Overview
Definition:
Subglottic stenosis refers to a narrowing of the airway at the level of the cricoid cartilage and immediately below it, which is the narrowest part of the pediatric airway.
Epidemiology:
Congenital subglottic stenosis is the most common congenital abnormality of the pediatric airway, affecting approximately 1 in 2,000 to 1 in 10,000 live births
Acquired stenosis is more common in neonates undergoing prolonged intubation or tracheostomy.
Clinical Significance:
Subglottic stenosis is a critical condition in pediatrics due to the potential for significant airway obstruction, respiratory distress, and long-term morbidity
Prompt recognition and appropriate management are vital for preventing life-threatening events and ensuring normal development.
Clinical Presentation
Symptoms:
Inspiratory stridor, which may worsen with crying or agitation
Barking cough
Increased work of breathing
Tachypnea
Retractions (supraclavicular, intercostal)
Feeding difficulties
Recurrent croup-like symptoms unresponsive to conventional treatment
Cyanosis in severe cases.
Signs:
Audible stridor at rest
Paradoxical chest wall movement
Nasal flaring
Accessory muscle use
Hoarseness or weak cry may be present
Failed extubation with recurrent airway obstruction
Vital signs may show tachycardia and hypoxia in severe distress.
Diagnostic Criteria:
Diagnosis is typically made based on clinical presentation, characteristic stridor, and confirmed by laryngoscopy and bronchoscopy
Grading systems (e.g., Benjamin-Parkins-Siegle) are used to classify the severity based on the degree of luminal compromise.
Diagnostic Approach
History Taking:
Detailed birth history (gestational age, prematurity, birth trauma)
History of prolonged intubation or mechanical ventilation
Previous episodes of croup or airway issues
Family history of airway anomalies
Presence and characteristics of stridor
Worsening factors.
Physical Examination:
Complete airway assessment, including observation for signs of respiratory distress
Auscultation for stridor, its timing (inspiratory, expiratory, biphasic), and location
Palpation of the neck for any masses or tenderness
Assess feeding and swallowing
Thorough neurological examination.
Investigations:
Flexible laryngoscopy/bronchoscopy is the gold standard for diagnosis and grading
Chest X-ray may show subglottic narrowing or signs of associated anomalies
CT scan or MRI can provide detailed anatomical information but are usually not the primary diagnostic tools for stenosis itself
Laryngoscopy can show edema, granulation tissue, or intrinsic narrowing.
Differential Diagnosis:
Laryngomalacia
Tracheomalacia
Vocal cord paralysis
Foreign body aspiration
Bacterial tracheitis
Papillomatosis
Vascular rings or slings
Goiter
Extrinsic compression of the airway.
Management
Initial Management:
Airway stabilization is paramount
Oxygen supplementation
Minimal handling to avoid airway compromise
Sedation should be used cautiously as it can worsen airway obstruction
Early consultation with ENT and anesthesia teams
Secure airway if necessary via intubation or tracheostomy.
Medical Management:
Primarily supportive
Antibiotics for secondary infection
Steroids are sometimes used to reduce edema, though their efficacy for established stenosis is debated and typically not a primary treatment
Acid suppression therapy if reflux is contributing to inflammation.
Surgical Management:
Indications include symptomatic severe stenosis (Grade III-IV), failure of conservative management, or airway instability
Options include: balloon dilation, endoscopic laser or cold steel resection of stenotic segment, laryngotracheal reconstruction (e.g., anterior or posterior graft, slide tracheoplasty), and tracheostomy with or without stenting.
Supportive Care:
Close monitoring of respiratory status
Humidified air
Adequate hydration and nutrition
Management of gastroesophageal reflux if present
Speech and feeding therapy
Psychological support for child and family.
Ent Referral
Indications For Referral:
Persistent or worsening stridor, especially if inspiratory
Respiratory distress not improving with conservative measures
Suspected congenital airway anomaly
History of prolonged intubation with extubation failure
Recurrent episodes of croup-like illness
Cyanosis or feeding difficulties associated with stridor.
Urgent Referral Criteria:
Any child presenting with significant respiratory distress, stridor at rest, retractions, tachypnea, or signs of hypoxia requires immediate ENT assessment
Infants with stridor who fail extubation should be referred urgently.
Information To Provide:
Detailed history of stridor onset, nature, and progression
Associated symptoms (cough, feeding issues, apnea)
Birth history
Intubation history (duration, size)
Previous medical interventions or diagnoses
Current medications
Vital signs and respiratory status
Any prior investigations or treatments.
Complications
Early Complications:
Airway instability and obstruction
Laryngeal trauma during procedures
Bleeding
Infection
Pneumonia
Vocal cord injury.
Late Complications:
Persistent stridor or dyspnea
Voice abnormalities
Tracheostomy dependence
Failure to thrive
Pulmonary hypertension
Psychological impact
Scarring and restenosis.
Prevention Strategies:
Minimize duration of intubation in neonates
Use appropriately sized ETTs
Careful extubation attempts with adequate airway preparation
Early identification and management of risk factors like GERD
Gentle handling of the pediatric airway.
Prognosis
Factors Affecting Prognosis:
Severity and length of stenosis
Cause of stenosis (congenital vs
acquired)
Extent of airway involvement
Age of child at diagnosis and intervention
Presence of comorbidities
Success of surgical intervention.
Outcomes:
Prognosis varies widely
Mild cases may resolve spontaneously or with conservative management
Severe cases requiring surgery can have good outcomes with appropriate reconstruction, but long-term follow-up is essential
Some children may require ongoing tracheostomy or multiple revisions.
Follow Up:
Regular follow-up with ENT specialists is crucial
Serial laryngoscopies/bronchoscopies to monitor airway healing and identify restenosis
Speech and feeding assessment
Pulmonary function tests may be considered in older children
Management of associated conditions like GERD.
Key Points
Exam Focus:
Stridor is a key indicator of upper airway obstruction
Subglottic stenosis is the most common congenital airway anomaly
Differentiate inspiratory stridor from biphasic
Benjamin-Parkins-Siegle grading is crucial
Endoscopic airway evaluation is diagnostic gold standard
Surgical reconstruction options vary by severity.
Clinical Pearls:
Always consider subglottic stenosis in infants with persistent croup-like symptoms or failed extubation
The subglottis is the narrowest part of the pediatric airway, making it vulnerable
A trial of steroids for stridor is common but rarely resolves established stenosis
Tracheostomy is a temporizing or definitive measure for severe obstruction
Prioritize airway over definitive diagnosis in acute distress.
Common Mistakes:
Attributing persistent stridor solely to laryngomalacia without further investigation
Delaying ENT referral in symptomatic neonates or infants
Aggressive intubation or extubation in potentially stenotic airways
Underestimating the severity of airway compromise in a crying infant
Relying solely on imaging without endoscopic confirmation.