Epinephrine Dosing and Administration in Medical Emergencies
For anaphylaxis, administer 0.2-0.5 mg of epinephrine (1:1000 concentration) intramuscularly into the anterolateral thigh immediately, repeating every 5-15 minutes as needed; for cardiac arrest, give 1 mg IV/IO (1:10,000 concentration) every 3-5 minutes during ongoing resuscitation. 1, 2
Anaphylaxis Management
Initial Treatment
- Intramuscular epinephrine is the first-line, life-saving intervention with no absolute contraindications 1, 3
- Inject into the anterolateral aspect of the mid-thigh (vastus lateralis muscle), which produces the most rapid peak plasma concentrations 1, 2, 4
- Adult dose: 0.2-0.5 mg (0.2-0.5 mL of 1:1000 solution) 1, 2
- Pediatric dose: 0.01 mg/kg (maximum 0.3 mg for children <30 kg, 0.5 mg for children ≥30 kg) 5, 2
- Repeat every 5-15 minutes as needed until symptoms resolve 1, 2
Critical Safety Point
Never inject epinephrine into the buttocks, digits, hands, or feet due to risk of tissue necrosis 2. The intramuscular route is preferred over subcutaneous because of faster onset of action 4.
Intravenous Route (When IV Access Already Established)
- Use only 0.05-0.1 mg (5-10 mL of 1:10,000 solution) for anaphylactic shock 1, 5
- This is 5-10% of the cardiac arrest dose to avoid severe hypertension and cardiac complications 5
- IV infusion is a reasonable alternative to boluses in non-arrest anaphylaxis 1
Common Medication Error
A critical safety concern exists: physicians frequently confuse anaphylaxis dosing (1:1000 IM) with cardiac arrest dosing (1:10,000 IV), leading to potentially lethal 10-fold overdoses 6, 7. Only 16.8% of junior doctors in one survey knew the correct dose and route 7. Hospitals should stock clearly labeled, pre-filled intramuscular syringes that are easily distinguished from IV formulations 5, 6.
Cardiac Arrest Management
Standard Dosing
- 1 mg IV/IO every 3-5 minutes during ongoing cardiac arrest 5
- Use 1:10,000 concentration (0.1 mg/mL) for IV/IO administration 5
- Continue throughout resuscitation efforts until return of spontaneous circulation or termination of efforts 1
Anaphylaxis-Induced Cardiac Arrest
If anaphylaxis progresses to cardiac arrest, immediately switch to cardiac arrest protocols with standard resuscitative measures and 1 mg IV/IO epinephrine every 3-5 minutes 1, 5. Standard BLS and ACLS take priority, including airway management 1.
Monitoring and Adjunctive Care
Essential Monitoring
- Close hemodynamic monitoring is mandatory in anaphylactic shock, as cardiovascular and respiratory status can deteriorate rapidly 1, 5
- Establish large-bore IV access immediately 3
- Administer 100% oxygen to all patients with respiratory distress 3
- Give rapid IV fluid boluses with normal saline or lactated Ringer's 3
Airway Management
Refer immediately to a provider with advanced airway expertise (including surgical airway capability) given the potential for rapid oropharyngeal or laryngeal edema 1. This is a Class I recommendation from the American Heart Association 1.
What NOT to Do
Do not give antihistamines or corticosteroids before or instead of epinephrine 3. These agents have no role in acute anaphylaxis management due to slow onset of action and lack of proven benefit during anaphylaxis-induced cardiac arrest 1, 3.
Post-Event Care
Observation Period
- Observe for at least 4 hours after symptom resolution 3
- Extend to 24 hours for severe reactions or those requiring more than one epinephrine dose 3
- Biphasic reactions can occur, necessitating prolonged monitoring 3
Discharge Planning
Prescribe an epinephrine auto-injector (0.3 mg for adults/children >30 kg; 0.15 mg for children 15-30 kg) with detailed instructions for home use 1, 5, 3.
Special Populations and Precautions
High-Risk Patients
Epinephrine may aggravate conditions in patients with underlying heart disease, hyperthyroidism, Parkinson's disease, diabetes, or pheochromocytoma, but the presence of these conditions should never deter use in anaphylaxis 2. The risk of death from untreated anaphylaxis far exceeds the risk of epinephrine administration 2.
Sulfite Sensitivity
The presence of sulfite preservatives in epinephrine formulations should not deter use for anaphylaxis 1.