Stridor (peds)

This page is for pediatric patients. For adult patients, see: stridor

Background

Cross section of a trachea and esophagus anatomy.

Tracheal anatomy.

• Stridor refers to harsh upper airway sounds caused by turbulent airflow through a narrowed airway
• Classically inspiratory, indicating extrathoracic obstruction
• Pediatric airways are particularly vulnerable due to anatomical differences:
  • Smaller absolute airway diameter — 1mm of circumferential edema reduces cross-sectional area by ~60% in an infant vs. ~20% in an adult
  • More compliant airway cartilage
  • Relatively larger tongue and occiput
• Croup is the most common cause of acute stridor in children ages 6 months to 6 years
• A minimal amount of edema or inflammation can result in significant obstruction and rapid decompensation

Clinical Features

Phase of Respiration

• Inspiratory stridor: extrathoracic obstruction (supraglottic/glottic)
  • Pressure_trach < Pressure_atm
  • Croup, epiglottitis, foreign body, anaphylaxis, laryngomalacia
• Expiratory stridor (vs. wheezing): intrathoracic obstruction
  • Pressure_trach < Pressure_pleura
  • Asthma, bronchiolitis, foreign body, vascular ring
• Biphasic stridor: fixed obstruction (subglottic stenosis, hemangioma, foreign body lodged at glottis)

By Age

• Neonates: laryngomalacia (most common cause of chronic stridor in infants), subglottic stenosis, vocal cord paralysis, congenital hemangioma, vascular ring
• Infants (6 months - 2 years): croup, foreign body, laryngomalacia, subglottic hemangioma
• Toddlers/Preschool (2-6 years): croup (most common), foreign body, epiglottitis, bacterial tracheitis
• School-age and older: epiglottitis, peritonsillar abscess, retropharyngeal abscess, foreign body

Red Flags (Impending Respiratory Failure)

• Drooling, inability to swallow
• Tripod positioning, refusal to lie down
• Toxic appearance, high fever (epiglottitis, bacterial tracheitis, retropharyngeal abscess)
• Cyanosis, altered mental status, decreasing stridor with worsening respiratory distress (exhaustion)
• No cough + drooling + high fever = think epiglottitis (do NOT examine throat or agitate child)
• Sudden onset without prodrome = think foreign body aspiration

Differential Diagnosis

Pediatric stridor

<6 Months Old

• Laryngotracheomalacia
  • Accounts for 60%
  • Usually exacerbated by viral URI
  • Diagnosed with flexible fiberoptic laryngoscopy
• Vocal cord paralysis
  • Stridor associated with feeding problems, hoarse voice, weak and/or changing cry
  • May have cyanosis or apnea if bilateral (less common)
• Subglottic stenosis
  • Congenital vs secondary to prolonged intubation in premies
• Airway hemangioma
  • Usually regresses by age 5
  • Associated with skin hemangiomas in beard distribution
• Vascular ring/sling

>6 Months Old

• Croup
  • viral laryngotracheobronchitis
  • 6 mo - 3 yr, peaks at 2 yrs
  • Most severe on 3rd-4th day of illness
  • Steeple sign not reliable- diagnose clinically
• Epiglottitis
  • H flu type B
    • Have higher suspicion in unvaccinated children
  • Rapid onset sore throat, fever, drooling
  • Difficult airway- call anesthesia/ ENT early
• Bacterial tracheitis
  • Rare but causes life-threatening obstruction
  • Symptoms of croup + toxic-appearing = bacterial tracheitis
• Foreign body (sudden onset)
  • Marked variation in quality or pattern of stridor
• Retropharyngeal abscess
  • Fever, neck pain, dysphagia, muffled voice, drooling, neck stiffness/torticollis/extension

Evaluation

Immediate

• Assess airway stability — allow child to remain in position of comfort (parent's lap)
• Do NOT agitate the child if epiglottitis is suspected
• Pulse oximetry (may be normal until late)
• Observe work of breathing, air entry, level of consciousness

Stable Patient

• AP and lateral neck X-rays:
  • Steeple sign (subglottic narrowing) = croup
  • Thumbprint sign (swollen epiglottis) = epiglottitis
  • Prevertebral soft tissue widening = retropharyngeal abscess
  • Radiopaque foreign body
• CT neck with contrast if deep space infection, abscess, or mass suspected
• Direct visualization (nasopharyngoscopy / fiberoptic laryngoscopy) if available and safe

Unstable Patient

• Defer imaging — proceed directly to airway management
• Prepare for difficult airway — have smaller ETT sizes available, call for backup (anesthesia, ENT)
• See Intubation (peds) and Difficult Airway Algorithm

Laboratory

• Not routinely helpful in acute setting
• CBC, blood cultures if bacterial cause suspected (bacterial tracheitis, epiglottitis)
• Avoid phlebotomy in a distressed child with epiglottitis (agitation worsens obstruction)

Management

Croup (Most Common)

• Dexamethasone 0.6 mg/kg PO/IM (single dose, max 10mg) — cornerstone of treatment, effective even in mild croup
• Racemic epinephrine (2.25%) 0.5 mL nebulized in 3 mL NS for moderate-severe croup
  • Or L-epinephrine (1:1000) 0.5 mL/kg nebulized (max 5 mL)
  • Observe for 2-3 hours after racemic epinephrine (rebound possible)
• Humidified air/mist therapy: no proven benefit but commonly used
• Heliox for severe croup not responding to above

Epiglottitis

• Keep child calm, in parent's lap, in position of comfort
• Do NOT examine throat, do NOT lay child down, do NOT insert tongue depressor
• Call anesthesia and ENT immediately
• Controlled intubation in the operating room (preferred)
• If impending arrest: attempt intubation with experienced provider, prepare for surgical airway
• IV antibiotics after airway secured: ceftriaxone + vancomycin

Bacterial Tracheitis

• Intubation often required (thick tracheal secretions)
• IV antibiotics: ceftriaxone + vancomycin (or nafcillin)
• Frequent suctioning

Foreign Body

• If complete obstruction: BLS choking algorithm (back blows for infants, Heimlich for older children)
• If partial obstruction with stable airway: bronchoscopy for removal (do not attempt blind finger sweep)
• If unstable: attempt direct laryngoscopy for removal

Retropharyngeal/Peritonsillar Abscess

• IV antibiotics (ampicillin-sulbactam or clindamycin)
• ENT consultation for surgical drainage
• See Retropharyngeal abscess, Peritonsillar abscess

Anaphylaxis

• IM epinephrine (0.01 mg/kg, max 0.3-0.5 mg)
• See Anaphylaxis

Disposition

Admit / PICU

• Epiglottitis (PICU with secured airway)
• Bacterial tracheitis
• Severe croup not responding to treatment
• Required >1 dose of racemic epinephrine and still symptomatic
• Deep space neck infections
• Foreign body requiring bronchoscopy
• Respiratory failure or impending failure

Discharge

• Mild croup responding to dexamethasone with no stridor at rest after 2-3 hours observation
• Single dose of racemic epinephrine with resolution of symptoms after 2-3 hour observation period
• Reliable caregivers with access to return to ED
• Return precautions: worsening stridor, drooling, difficulty breathing, color change, inability to drink fluids, fever

See Also

• Stridor
• Croup
• Epiglottitis
• Intubation (peds)
• Difficult Airway Algorithm