Stridor: Causes, Clinical Significance, and Emergency Management

Stridor is a high-pitched, monophonic sound produced by turbulent airflow through a narrowed extrathoracic (supraglottic/glottic) or intrathoracic airway. It is a sign of partial airway obstruction and a potential medical emergency.

Localization by Phase

• Inspiratory stridor: Extrathoracic obstruction (larynx, trachea above thoracic inlet) – e.g., croup, epiglottitis, laryngomalacia, vocal cord paralysis.
• Expiratory stridor (wheeze): Intrathoracic obstruction (trachea/bronchi within chest) – e.g., tracheomalacia, foreign body, asthma.
• Biphasic: Fixed obstruction (subglottic stenosis, tracheal tumor, foreign body at thoracic inlet).

Common Causes by Age

• Children: Croup (viral), foreign body, epiglottitis (Hib – now rare), bacterial tracheitis, congenital anomalies.
• Adults: Laryngeal edema (angioedema, anaphylaxis, post-extubation), vocal cord dysfunction, tumors, tracheal stenosis, thyroid mass, foreign body.

Emergency Assessment (ABCs)

1. Airway: Assess severity (mild/moderate/severe); prepare for intubation/cricothyrotomy.
2. Breathing: O₂, monitoring, positioning (upright).
3. Circulation: IV access, fluids if needed.
4. Do Not Agitate: Avoid unnecessary exams; keep calm.

Immediate Interventions

• Nebulized epinephrine (croup, post-extubation edema)
• IM epinephrine (anaphylaxis)
• Corticosteroids (dexamethasone – croup, edema)
• Heliox (temporizing)
• Definitive airway (intubation, tracheostomy) if impending failure

Stridor requires urgent evaluation by ENT/anesthesia/emergency team.