Nebulized Adrenaline: Clinical Indications
Nebulized adrenaline is primarily indicated for croup in children to avoid intubation and stabilize patients prior to intensive care transfer, but should not be used for outpatient management due to its short-lived effect. 1
Primary Indication: Croup
Nebulized adrenaline (0.5 ml/kg of a 1:1000 solution) is the standard treatment for moderate to severe croup to temporarily relieve upper airway obstruction through vasoconstriction and reduction of mucosal edema. 1, 2
Key Clinical Parameters:
- Dosing: 0.05 mL/kg of 2.25% racemic epinephrine solution (maximum 0.5 mL) in 2 mL normal saline, or alternatively L-epinephrine 1:1000 at 0.5 mL/kg up to 5 mL if racemic form unavailable 2
- Duration of effect: 1-2 hours only 1
- Observation period: Patients must be observed for 2-3 hours after administration to monitor for symptom rebound 2
- Admission criteria: Consider admission if 3 or more doses required in the emergency department 2
Critical Contraindications:
- Never use for outpatient or home management due to short duration of action and rebound risk 1, 2
- Do not discharge shortly after administration without adequate observation period 1
Secondary Indication: Post-Intubation Stridor
Nebulized adrenaline may be used to manage stridor following endotracheal intubation in children. 1
Acute Severe Asthma (Limited Role)
Nebulized adrenaline is NOT routinely recommended for acute asthma, as selective β2-agonists (salbutamol/albuterol) are equally effective with fewer side effects. 3, 4, 5
When to Consider in Asthma:
- Concomitant anaphylaxis or angioedema - this is the primary exception where epinephrine becomes first-line 3
- Life-threatening asthma unresponsive to repeated inhaled β2-agonists in prehospital settings where selective agents are unavailable 3
- Patients unable to cooperate with inhaled therapy 2
Dosing for Asthma (if used):
- Adults: 1-3 mg via nebulizer (studies used 2 mg over 10 minutes or 3 mg over 20 minutes) 2, 4, 5
- Alternative: Subcutaneous epinephrine 1:1000 at 0.01 mg/kg in 3 doses of approximately 0.3 mg at 20-minute intervals 3, 2
Important Caveats for Asthma Use:
- Epinephrine and selective β2-agonists show equivalent efficacy with pooled odds ratio for treatment failure of 0.99 (95% CI 0.75-1.32) 3
- Worse side effect profile including increased heart rate, myocardial irritability, and increased oxygen demand 3
- Quality of evidence is low with significant heterogeneity among studies 3
- International asthma guidelines recommend against routine use except with anaphylaxis 3
Anaphylaxis (Intramuscular Route Preferred)
While the question asks about nebulized adrenaline, it's critical to note that intramuscular adrenaline into the lateral thigh is the cornerstone of anaphylaxis management, not the nebulized route. 6, 7 Nebulized administration is not the standard approach for anaphylaxis.
NOT Indicated: Bronchiolitis
Do not use nebulized adrenaline routinely for bronchiolitis in hospitalized infants, as it is not supported by evidence. 2
Clinical Decision Algorithm
Croup with moderate-severe symptoms → Nebulized adrenaline 0.5 ml/kg of 1:1000 solution + observe 2-3 hours 1, 2
Acute severe asthma → First-line: Inhaled selective β2-agonists (salbutamol) + systemic corticosteroids + oxygen 3, 8
- Only consider epinephrine if: anaphylaxis present OR life-threatening features unresponsive to β2-agonists 3
Post-intubation stridor → Nebulized adrenaline may be considered 1
Anaphylaxis → Intramuscular (NOT nebulized) adrenaline is the treatment of choice 6, 7