Dobutamine Infusion Rate Calculator
Required Rate: 0 mL/hr
Understanding Dobutamine Infusion Calculations
Dobutamine is a sympathomimetic medication used in the treatment of heart failure and cardiogenic shock. Its primary mechanism is stimulating beta-1 receptors to increase cardiac output. Because it is a potent vasoactive medication, calculating the precise infusion rate in milliliters per hour (mL/hr) based on a weight-based dose (mcg/kg/min) is critical for patient safety.
The Dobutamine Formula
To calculate the infusion rate, you must first determine the concentration of the solution and then convert the weight-based dose into a flow rate. The standard formula used by clinicians is:
Rate (mL/hr) = [Dose (mcg/kg/min) × Weight (kg) × 60 (min/hr)] ÷ Concentration (mcg/mL)
Step-by-Step Calculation Guide
- Determine Concentration: Convert the drug amount from milligrams (mg) to micrograms (mcg) by multiplying by 1,000. Then divide by the total volume of the bag (mL).
- Example: 250 mg in 250 mL = 250,000 mcg / 250 mL = 1,000 mcg/mL.
- Identify Patient Weight: Use the patient's actual weight in kilograms (kg).
- Apply the Math: Multiply the desired dose (mcg/kg/min) by the weight and then by 60 (to convert minutes to hours). Finally, divide by the concentration found in step 1.
Calculation Example
Suppose a physician orders a Dobutamine infusion at 5 mcg/kg/min for a patient weighing 80 kg. The pharmacy provides a bag containing 500 mg of Dobutamine in 250 mL of D5W.
- Concentration: (500 mg × 1000) / 250 mL = 2,000 mcg/mL.
- Calculation: (5 mcg × 80 kg × 60 min) / 2,000 mcg/mL.
- Result: 24,000 / 2,000 = 12 mL/hr.
Medical Disclaimer: This calculator is intended for educational purposes only. Always double-check calculations manually and follow institutional protocols and pharmacy labeling before administering vasoactive medications.