What are the recommended dilution concentrations and preparation methods for adrenaline (epinephrine) for intravenous infusion in cardiac arrest, subcutaneous or intramuscular anaphylaxis, and local infiltration anesthesia?

Adrenaline Dilution Recommendations

For anaphylaxis, use intramuscular epinephrine 0.2-0.5 mg of 1:1000 (1 mg/mL) undiluted solution; for IV use in anaphylactic shock, dilute to 1:10,000 (0.1 mg/mL) and give 0.05-0.1 mg boluses; for cardiac arrest, use standard 1 mg IV doses every 3-5 minutes; and for local anesthesia, dilute to 1:200,000 to 1:3,200,000 concentrations.

Anaphylaxis (Non-Cardiac Arrest)

Intramuscular/Subcutaneous Administration (First-Line)

• Concentration: 1:1000 (1 mg/mL) - no dilution required 1, 2
• Dose: 0.2-0.5 mg (0.2-0.5 mL) for adults; 0.01 mg/kg for children under 30 kg 1, 2
• Route: Intramuscular into anterolateral thigh (preferred) or subcutaneous 1, 2
• Frequency: Repeat every 5-15 minutes as needed 1
• Rationale: IM administration is preferred because it provides rapid peak plasma concentrations, is safe, and is easy to administer 1

Intravenous Administration (Alternative When IV Access Present)

• Concentration: 1:10,000 (0.1 mg/mL) - requires dilution 1
• Dose: 0.05-0.1 mg (5-10% of cardiac arrest dose) 1
• Critical Safety Point: This is a 10-fold lower dose than cardiac arrest dosing. Confusion between these concentrations has caused fatal iatrogenic overdoses with severe cardiac dysfunction 3

Continuous IV Infusion (For Refractory Shock)

• Preparation: Add 1 mg epinephrine (1 mL of 1:1000) to 1000 mL normal saline 4
• Starting rate: 2 mcg/min (2 mL/min or 120 mL/h) 4
• Titration: Increase up to 10 mcg/min (10 mL/min or 600 mL/h) based on blood pressure, heart rate, and oxygenation 4
• Alternative dosing: 5-15 mcg/min for maintenance 1

Cardiac Arrest (Including Anaphylaxis-Induced)

Standard Dosing

• Concentration: Can use either 1:1000 or 1:10,000 2
• Dose: 1 mg IV/IO every 3-5 minutes 1, 5
• Preparation: If using 1:1000 (1 mg/mL), give 1 mL; if using 1:10,000 (0.1 mg/mL), give 10 mL
• Evidence: High-dose epinephrine (0.2 mg/kg) showed no survival benefit over standard 1 mg dosing in large randomized trials 6

Post-Arrest Shock (Anaphylaxis)

• Use continuous infusion at 5-15 mcg/min as described above 1

Local Infiltration Anesthesia

Concentration Range

• Effective range: 1:50,000 to 1:3,200,000 7
• Recommended optimal: 1:200,000 to 1:3,200,000 7
• Rationale: Even dilute concentrations (1:3,200,000) increase analgesia duration by ~100%, while 1:200,000 increases duration by ~200% 7

Preparation Examples

• 1:200,000: 0.005 mg/mL (5 mcg/mL) - add 0.1 mL of 1:1000 to 20 mL local anesthetic
• Maximum adrenaline content: Limited to 0.25 mg total when using vasoconstrictor-containing solutions 8

Clinical Application

• Epinephrine prolongs both lidocaine and bupivacaine duration in dose-dependent fashion 7
• Vasoconstriction effect correlates with prolonged analgesia, particularly in first 15 minutes 7
• For intraocular surgery: dilute 1 mL to 100-1000 mL ophthalmic irrigation fluid (1:100 to 1:1000) 2

Critical Safety Considerations

Common Pitfalls to Avoid

1. Dosing confusion: The most dangerous error is giving cardiac arrest dose (1 mg IV push) to anaphylaxis patients who need 0.05-0.1 mg 3. This 10-20 fold overdose causes severe cardiac dysfunction and has been fatal.

2. Packaging solutions: Stock prefilled, clearly labeled IM syringes (0.3-0.5 mg) separate from IV cardiac arrest syringes to prevent confusion 3

3. Route selection: Never delay IM epinephrine while attempting IV access in anaphylaxis - IM is first-line 1

4. Dilution requirement: All IV epinephrine for anaphylaxis and continuous infusions must be diluted 2. The 1 mg/mL concentration is too concentrated for direct IV bolus outside cardiac arrest.

Storage and Preparation

• Protect from light until use 2
• Store at room temperature 20-25°C 2
• Inspect for discoloration or particulates before use 2
• Do not use if colored, cloudy, or contains particles 2