Nebulized Adrenaline Dosing
For croup in children, administer 0.5 mL/kg of 1:1000 L-epinephrine (maximum 5 mL) diluted in normal saline, or alternatively use 0.05 mL/kg of 2.25% racemic epinephrine (maximum 0.5 mL) in 2 mL normal saline. 1, 2, 3
Pediatric Croup (Primary Indication)
Standard Dosing Options
L-Epinephrine (1:1000):
- Dose: 0.5 mL/kg up to maximum 5 mL diluted in normal saline for nebulization 1, 2
- This is the preferred formulation when racemic epinephrine is unavailable 1
- Recent evidence suggests a lower dose of 0.1 mg/kg (maximum 1 mg) may be non-inferior to the conventional 0.5 mg/kg dose, though the higher dose remains standard 4
Racemic Epinephrine (2.25%):
- Dose: 0.05 mL/kg (maximum 0.5 mL) in 2 mL normal saline 1, 3
- Many institutions use a simplified protocol of 0.5 mL for all patients regardless of weight 1, 3
Critical Management Points
Observation Requirements:
- Observe patients for 2-3 hours after administration to monitor for symptom rebound, as the effect is transient (1-2 hours duration) 1, 2
- Never discharge patients shortly after nebulized epinephrine due to rebound risk 2
Admission Criteria:
- Consider admission if 3 or more doses are required 1, 2
- Older protocols recommended admission after 2 doses, but quality improvement data shows up to 3 doses can be given safely before admission, reducing hospitalizations by 37-57% without adverse outcomes 1
Combination Therapy:
- Always administer with systemic corticosteroids (dexamethasone 0.6 mg/kg) for optimal croup management 2, 4
Acute Severe Asthma (Alternative Indication)
Nebulized Epinephrine Dosing
For adults with acute severe asthma:
- 1-3 mg of epinephrine via nebulizer has been studied and shown equivalent efficacy to selective β2-agonists 5, 6, 7
- One trial used 2 mg over 10 minutes with comparable results to salbutamol 5 mg 6
- Another trial used 3 mg over 20 minutes with similar efficacy to terbutaline 5 mg 7
Subcutaneous Alternative
- Subcutaneous epinephrine (1:1000): 0.01 mg/kg divided into 3 doses of approximately 0.3 mg at 20-minute intervals 8
- Well-tolerated even in patients >35 years of age, though nonselective adrenergic properties may increase heart rate and myocardial oxygen demand 8
Important Context
Selective β2-agonists (salbutamol/albuterol) remain preferred first-line therapy for acute asthma, as there is no evidence that epinephrine provides superior outcomes compared to inhaled β-agonists 8. Nebulized epinephrine for asthma should be reserved for situations where selective β2-agonists are unavailable or ineffective 5, 6, 7.
Common Pitfalls to Avoid
- Never use 1:1000 epinephrine intravenously - this concentration is only for nebulization, subcutaneous, or intramuscular routes 2
- Do not discharge patients before the 2-3 hour observation period after nebulized epinephrine for croup 1, 2
- Do not use nebulized epinephrine in the home setting due to short duration of action and potential adverse effects 1
- Do not use routinely for bronchiolitis - the American Academy of Pediatrics does not support this practice among inpatients 1
- Verify concentration when dosing - 2.25% racemic epinephrine requires different dosing (0.05 mL/kg max 0.5 mL) than 1:1000 L-epinephrine (0.5 mL/kg max 5 mL) 1, 3