What is the proper method for preparing epinephrine (adrenaline) solutions, the final concentration, and examples of when to use it?

Preparing "Dirty Epinephrine" for Emergency Use

"Dirty epinephrine" refers to diluting standard 1:1,000 (1 mg/mL) epinephrine with normal saline at the bedside to create a 1:10,000 (0.1 mg/mL) concentration for intravenous bolus administration in perioperative anaphylaxis and other emergency situations. 1

Preparation Method

To prepare dirty epinephrine, draw up 1 mL of 1:1,000 epinephrine (1 mg) and add 9 mL of normal saline to create 10 mL of 1:10,000 solution (0.1 mg/mL). 2 This yields a final concentration of 100 mcg/mL, which allows for precise titration of small IV bolus doses. 1

Key Preparation Points:

• Start with standard 1 mg/mL epinephrine ampules (already 1:1,000 concentration) 3
• Use normal saline as the diluent—never mix with sodium bicarbonate or alkaline solutions, as these inactivate epinephrine 4
• The resulting 1:10,000 solution contains 0.1 mg/mL or 100 mcg/mL 2
• Prefilled syringes of 100 mcg/mL epinephrine are commercially available in some countries (UK, France, USA) but not universally 1

Final Concentration

The final concentration is 1:10,000 or 100 mcg/mL (0.1 mg/mL). 1, 2 This allows each 1 mL to contain 100 mcg of epinephrine, facilitating accurate dosing of the small IV boluses recommended for graded anaphylaxis.

Three Clinical Examples for Use

1. Grade II Perioperative Anaphylaxis (Moderate Hypotension or Bronchospasm)

Initial IV bolus: 20 mcg (0.2 mL of dirty epinephrine) 1

• Administer when vasopressor or bronchodilator is clinically indicated 1
• If unresponsive at 2 minutes, escalate to 50 mcg 1
• Simultaneously give crystalloid 500 mL rapid bolus, repeat as needed 1
• This small initial dose (20 mcg) is difficult to measure accurately without the 1:10,000 dilution 1

2. Grade III Perioperative Anaphylaxis (Life-Threatening Hypotension or Bronchospasm)

Initial IV bolus: 50-100 mcg (0.5-1.0 mL of dirty epinephrine) 1

• Give 50 mcg if no other vasopressors/bronchodilators have been administered 1
• Give 100 mcg if patient is unresponsive to other vasopressors/bronchodilators 1
• If unresponsive at 2 minutes, escalate to 200 mcg 1
• Administer crystalloid 1 L as rapid bolus, repeat if inadequate response 1

3. Refractory Anaphylaxis Requiring Epinephrine Infusion

Bridge to infusion: Use dirty epinephrine for repeated boluses while preparing continuous infusion 1

• After inadequate sustained response at 10 minutes, escalate by doubling the bolus dose 1
• Consider IM epinephrine 500 mcg while infusion is being prepared 1
• Commence epinephrine infusion (0.05-0.1 mcg/kg/min) peripherally if more than three boluses administered 1
• The 1:10,000 concentration allows precise titration during this critical transition period 1

Critical Pitfalls to Avoid

Do not confuse 1:1,000 with 1:10,000 concentration—using undiluted 1:1,000 IV would deliver 10 times the intended dose. 2 This is the most dangerous error in epinephrine administration.

Familiarity with dilution methods must be part of perioperative anaphylaxis training and included in cognitive aids. 1 The preparation should be practiced regularly, not attempted for the first time during an emergency.

Address hypovolemia with aggressive crystalloid boluses concurrent with epinephrine administration—vasoconstriction without adequate volume resuscitation causes severe organ hypoperfusion despite "normal" blood pressure. 1, 5