What is the dosage and administration of intravenous (IV) epinephrine (adrenaline) for anaphylactic shock?

Intravenous Epinephrine Dosage for Anaphylactic Shock

For anaphylactic shock, IV epinephrine should be administered at a dose of 0.05 to 0.1 mg (5-10% of the cardiac arrest dose) when IV access is available, followed by continuous infusion at 5-15 μg/min if needed for persistent shock. 1, 2

Initial Management Approach

1. First-line treatment:

   • Intramuscular epinephrine is the preferred initial route (0.3-0.5 mg of 1:1000 solution in the lateral thigh) 1, 2
   • Only switch to IV route when IV access is already established 1

2. IV bolus administration:

   • Dose: 0.05-0.1 mg (equivalent to 0.5-1 mL of 1:10,000 solution) 1, 2
   • This is approximately 5-10% of the dose used in cardiac arrest 1
   • Administer slowly to minimize adverse effects

3. IV continuous infusion:

   • Indicated when shock recurs after initial treatment 1
   • Dosage: 5-15 μg/min 1, 2
   • Allows for careful titration and avoidance of epinephrine overdose 1
   • Requires close hemodynamic monitoring 2

Special Considerations

• Monitoring: Close hemodynamic monitoring is essential as cardiovascular and respiratory status can change rapidly 1, 2

• Airway management: When anaphylaxis causes obstructive airway edema, rapid advanced airway management is critical; emergency cricothyroidotomy or tracheostomy may be required 1, 2

• Fluid resuscitation: Aggressive fluid resuscitation with isotonic crystalloids should accompany epinephrine administration 2

• Refractory cases: For patients on β-blockers with refractory hypotension, consider glucagon (1-5 mg IV over 5 minutes, followed by infusion at 5-15 μg/min) 2

Common Pitfalls to Avoid

1. Delayed administration: Failure to promptly administer epinephrine is associated with increased mortality 3

2. Incorrect route selection: Using subcutaneous instead of intramuscular or IV routes can delay onset of action 4

3. Overreliance on antihistamines: Antihistamines should never replace epinephrine as the initial treatment 2

4. Insufficient fluid resuscitation: Anaphylaxis can cause up to 37% decrease in circulating blood volume 2

5. Inappropriate IV dosing: Using full cardiac arrest doses of epinephrine (1 mg) IV can cause dangerous hypertension, myocardial ischemia, and arrhythmias 1

Evidence Strength

The recommendations for IV epinephrine dosing in anaphylactic shock are based on Class 2a, Level of Evidence C-LD (limited data) according to the American Heart Association guidelines 1. While the evidence quality is not high, there is consensus among major guidelines about the appropriate IV dosing strategy. The 2020 AHA guidelines represent the most recent and authoritative guidance on this topic.