Can dexamethasone (intramuscular (IM)) or epinephrine (intramuscular (IM)) be administered to a 5-year-old patient with croup?

Intramuscular Administration for Croup Treatment

Yes, both dexamethasone and epinephrine can be administered intramuscularly to a 5-year-old with croup, and this is well-supported by clinical evidence.

Dexamethasone IM Administration

Intramuscular dexamethasone at 0.6 mg/kg is the mainstay treatment for severe croup and is highly effective. 1

• The standard dose is 0.6 mg/kg administered intramuscularly, with onset of action approximately 6 hours after administration 1
• Lower doses (0.15 mg/kg) have been shown to be equally effective as the 0.6 mg/kg dose in moderate to severe croup, though the higher dose remains the traditional recommendation 2
• IM dexamethasone is as effective as oral or nebulized formulations, with the choice depending on the clinical situation and patient's ability to tolerate oral medication 3
• The IM route is particularly useful when the child cannot tolerate oral medication due to respiratory distress or vomiting 4

Epinephrine IM Administration

While nebulized epinephrine is the standard route for croup, intramuscular epinephrine is NOT typically used for croup treatment. The evidence provided focuses on IM epinephrine for anaphylaxis, not croup. 5

Critical Distinction:

• For croup: Nebulized racemic epinephrine (0.5 mL of 2.25% solution diluted in 2.5 mL saline) is the appropriate formulation and route 4
• For anaphylaxis: IM epinephrine (0.01 mg/kg, maximum 0.3 mg) in the lateral thigh is the preferred route 5

Nebulized Epinephrine for Croup:

• Quickly reverses airway obstruction in children with croup 1
• Requires monitoring for rebound airway obstruction for at least 2 hours after administration 1
• Lower doses (0.1 mg/kg) are non-inferior to conventional doses (0.5 mg/kg) for nebulized l-epinephrine in moderate to severe croup 6
• Children requiring two epinephrine nebulization treatments should be hospitalized 4

Clinical Algorithm for Croup Treatment

For moderate to severe croup in a 5-year-old:

1. Administer dexamethasone 0.6 mg/kg IM (can also use oral route if child can tolerate) 1, 4
2. If significant respiratory distress: Give nebulized racemic epinephrine 0.5 mL of 2.25% solution in 2.5 mL saline 4
3. Provide humidified air (maintain at least 50% relative humidity) 1
4. Monitor for 2 hours after epinephrine nebulization for rebound obstruction 1
5. Consider hospitalization if two epinephrine treatments are required 4

Important Caveats:

• The onset of dexamethasone action is delayed (approximately 6 hours), so nebulized epinephrine provides rapid relief until steroids take effect 1
• Do not confuse IM epinephrine for anaphylaxis with nebulized epinephrine for croup—these are different clinical scenarios requiring different routes of administration 5, 1
• Antihistamines, decongestants, and antibiotics have no proven effect on uncomplicated viral croup 4