What are the indications for epinephrine (adrenaline) administration?

Indications for Epinephrine Administration

Epinephrine is indicated for anaphylaxis (systemic allergic reactions with hypotension, airway swelling, or breathing difficulty), cardiac arrest, septic shock with hypotension, and induction of mydriasis during intraocular surgery. 1, 2

Primary Indications

Anaphylaxis (First-Line Treatment)

Epinephrine should be administered early by intramuscular injection to all patients with signs of systemic allergic reaction, especially hypotension, airway swelling, or difficulty breathing. 3

• Anaphylaxis is confirmed by acute onset with skin/mucosal involvement plus respiratory compromise or hypotension/syncope, or two or more organ systems involved after allergen exposure (skin, respiratory, cardiovascular, gastrointestinal). 4
• Isolated hypotension after known allergen exposure alone can indicate anaphylaxis. 4
• Skin signs may be absent in 10% of anaphylaxis cases—do not wait for urticaria to treat. 4
• Epinephrine is the cornerstone of anaphylaxis treatment and may be lifesaving. 3

Cardiac Arrest

In cardiac arrest secondary to anaphylaxis, standard resuscitative measures and immediate administration of epinephrine should take priority. 3

• Standard ACLS dosing applies: 1 mg IV/IO every 3-5 minutes during resuscitation. 3
• For cardiac arrest from any cause, epinephrine 0.01 mg/kg of 1:10,000 solution (maximum 1 mg) is recommended for older infants/children, repeated every 3-5 minutes. 3

Septic Shock with Hypotension

Epinephrine is indicated to increase mean arterial blood pressure in adult patients with hypotension associated with septic shock. 1, 2

• Administered as IV infusion at 0.05 to 2 mcg/kg/min, titrated to achieve desired blood pressure. 1, 2
• Requires dilution in dextrose solution and infusion into a large vein. 1, 2

Intraocular Surgery

Epinephrine is indicated for induction and maintenance of mydriasis during intraocular surgery. 1

• Dilute 1 mL with 100 to 1000 mL of ophthalmic irrigation fluid for irrigation or intracameral injection. 1

Secondary/Adjunctive Indications

Severe Asthma Exacerbation

• Subcutaneous epinephrine 0.01 mg/kg of 1:1000 solution (maximum 0.3-0.5 mg) may be used, repeated every 20 minutes up to 3 doses. 3
• However, international asthma guidelines recommend against epinephrine in acute asthma unless associated with anaphylaxis or angioedema. 3
• Begin simultaneous treatment with inhaled β-agonist (albuterol) and corticosteroids. 3

Laryngotracheobronchitis (Croup)

• Nebulized epinephrine: 0.5 mL/kg of 1:1000 solution (maximum 5 mL) administered by nebulizer. 3
• Racemic epinephrine 2.25% solution: 0.05 mL/kg (maximum 0.5 mL) in 2 mL normal saline by nebulizer. 3

Refractory Shock After Volume Resuscitation

• IV infusion at 0.1-1.0 mcg/kg/min in children, starting at lowest dose and titrating to clinical effect (doses up to 5 mcg/kg/min sometimes necessary). 3
• For adults, continuous infusion of 5-15 mcg/min may be used for anaphylactic shock unresponsive to boluses. 3

Critical Route and Dosing Distinctions

Intramuscular Route (Preferred for Anaphylaxis)

Intramuscular injection into the lateral thigh (vastus lateralis) is the preferred route for anaphylaxis due to ease of administration, effectiveness, and safety. 3

• Adults: 0.2-0.5 mg (1:1000 concentration), repeated every 5-15 minutes as needed. 3
• Children >30 kg: 0.3-0.5 mg. 1
• Children <30 kg: 0.01 mg/kg (maximum 0.3 mg). 3, 1
• IM injection in the thigh achieves peak plasma concentrations in 8±2 minutes versus 34±14 minutes with subcutaneous deltoid injection. 4

Intravenous Route (Reserved for Specific Situations)

IV epinephrine should only be used for cardiac arrest, profoundly hypotensive patients failing multiple IM doses and volume replacement, or septic shock. 3, 4

• For anaphylactic shock with IV access: 0.05-0.1 mg (1:10,000 concentration). 3
• The risk of overdose and adverse cardiovascular events is significantly higher with IV bolus epinephrine (10% vs 1.3% for IM; odds ratio 8.7). 5
• All overdoses in one study occurred with IV bolus administration. 5
• IV epinephrine carries significant risk of dilution/dosing errors and serious adverse effects. 4

Common Pitfalls to Avoid

Concentration Confusion

Always use 1:1000 (1 mg/mL) for IM/subcutaneous injection; 1:10,000 (0.1 mg/mL) is reserved for IV use only. 4

• Confusion about epinephrine dosing has led to iatrogenic overdoses causing transient severe systolic dysfunction and potentially lethal cardiac complications. 6
• Six of seven surveyed hospitals did not stock prefilled IM dose syringes for emergency anaphylaxis use, increasing error risk. 6

Delayed Administration

Fatalities during anaphylaxis result from delayed epinephrine administration—there is no absolute contraindication to epinephrine in anaphylaxis. 3

• Approximately 200 Americans die from anaphylaxis annually, mostly from medication reactions. 3
• The risk of death from untreated anaphylaxis far exceeds the risk of epinephrine-related adverse effects, even in elderly patients or those with cardiac disease. 4

Route Selection Errors

Never inject epinephrine into buttocks, digits, hands, or feet due to risk of local necrosis and ischemia. 1

• Avoid extravasation into tissues, which can cause local necrosis. 3, 1, 2
• If extravasation occurs, phentolamine 0.1-0.2 mg/kg (up to 10 mg) diluted in 10 mL normal saline injected intradermally at the site may counteract dermal vasoconstriction. 3

Inadequate Repeat Dosing

Approximately 10-20% of patients require more than one dose of epinephrine, with recurrence of symptoms after 5-15 minutes commonly reported. 3, 4

• There is no maximum number of IM epinephrine doses for anaphylaxis—repeat every 5 minutes as needed until symptoms resolve. 4
• Most patients require 1-2 doses, but some need more. 4