Heparin Infusion Rate Calculation

by

Heparin Infusion Rate Calculator

Leave blank for non-weight based
Units/kg/hr Units/hr

Calculation Results:

Infusion Rate: 0 mL/hr

Concentration: 0 Units/mL

Total Dose: 0 Units/hr

Please enter valid positive numbers for all required fields.

Understanding Heparin Infusion Rate Calculations

Heparin is a potent anticoagulant used to prevent and treat blood clots (thrombosis). In clinical settings, heparin is often administered via a continuous intravenous (IV) infusion. Because heparin dosing is highly sensitive and carries a risk of bleeding, calculating the precise infusion rate in milliliters per hour (mL/hr) is a critical skill for nurses and healthcare providers.

The Heparin Calculation Formula

To determine the pump setting (mL/hr), you first need to determine the concentration of the medication in the IV bag and the hourly dose required by the patient.

  1. Concentration (Units/mL) = Total Units in Bag / Total Volume of Bag (mL)
  2. Total Hourly Dose (Units/hr):
    • If weight-based: Dose (Units/kg/hr) × Patient Weight (kg)
    • If non-weight based: The ordered Dose (Units/hr)
  3. Infusion Rate (mL/hr) = Total Hourly Dose (Units/hr) / Concentration (Units/mL)

Real-World Example

Scenario: A doctor orders a Heparin drip at 18 Units/kg/hr for a patient weighing 80 kg. The pharmacy provides a bag containing 25,000 Units of Heparin in 250 mL of Normal Saline.

  • Concentration: 25,000 Units / 250 mL = 100 Units/mL
  • Hourly Dose: 18 Units × 80 kg = 1,440 Units/hr
  • Infusion Rate: 1,440 Units/hr / 100 Units/mL = 14.4 mL/hr

Important Safety Notes

Heparin concentrations can vary by facility protocol. Common concentrations include 100 Units/mL (25,000 units in 250mL) or 50 Units/mL (25,000 units in 500mL). Always double-check the bag label and verify weight-based calculations with a second healthcare professional to ensure patient safety.

function calculateHeparinRate() { var totalUnits = parseFloat(document.getElementById('totalUnits').value); var totalVolume = parseFloat(document.getElementById('totalVolume').value); var patientWeight = parseFloat(document.getElementById('patientWeight').value); var doseRate = parseFloat(document.getElementById('doseRate').value); var doseType = document.getElementById('doseType').value; var resultDiv = document.getElementById('heparinResult'); var errorDiv = document.getElementById('heparinError'); // Reset displays resultDiv.style.display = 'none'; errorDiv.style.display = 'none'; // Validation if (isNaN(totalUnits) || totalUnits <= 0 || isNaN(totalVolume) || totalVolume <= 0 || isNaN(doseRate) || doseRate <= 0) { errorDiv.style.display = 'block'; return; } if (doseType === 'kgHr' && (isNaN(patientWeight) || patientWeight <= 0)) { errorDiv.textContent = "Please enter a valid patient weight for weight-based dosing."; errorDiv.style.display = 'block'; return; } // Calculation var concentration = totalUnits / totalVolume; var hourlyDose; if (doseType === 'kgHr') { hourlyDose = doseRate * patientWeight; } else { hourlyDose = doseRate; } var infusionRate = hourlyDose / concentration; // Output formatting document.getElementById('rateOutput').innerText = infusionRate.toFixed(2); document.getElementById('concentrationOutput').innerText = concentration.toLocaleString(); document.getElementById('totalHourlyDose').innerText = hourlyDose.toLocaleString(); resultDiv.style.display = 'block'; }

Leave a Comment