Nebulized Norepinephrine for Croup: Not Recommended
Nebulized norepinephrine (noradrenaline) is NOT an established or recommended treatment for croup—the evidence-based standard is nebulized epinephrine (adrenaline), not norepinephrine. This is a critical distinction, as these are different medications with different pharmacologic properties.
The Correct Medication: Nebulized Epinephrine
Treatment Algorithm for Croup
All children with croup should receive oral dexamethasone (0.15-0.6 mg/kg, maximum 10-12 mg) as first-line treatment regardless of severity 1, 2. The treatment then escalates based on severity:
- Mild croup: Oral dexamethasone alone is sufficient, with 2-3 hours of observation 2
- Moderate to severe croup: Add nebulized epinephrine (0.5 ml/kg of 1:1000 solution, maximum 5 ml) to the corticosteroid regimen 1, 2
Evidence for Nebulized Epinephrine (Not Norepinephrine)
Nebulized epinephrine demonstrates clinically significant symptom reduction at 30 minutes post-treatment (SMD -0.94; 95% CI -1.37 to -0.51) 3. This effect is transient, lasting only 1-2 hours, which necessitates close monitoring 1, 2.
Research comparing low-dose (0.1 mg/kg) versus conventional-dose (0.5 mg/kg) nebulized L-epinephrine found both equally effective for moderate to severe croup 4. There is no significant difference between racemic epinephrine and L-epinephrine formulations 3.
Critical Safety Considerations
Never discharge a child shortly after nebulized epinephrine administration due to the risk of rebound symptoms 1, 2. The mandatory observation period is at least 2 hours after the last dose of nebulized epinephrine 2.
Hospitalization Criteria
Consider admission when:
- Three or more doses of nebulized epinephrine are required (the updated "3 is the new 2" approach reduces hospitalization rates by 37% without increasing adverse outcomes) 1, 2
- Oxygen saturation <92% 1
- Age <18 months 1
- Persistent stridor at rest despite treatment 2
Alternative Corticosteroid Option
If oral administration is not feasible, nebulized budesonide (500-2000 µg or 2 mg) is equally effective as oral dexamethasone 1, 2, 5. However, oral dexamethasone remains the preferred route 6.
Common Pitfalls to Avoid
- Confusing norepinephrine with epinephrine—these are distinct medications; only epinephrine has evidence for croup treatment
- Discharging patients before the 2-hour observation period after nebulized epinephrine 1, 2
- Failing to administer corticosteroids in mild cases 2
- Admitting after only 1-2 doses of epinephrine when a third dose could be safely administered in the ED 1
- Using nebulized treatments in outpatient settings without adequate observation capacity 2