How to Mix a 1:100,000 Adrenaline Solution
To prepare a 1:100,000 adrenaline solution, dilute 1 mL of 1:1000 (1 mg/mL) adrenaline with 9 mL of normal saline (0.9% NaCl) to create a total volume of 10 mL containing 0.1 mg/mL (1:10,000), then further dilute 1 mL of this 1:10,000 solution with 9 mL of normal saline to achieve the final 1:100,000 concentration (0.01 mg/mL).
Understanding Adrenaline Concentrations
The evidence provided primarily discusses 1:1000 (1 mg/mL) and 1:10,000 (0.1 mg/mL) concentrations used in emergency medicine 1, 2. The 1:100,000 concentration is commonly used in surgical and dental procedures for local vasoconstriction when mixed with local anesthetics like lidocaine 3, 4, 5.
Step-by-Step Dilution Method
Starting Material
- Begin with adrenaline 1:1000 solution (1 mg/mL), which is the standard commercially available concentration 6
Two-Step Dilution Process
Step 1: Create 1:10,000 solution
- Draw up 1 mL of 1:1000 adrenaline (contains 1 mg)
- Add 9 mL of normal saline
- Total volume = 10 mL containing 1 mg = 0.1 mg/mL (1:10,000)
Step 2: Create 1:100,000 solution
- Draw up 1 mL of the 1:10,000 solution (contains 0.1 mg)
- Add 9 mL of normal saline
- Total volume = 10 mL containing 0.1 mg = 0.01 mg/mL (1:100,000)
Alternative Single-Step Method
For larger volumes, you can use a single-step dilution:
- Add 1 mL of 1:1000 adrenaline to 99 mL of normal saline
- Total volume = 100 mL containing 1 mg = 0.01 mg/mL (1:100,000)
Clinical Context and Safety
Common Uses
The 1:100,000 concentration is typically used:
- Mixed with local anesthetics (e.g., 1% or 2% lidocaine) for surgical procedures 3, 4, 5
- For vasoconstriction during neck surgery, dental procedures, and endoscopic sinus surgery 3, 7
- Research shows 1:100,000 and 1:200,000 concentrations provide equivalent vasoconstriction in many surgical contexts 3, 4
Critical Safety Considerations
Avoid Dosing Errors:
- The guidelines emphasize that "great care should be taken to avoid dose errors when preparing drug dilutions" 1
- Always double-check calculations and label syringes clearly with concentration and date/time of preparation
- Use only clear, colorless solutions; discard if pink or brown (indicates oxidation) 6
Storage:
- Store between 20-25°C (68-77°F)
- Protect from light and air exposure - adrenaline degrades rapidly when exposed 6
- Discard multi-dose vials 30 days after initial use 6
Concentration Verification
- 1:1000 = 1 mg/mL = 1 gram per 1000 mL
- 1:10,000 = 0.1 mg/mL = 1 gram per 10,000 mL
- 1:100,000 = 0.01 mg/mL = 1 gram per 100,000 mL
Never confuse these concentrations - using 1:1000 when 1:100,000 is intended represents a 100-fold overdose with potentially serious cardiovascular consequences 2.