What is the recommended intravenous dose of epinephrine for treating bronchospasm?

Intravenous Epinephrine Dosing for Bronchospasm

For bronchospasm, the recommended initial intravenous dose of epinephrine for adults is 50 μg (0.5 mL of 1:10,000 solution), which may need to be repeated if bronchospasm persists. 1

Adult Dosing

• Initial dose: 50 μg IV (0.5 mL of 1:10,000 solution)
• Several doses may be required for severe or persistent bronchospasm
• If multiple doses are needed, consider starting an IV infusion

IV Infusion Options

• For continuous infusion: Prepare a 1:100,000 solution (1 mg in 100 mL saline)
• Initial infusion rate: 30-100 mL/hr (5-15 μg/min)
• Titrate based on clinical response and side effects 1

Pediatric Dosing

• Initial dose: 0.01 mg/kg (0.1 mL/kg of 1:10,000 solution; maximum 0.3 mg) 1
• Alternative calculation using "rule of 6":
  • 0.6 × body weight (kg) = mg of epinephrine
  • Dilute to total 100 mL of saline
  • 1 mL/hr delivers 0.1 μg/kg/min 1
• Titrate to response, starting with 1 μg/kg
• Children often respond to as little as 1 μg/kg 1

Important Considerations

Monitoring Requirements

• Continuous cardiac monitoring is essential
• Frequent blood pressure measurements
• Pulse oximetry
• If monitoring equipment is unavailable, use every-minute vital sign checks and ECG monitoring if available 1, 2

Precautions

• IV epinephrine carries risk of potentially lethal arrhythmias
• Should be administered IV only in:
  1. Cardiac arrest situations
  2. Profoundly hypotensive patients who failed to respond to IV fluids and IM epinephrine 1
• For severe cases with cardiopulmonary arrest, higher doses may be required:
  • 1-3 mg (1:10,000) slowly IV over 3 minutes
  • Followed by 3-5 mg IV over 3 minutes
  • Then 4-10 μg/min infusion 2

Alternative Treatments for Bronchospasm

• For bronchospasm resistant to epinephrine:
  • Nebulized albuterol 2.5-5 mg in 3 mL saline, repeated as necessary 1
  • Consider IV salbutamol infusion
  • Consider IV aminophylline or magnesium sulfate 1

Clinical Pearls

• Epinephrine is both an alpha and beta-agonist, providing bronchodilation and reducing mediator release 1
• Delayed administration is associated with increased morbidity and mortality 2
• Common mistakes include incorrect route of administration, incorrect injection site, and underdosing 2
• There are no absolute contraindications to epinephrine use in anaphylaxis, even in elderly patients or those with cardiovascular disease 2

Remember that while this guidance focuses on IV epinephrine for bronchospasm, the intramuscular route is preferred for initial treatment of anaphylaxis in most settings, with IV administration reserved for specific critical situations under appropriate monitoring.