Stridor at Rest Marks Severe Croup
Stridor without agitation signals severe upper-airway narrowing.
- At rest: Severity marker (stridor present without crying)
- Subglottic edema: Cause (viral laryngotracheobronchitis)
- Nebulized epi: Action (plus systemic steroid)
- Monitored ED: Setting (close observation required)
Recognizing severe croup
Placeholder: stridor at rest plus retractions indicates severe airway obstruction.
Nebulized Epinephrine Delivery
Aerosol mist carries epinephrine directly onto airway mucosa.
- Nebulized: Route (face mask aerosol)
- ~10 min: Onset (rapid topical action)
- Racemic/L-epi: Drug (alpha and beta agonist)
- As needed: Dose repeat (per protocol, monitored)
Delivery mechanics
Placeholder: mist particles deposit epinephrine onto inflamed subglottic mucosa.
Rapid Mucosal Vasoconstriction
Alpha-adrenergic action shrinks swollen vessel walls quickly.
- Alpha-1 agonism: Mechanism (vascular smooth muscle)
- Reduced edema: Effect (mucosal fluid shift out)
- Minutes: Speed (fast topical response)
- ~2 hr: Duration (effect gradually fades)
Vessel-level effect
Placeholder: constricted capillaries reduce mucosal fluid leakage and swelling.
Temporary Airway Widening
Lumen widens as swelling drops, peaking near thirty minutes.
- ~30 min: Peak time (maximal lumen widening)
- Stridor eases: Symptom change (improved air entry)
- ~1–2 hr: Duration (temporary, not curative)
- Not a cure: Caution (underlying edema persists)
Peak widening window
Placeholder: airway diameter improves temporarily while drug effect lasts.
Rebound Edema — Observation Period
Swelling can return once epinephrine effect wears off.
- 2–4 hr: Risk window (after nebulization)
- Min. 3–4 hr: Observation (monitored stay recommended)
- Reassess stridor: Action (may repeat dose or admit)
- If stable: Discharge (no stridor at rest, no retraction)
Why observation matters
Placeholder: rebound edema can recur without lasting steroid coverage.
Placeholder: always observe for rebound before discharge.