Adrenaline Infusion Rate Calculator
Enter actual body weight
Typical start: 0.01 – 0.1
Mass of Adrenaline in syringe/bag
Total volume of the solution
Solution Concentration:
0 mcg/mL
Total Drug (mcg):
0 mcg
Required Pump Flow Rate:
0 mL/hr
How to Calculate Adrenaline Infusion Rate
Adrenaline (Epinephrine) is a potent vasoactive medication commonly used in critical care settings to treat hypotension, shock, and cardiac arrest. Accurate calculation of the infusion rate is vital for patient safety, as small errors in dosing can lead to significant hemodynamic instability.
⚠️ MEDICAL DISCLAIMER: This calculator is for educational and verification purposes only. It should not replace clinical judgment or hospital protocols. Always double-check calculations and pump settings independently.
The Adrenaline Infusion Formula
Most hospitals use a weight-based dosing strategy for continuous adrenaline infusions, measured in micrograms per kilogram per minute (mcg/kg/min). To set an infusion pump, you typically need to convert this desired dose into a flow rate of milliliters per hour (mL/hr).
The standard mathematical formula used is:
Rate (mL/hr) = [Dose (mcg/kg/min) × Weight (kg) × 60 (min/hr)] / Concentration (mcg/mL)
Step-by-Step Calculation Logic
- Determine Total Micrograms: Convert the total milligrams (mg) of drug in the bag to micrograms (mcg).
Formula: mg × 1000 = mcg - Calculate Concentration: Divide the total micrograms by the total volume of the solution.
Formula: Total mcg / Total Volume (mL) = Concentration (mcg/mL) - Calculate Hourly Dose: Determine how many micrograms the patient needs per hour.
Formula: Dose (mcg/kg/min) × Weight (kg) × 60 minutes - Determine Flow Rate: Divide the hourly dose by the concentration.
Formula: Hourly Dose / Concentration = Rate (mL/hr)
Example Calculation
Let's look at a realistic clinical scenario to understand how the numbers work:
- Patient Weight: 80 kg
- Desired Dose: 0.05 mcg/kg/min
- Preparation: 4 mg of Adrenaline diluted in 50 mL of saline (Standard Strength)
Step 1: Concentration
4 mg = 4,000 mcg.
4,000 mcg / 50 mL = 80 mcg/mL.
Step 2: Hourly Requirement
0.05 mcg/kg/min × 80 kg × 60 min = 240 mcg/hr.
Step 3: Pump Setting
240 mcg/hr / 80 mcg/mL = 3.0 mL/hr.
Standard Concentrations
To reduce calculation errors, many institutions use standardized concentrations for Adrenaline infusions:
- Standard Strength: 4mg in 50mL (80 mcg/mL)
- Double Strength: 8mg in 50mL (160 mcg/mL)
- Quad Strength: 16mg in 50mL (320 mcg/mL)
- Peripherally Diluted: 1mg in 100mL (10 mcg/mL) – Note: Central line access is preferred for vasoactive drugs.
Why Weight-Based Dosing?
Adrenaline is dosed based on body weight to ensure the therapeutic effect is proportional to the patient's size. While a fixed rate (mcg/min) is sometimes used in specific cardiac life support scenarios, weight-based dosing (mcg/kg/min) allows for finer titration in continuous critical care support.