What considerations should be taken before administering an epinephrine (adrenaline) infusion?

Pre-Administration Considerations for Epinephrine Infusion

Epinephrine infusion should only be administered after failure of multiple intramuscular epinephrine injections and aggressive volume resuscitation, and is reserved for profoundly hypotensive patients in cardiac arrest or refractory shock—never as first-line therapy. 1

Critical Pre-Administration Requirements

Volume Resuscitation Must Come First

• Administer large-volume crystalloid boluses (1-2 L for adults, up to 30 mL/kg in first hour for children) before or concurrent with epinephrine infusion 1
• Failure to adequately volume resuscitate before starting epinephrine causes severe organ hypoperfusion despite "normal" blood pressure due to vasoconstriction in a hypovolemic state 1
• Normal saline should be infused at 5-10 mL/kg in the first 5 minutes for adults 1

Confirm Failure of Standard Therapy

• Epinephrine infusion is indicated only after several intramuscular epinephrine injections (0.3-0.5 mg every 5 minutes) have failed to control symptoms 1
• The risk of potentially lethal arrhythmias means IV epinephrine should be reserved for cardiac arrest or profound hypotension unresponsive to IM injections and IV fluids 1

Vascular Access and Monitoring Setup

Route of Administration

• Infuse epinephrine into a large vein—central venous access is strongly preferred when available 1, 2
• Avoid extravasation into tissues, which causes local necrosis and potential gangrene 2
• Check the infusion site frequently for free flow; blanching along the vein may indicate vasa vasorum constriction 2
• Avoid ankle vein infusions due to risk of lower extremity gangrene 2

Monitoring Requirements

• Continuous hemodynamic monitoring is essential when available (emergency department or ICU setting) 1
• If formal monitoring unavailable but infusion deemed essential, monitor by every-minute blood pressure and pulse measurements plus electrocardiographic monitoring if available 1
• Monitor for signs of excessive vasoconstriction: cold extremities, decreased urine output, cardiac arrhythmias 2

Preparation and Dosing Specifications

Standard Adult Concentration

• Prepare by adding 1 mg (1 mL of 1:1000 dilution) to 250 mL of D5W to yield 4.0 mcg/mL 1
• Infuse at 1-4 mcg/min (15-60 drops/min with microdrop apparatus), increasing to maximum 10 mcg/min 1
• Alternative preparation: 1 mg in 100 mL saline (1:100,000 solution) administered at 30-100 mL/h (5-15 mcg/min), titrated based on response 1

Pediatric Dosing

• Recommended dose: 0.01 mg/kg (0.1 mL/kg of 1:10,000 solution; maximum 0.3 mg) 1
• Alternative "rule of 6": 0.6 × body weight (kg) = number of milligrams diluted to 100 mL saline; then 1 mL/h delivers 0.1 mcg/kg/min 1

Patient-Specific Risk Assessment

Cardiovascular Contraindications (Relative)

• There is no absolute contraindication to epinephrine in anaphylaxis, but exercise extreme caution in patients with: 1
  • Coronary artery disease or cardiomyopathy (risk of cardiac arrhythmias and myocardial ischemia) 2
  • Elderly patients (increased risk of intracranial hemorrhage from rapid blood pressure rise) 3
  • Patients on MAO inhibitors or tricyclic antidepressants (risk of severe, prolonged hypertension) 2

Drug Interactions to Consider

• Beta-blockers potentiate hypertensive effects and increase arrhythmogenic potential 2
• Drugs that counter pressor effects: alpha-blockers, nitrates, diuretics, antihypertensives 2
• Halogenated anesthetics, quinidine, and cardiac glycosides increase arrhythmia risk 2

Extravasation Prevention and Management

Prevention Strategies

• Use large veins and check infusion site frequently 2
• Consider changing infusion site at intervals if blanching occurs to allow local vasoconstriction effects to subside 2

Immediate Treatment if Extravasation Occurs

• Infiltrate 10-15 mL of saline containing 5-10 mg phentolamine (adrenergic blocking agent) into affected area 2
• Use fine hypodermic needle and infiltrate liberally throughout the cold, hard, pallid area 2
• Must be done within 12 hours for sympathetic blockade to cause immediate hyperemic changes 2

Special Populations

Sulfite-Sensitive Patients

• Epinephrine injection contains sodium metabisulfite, which may cause allergic reactions including anaphylaxis in susceptible patients 2
• The presence of sulfite should NOT preclude use for life-threatening hypotension, as alternatives may not be satisfactory 2

Pregnancy

• Epinephrine may cause fetal harm, but this must be weighed against maternal life-threatening anaphylaxis 2

Common Pitfalls to Avoid

• Never use epinephrine infusion as first-line therapy—multiple IM injections are safer and equally effective in most cases 1
• Never start epinephrine infusion without aggressive volume resuscitation 1
• Several anaphylaxis fatalities have been attributed to injudicious use of IV epinephrine 1
• Do not confuse 1:1000 with 1:10,000 concentrations—using 1:1000 IV when 1:10,000 indicated delivers 10 times the intended dose 4
• Avoid peripheral administration in ankle veins due to gangrene risk 2