Epinephrine in Pediatric Emergencies
Epinephrine (adrenaline) is one of the most critical medications in pediatric emergency medicine. It is an endogenous catecholamine that acts on both alpha and beta adrenergic receptors, producing vasoconstriction, bronchodilation, increased heart rate, and increased myocardial contractility. These properties make it indispensable in the management of cardiac arrest, anaphylaxis, and severe upper airway obstruction.
Correct dosing of epinephrine in children is paramount because the therapeutic window is narrow. Underdosing may fail to produce the desired physiological response, while overdosing can cause dangerous hypertension, tachyarrhythmias, and myocardial ischemia. The dose, concentration, and route all vary depending on the clinical indication.
One of the most common and potentially fatal errors in pediatric resuscitation is confusing epinephrine concentrations (1:1,000 vs. 1:10,000). This calculator helps clarify the correct concentration and volume for each clinical scenario.
Dosing by Indication and Route
| Indication | Route | Dose (mg/kg) | Concentration | Max Dose |
|---|---|---|---|---|
| Cardiac Arrest | IV / IO | 0.01 mg/kg | 1:10,000 (0.1 mg/mL) | 1 mg |
| Cardiac Arrest | Endotracheal | 0.1 mg/kg | 1:1,000 (1 mg/mL) | 2.5 mg |
| Anaphylaxis | IM (anterolateral thigh) | 0.01 mg/kg | 1:1,000 (1 mg/mL) | 0.5 mg |
| Anaphylaxis | IV / IO (refractory) | 0.001 mg/kg infusion | 1:10,000 (0.1 mg/mL) | Titrate to effect |
| Croup / Stridor | Nebulizer | 0.5 mL/kg of 1:1,000 | 1:1,000 (1 mg/mL) | 5 mL |
Understanding Epinephrine Concentrations
Epinephrine concentrations are expressed as ratios, which can be confusing. Understanding the difference is critical to patient safety:
| Ratio | Concentration | mg per mL | Primary Use |
|---|---|---|---|
| 1:1,000 | 1 mg/mL | 1.0 mg/mL | IM injection (anaphylaxis), nebulization, ETT |
| 1:10,000 | 0.1 mg/mL | 0.1 mg/mL | IV/IO injection (cardiac arrest, resuscitation) |
Key safety point: The 1:10,000 concentration is 10 times more dilute than 1:1,000. If 1:1,000 is accidentally given IV at the IV dose volume, the patient receives 10 times the intended dose, which can be fatal. Many institutions now use mg/mL labeling exclusively to reduce confusion.
Emergency Dosing Algorithm
Anaphylaxis Management in Children
Anaphylaxis is a severe, life-threatening systemic hypersensitivity reaction that requires immediate treatment with epinephrine. In children, the most common triggers include food allergens (peanuts, tree nuts, milk, eggs), insect stings, and medications.
- First-line treatment: Intramuscular epinephrine in the anterolateral thigh (vastus lateralis) is the gold standard. It should be administered as soon as anaphylaxis is recognized — do not wait for progression of symptoms.
- Dose: 0.01 mg/kg of 1:1,000 (1 mg/mL) solution, maximum 0.3 mg for prepubertal children, 0.5 mg for adolescents and adults.
- Repeat dosing: May be repeated every 5–15 minutes if symptoms persist or recur. Most patients respond to one or two doses.
- Position: Place the patient supine with legs elevated unless there is respiratory distress or vomiting, in which case allow the patient to sit upright.
- Adjunct therapies: IV fluids for hypotension (20 mL/kg NS bolus), albuterol for bronchospasm, antihistamines (H1 and H2 blockers), and corticosteroids. These are second-line and should never delay epinephrine administration.
- Observation period: After treatment, observe for at least 4–6 hours due to risk of biphasic reaction (recurrence of symptoms hours after initial resolution).
Auto-Injectors (EpiPen)
Epinephrine auto-injectors are pre-filled devices designed for self-administration or caregiver administration in the field. Two sizes are available:
| Device | Dose | Weight Range | Notes |
|---|---|---|---|
| EpiPen Jr / Auvi-Q 0.15 | 0.15 mg | 15–30 kg | For children approximately 4–12 years old |
| EpiPen / Auvi-Q 0.3 | 0.3 mg | >30 kg | For adolescents and adults |
Limitations of auto-injectors include fixed dosing (no weight-based adjustment), potential needle length issues in very obese or very lean patients, and the need for proper training in use. All patients with a history of anaphylaxis should carry two auto-injectors at all times and have an anaphylaxis action plan.
Worked Example
A 20 kg child in cardiac arrest requiring IV/IO epinephrine:
Maximum dose is 1 mg. The calculated dose of 0.2 mg is within range. Administer 2.0 mL of 1:10,000 epinephrine IV/IO. May repeat every 3–5 minutes per PALS protocol.
Same child with anaphylaxis requiring IM epinephrine:
Administer 0.2 mL of 1:1,000 epinephrine IM in the anterolateral thigh. May repeat every 5–15 minutes if symptoms persist.
Frequently Asked Questions
Why is the IV dose different from the IM dose?
The IV dose is given with 1:10,000 (0.1 mg/mL) concentration because IV administration provides immediate systemic delivery with rapid onset. The IM dose uses 1:1,000 (1 mg/mL) because intramuscular absorption is slower and requires a higher concentration in a smaller volume. The actual mg/kg dose for cardiac arrest (IV) and anaphylaxis (IM) is the same (0.01 mg/kg), but the concentration and clinical context differ.
Can epinephrine be given subcutaneously?
The IM route is preferred over subcutaneous (SC) injection because IM provides faster and more reliable absorption, especially in patients with poor perfusion (such as during anaphylaxis or cardiac arrest). The SC route results in slower and less predictable absorption. Current guidelines from the World Allergy Organization and ACAAI recommend IM injection exclusively.
What if the child weighs less than 10 kg?
For infants and small children under 10 kg, the weight-based calculation still applies. However, the volumes become very small and precise measurement is critical. Use a 1 mL syringe for accurate measurement. For example, a 5 kg infant in cardiac arrest would receive 0.05 mg = 0.5 mL of 1:10,000 solution IV/IO.
How is nebulized epinephrine used for croup?
Nebulized racemic epinephrine (0.05 mL/kg of 2.25% solution, max 0.5 mL) or L-epinephrine (0.5 mL/kg of 1:1,000, max 5 mL) is used for moderate-to-severe croup (stridor at rest). The medication is delivered via nebulizer over 15 minutes. Patients must be observed for at least 2–4 hours after nebulization due to the risk of rebound worsening.