What is the recommended dilution for epinephrine (adrenaline) administration?

Epinephrine Dilution and Administration Guidelines

For anaphylaxis management, epinephrine should be administered intramuscularly in the anterolateral thigh at a concentration of 1:1000 (1 mg/mL) at a dose of 0.01 mg/kg up to 0.5 mg in adults and 0.3 mg in children. 1, 2, 3

Intramuscular (IM) Administration for Anaphylaxis

Standard Dosing by Weight

• Adults and children ≥30 kg (66 lbs): 0.3-0.5 mg (0.3-0.5 mL) of 1:1000 solution 3
• Children 25-30 kg (55-66 lbs): 0.3 mg (0.3 mL) of 1:1000 solution 2
• Children 10-25 kg (22-55 lbs): 0.15 mg (0.15 mL) of 1:1000 solution 2
• Children <10 kg: 0.01 mg/kg (0.01 mL/kg) of 1:1000 solution 2, 3

Administration Technique

• Inject into the anterolateral aspect of the thigh (vastus lateralis muscle) 1, 2, 3
• May be administered through clothing if necessary 3
• Use a needle long enough (at least 1/2 inch to 5/8 inch) to ensure intramuscular delivery 3
• May repeat every 5-15 minutes as necessary based on clinical response 1, 3
• Do not administer repeated injections at the same site (risk of tissue necrosis) 3

Intravenous (IV) Administration

For Anaphylactic Shock Unresponsive to IM Epinephrine

• Bolus option: 0.05-0.1 mg (0.5-1 mL of 1:10,000 solution) 1
• Infusion preparation: Add 1 mg (1 mL of 1:1000) epinephrine to 1000 mL of normal saline 1
  • Start at 2 μg/min (2 mL/min or 120 mL/hr)
  • May increase up to 10 μg/min (10 mL/min or 600 mL/hr)
  • Titrate according to blood pressure, cardiac rate, and oxygenation 1

Alternative IV Preparation

• For continuous infusion: 1 mg of 1:1000 epinephrine in 250 mL D5W (concentration 4.0 μg/mL) 2
  • Infusion rate: 1-4 μg/min (15-60 drops/min with microdrop apparatus)
  • For severe cases: 0.1-1.0 μg/kg/min, with higher doses up to 5 μg/kg/min possible 2

For Septic Shock (Different Indication)

• Dilute 10 mL (1 mg) of epinephrine in 1,000 mL of 5% dextrose solution (1 μg/mL) 4
• Infusion rate: 0.05-2 μg/kg/min, titrated to achieve desired mean arterial pressure 4

Important Clinical Considerations

Safety and Monitoring

• No absolute contraindication to epinephrine in anaphylaxis, even in patients with cardiovascular disease 1, 2
• Monitor patients receiving epinephrine with continuous cardiac monitoring, frequent BP measurements, and pulse oximetry 2
• All patients who receive epinephrine should be observed for at least 4-6 hours, with extended observation for those requiring multiple doses 2

Common Pitfalls to Avoid

1. Delayed administration - associated with increased morbidity and mortality 2, 5
2. Incorrect route - IM is preferred over subcutaneous for faster absorption 2, 6
3. Incorrect site - thigh is preferred over arm for faster absorption 1, 2
4. Underdosing - use appropriate weight-based dosing 2
5. Overreliance on antihistamines - epinephrine is the first-line treatment 1, 2

Potential Adverse Effects

• Common: anxiety, tremor, dizziness, sweating, palpitations, pallor, nausea, headache 2
• Rare but serious: ventricular arrhythmias, hypertension, angina 2, 7
• IV administration carries higher risk of potentially lethal arrhythmias 2

Epinephrine remains the cornerstone of anaphylaxis management, and its prompt administration can be lifesaving. The benefits of appropriate epinephrine administration far outweigh the risks in anaphylaxis management 5.