Epinephrine Infusion Rate for Anaphylactic Shock Without Cardiac Arrest
For anaphylactic shock without cardiac arrest requiring continuous epinephrine infusion, start at 0.05-0.1 mcg/kg/min (using 1:10,000 dilution) and titrate upward to clinical effect, with doses potentially reaching 0.5-2 mcg/kg/min in refractory cases.
Initial Bolus Dosing Before Infusion
Before initiating an infusion, administer IV boluses of epinephrine from a 1:10,000 solution:
- Adults: Start with 50 mcg (0.5 mL of 1:10,000), repeat with 100-200 mcg every 2 minutes as needed 1, 2
- Pediatrics: 1 mcg/kg initially, titrating upward (using 0.1 mL/kg of 1:10,000 = 10 mcg/kg prepared dose) 1
Consider starting an infusion when multiple boluses are required (typically after 3 or more doses) or when hypotension persists despite repeated boluses 3, 2.
Continuous Infusion Preparation and Dosing
Preparation of 1:10,000 Infusion
The standard preparation involves:
- Add 1 mg epinephrine (1 mL of 1:1000) to 1000 mL of 5% dextrose or normal saline
- This creates a 1 mcg/mL solution 4
- Alternatively, dilute 10 mL (1 mg) from a pre-filled syringe in 1000 mL 4
Infusion Rate Algorithm
Pediatric dosing 3:
- Start: 0.1 mcg/kg/min
- Titrate: 0.1-1.0 mcg/kg/min for desired effect
- Maximum: Up to 5 mcg/kg/min may be necessary in severe cases
Adult dosing 4:
- Start: 0.05 mcg/kg/min (equivalent to 2 mL/min or 120 mL/h of the 1 mcg/mL solution)
- Titrate: Increase by 0.05-0.2 mcg/kg/min every 10-15 minutes
- Target: 0.05-2 mcg/kg/min to achieve adequate mean arterial pressure
- Maximum: Up to 10 mcg/kg/min (600 mL/h) in refractory shock 4
Alternative consensus recommendations 2:
- Initial rate: 0.05-0.1 mcg/kg/min peripherally
- Commence infusion after more than 3 boluses administered
Critical Management Points
Titration Strategy
Adjust the infusion rate every 10-15 minutes based on:
- Mean arterial pressure (target >65 mmHg in adults, age-appropriate in children)
- Heart rate and cardiac output
- Oxygen saturation
- Resolution of bronchospasm 4
Weaning Protocol
After hemodynamic stabilization 4:
- Decrease incrementally every 30 minutes
- Wean over 12-24 hours
- Monitor closely for recurrence
Route Considerations
- Peripheral IV access is acceptable for infusion initiation 2
- Large vein preferred when possible 4
- Avoid leg veins in elderly or those with vascular disease 4
- Critical caveat: IV infiltration causes severe skin injury; phentolamine 0.1-0.2 mg/kg (max 10 mg) diluted in 10 mL saline can be injected intradermally at extravasation sites 3
Refractory Hypotension Management
If blood pressure remains inadequate despite epinephrine infusion 5, 2:
Add second-line vasopressors:
- Norepinephrine 0.05-0.5 mcg/kg/min
- Vasopressin 1-2 IU bolus ± 2 units/h infusion
- Phenylephrine or metaraminol per institutional protocols
For patients on beta-blockers 5:
- Glucagon 1-5 mg IV over 5 minutes (adults)
- Pediatric: 20-30 mcg/kg (max 1 mg)
- Follow with infusion 5-15 mcg/min
Aggressive fluid resuscitation: Up to 20-30 mL/kg of crystalloid 2
Common Pitfalls to Avoid
Concentration errors are the most dangerous mistake: The 1:10,000 (0.1 mg/mL) dilution is used for IV boluses and infusions in anaphylaxis without cardiac arrest. The 1:1000 (1 mg/mL) concentration is for IM administration only in this context 3. Confusing these concentrations results in 10-fold dosing errors.
Delayed infusion initiation: Don't wait for complete cardiovascular collapse. If a patient requires 3+ boluses or shows persistent hypotension after initial doses, start the infusion promptly 2.
Inadequate monitoring: Continuous hemodynamic monitoring is essential during epinephrine infusions 5. This includes continuous blood pressure, cardiac monitoring, and pulse oximetry.
Premature discontinuation: Observe patients for minimum 6 hours after stabilization due to risk of biphasic reactions 2.