparin needed per hour for the patient. This is done by multiplying the patient's weight in kilograms by the desired dose per kilogram per hour.
Formula: Total Units/hr = Patient Weight (kg) × Desired Dose (units/kg/hr)
- Calculate Infusion Volume: Next, we need to figure out how many milliliters (mL) of the heparin solution contain this required number of units. This involves using the concentration of the heparin vial (units per milliliter).
Formula: Volume (mL/hr) = Total Units/hr / Heparin Concentration (units/mL)
The result provides the volume of the heparin solution that needs to be infused per hour. This volume is then programmed into an infusion pump.
Important Considerations:
- Always double-check your calculations.
- Refer to the specific product information for the heparin preparation being used.
- Patient weight, renal function, and other clinical factors can influence heparin dosing.
- This calculator is a supplementary tool and does not replace clinical judgment or standard hospital protocols.
.heparin-calculator-wrapper {
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gap: 20px;
margin: 20px auto;
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function calculateHeparinRate() {
var weight = parseFloat(document.getElementById("weight").value);
var concentration = parseFloat(document.getElementById("concentration").value);
var desiredDose = parseFloat(document.getElementById("desiredDose").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = "; // Clear previous result
if (isNaN(weight) || isNaN(concentration) || isNaN(desiredDose)) {
resultDiv.innerHTML = '
Please enter valid numbers for all fields.';
return;
}
if (weight <= 0 || concentration <= 0 || desiredDose <= 0) {
resultDiv.innerHTML = '
All values must be positive.';
return;
}
// Calculate total units per hour
var totalUnitsPerHour = weight * desiredDose;
// Calculate infusion rate in mL per hour
var infusionRateMlPerHour = totalUnitsPerHour / concentration;
// Display the result
resultDiv.innerHTML = "
Infusion Rate: " + infusionRateMlPerHour.toFixed(2) + " mL/hr";
}