Racemic Epinephrine Pediatric Dose — Respiratory
Racemic epinephrine is a 1:1 mixture of d- and l-epinephrine isomers that acts as a potent alpha- and beta-adrenergic agonist, producing mucosal vasoconstriction and reduction of subglottic edema. It is used primarily in pediatric patients for the relief of moderate-to-severe upper airway obstruction, most commonly in croup (laryngotracheobronchitis). It may also be considered in other causes of stridor and upper airway edema in the acute care setting.
Pediatric Dosing
Racemic epinephrine is administered as a nebulized solution using 2.25% racemic epinephrine diluted in 2.5 mL normal saline. Dosing is weight- and age-based rather than strict per-kilogram:
- Infants and small children: 0.25 mL of 2.25% racemic epinephrine in 2.5 mL saline via nebulizer
- Older children: 0.5 mL of 2.25% racemic epinephrine in 2.5 mL saline via nebulizer
For reference, 3 mL of 1:1000 (L-)epinephrine is approximately equivalent to 0.25 mL of 2.25% racemic epinephrine and may be used as an alternative when racemic epinephrine is unavailable. Consult institutional protocol for repeat dosing intervals and maximum number of treatments.
Indications and Clinical Context
Racemic epinephrine is indicated for moderate-to-severe croup (laryngotracheobronchitis) presenting with significant stridor at rest, increased work of breathing, or impending respiratory failure. It is a well-established component of acute croup management alongside systemic corticosteroids (e.g., dexamethasone). By inducing alpha-adrenergic–mediated mucosal vasoconstriction, it reduces subglottic edema and transiently relieves upper airway obstruction. It may also be used for other causes of acute upper airway edema in the pediatric emergency or intensive care setting.
Clinicians should be aware of the rebound phenomenon: symptomatic improvement is temporary (typically 1–2 hours), and patients treated with racemic epinephrine generally require a period of observation (commonly 2–4 hours) to ensure symptoms do not return to baseline or worsen. Discharge decisions should incorporate corticosteroid administration and clinical trajectory per institutional and standard pediatric guidelines.
Administration and Monitoring
Administer via a standard small-volume nebulizer with a well-fitting mask or mouthpiece. Continuous pulse oximetry and clinical monitoring for work of breathing, stridor, and heart rate are recommended during and after treatment. Key considerations include:
- Nebulization is the only indicated route for this indication; do not administer IV or IM for croup management
- Monitor for tachycardia and pallor, which are expected transient adrenergic effects
- Use with caution in patients with underlying cardiac arrhythmias or congenital heart disease
- Observe for rebound symptoms following the treatment period; consult institutional protocol for observation duration and repeat dosing criteria
- L-epinephrine 1:1000 (3 mL nebulized) is an accepted alternative when 2.25% racemic epinephrine is unavailable
Disclaimer: This article is an educational reference summarizing standard pediatric dosing values. It is not a substitute for clinical judgment. Always verify doses against institutional protocols, the current edition of authoritative references (e.g., Lexicomp, Harriet Lane Handbook, PALS guidelines), the patient’s accurate weight, and any patient-specific factors (renal/hepatic function, allergies, comedications) before administration.