Obstructive Airway Disorders

• Are diseases that cause obstruction at various parts of the respiratory tract
• Divided based on an imaginary line through the thoracic inlet.
• There are 2 main groups:

• Extrathoracic / Upper Airway Obstruction – affects mainly the inspiratory phase of respiration. Main feature is stridor.
• Intrathoracic / Lower Airway Obstruction – affects mainly expiratory phase. Main feature is wheeze.

Congenital

• Laryngomalacia
• Laryngeal web
• Laryngeal stenosis
• Laryngocele
• Tracheomalacia
• TOF (Tracheo-esophageal fistula)
• Vocal cord paralysis
• Craniofacial anomalies
• Vascular rings
• Double aortic arch

Acquired

• Infections: epiglottitis, LTB (Laryngotracheobronchitis), retropharyngeal abscess, peritonsillar abscess, bacterial tracheitis, diphtheria
• Burns
• Foreign body aspiration
• Trauma
• Allergy
• Neoplasms

• Bronchiolitis
• Bronchial asthma

• Also called congenital laryngeal stridor.
• Symptoms present during the first few weeks of life and increase in severity for up to 6 months although improvement can start from any age.
• There is softening of the larynx causing them to flatten on breathing.

Clinical Features

• Stridor, worsened by exertion (crying, feeding, agitation), supine position or viral infections of URTI. May have chest deformity.

Diagnosis

• Direct laryngoscopy

Treatment

Self-limiting. Symptoms usually subside by 12-18 months.

• Reassure the mother
• Advise to feed slowly
• Place in prone position

• Occurs due to the presence of a web in the anterior portion of the larynx.
• Presents at birth or within the first few weeks.

Clinical Features

• Noisy breathing; Weak harsh cry; Respiratory distress.

Diagnosis

• Direct laryngoscopy

Treatment

• Excision of web followed by repeated dilation using a laryngeal dilator
• Lysis of web with a CO2 laser

A. Supraglottic Causes:

• Epiglottis
• Retro-Pharyngeal Abscess
• Retro-Tonsillar Abscess
• Peri-Tonsillar Abscess

B. Subglottic Causes

Croup – Viral

• Membranous
• Spasmodic

Bacterial – Tracheitis

• Age: 3 months – 5 years for subglottic lesions, 3 – 7 years for supraglottic lesions
• Sex: Male predilection
• Climate: Common in cold weather
• Aetiologic Agent: Viral – Subglottic, Bacterial – Supraglottic
• Endogenous Factor: Atopy
• Anatomic Defect

URTI INFLAMMATION → EDEMA → LARYNGEAL SPASM → AIRWAY OBSTRUCTION

Supraglottic

• Bacteria – H. Influenza

Subglottic

• Viral
• Parainfluenza virus (75%)
• Adenovirus
• RSV (Respiratory Syncytial Virus)
• Measles virus

Other Agents

• Strept Pyogenes
• Strept Pneumoniae
• Staph Aureus
• Atopy

Supraglottic

• Fever and Toxicity
• Quiet and wet sound (Stridor)
• Muffled voice
• Drooling of Saliva
• Dysphagia
• Trismus
• Posturing

Subglottic

• Preceding URTI
• Cough – Barky
• Stridor
• Hoarse voice
• Fever
• Sign of respiratory distress
• Restlessness
• Respiratory failure
• Cardio-pulmonary arrest

• X-ray - Posterior - anterior view; Lateral Cervical view

This can help visualize any structural abnormalities in the airways or surrounding structures that might be causing the obstruction.

• FBC (Full Blood Count)

Elevated white blood cell count might indicate an ongoing infection contributing to airway inflammation and obstruction.

• ESR (Erythrocyte Sedimentation Rate)

An elevated ESR could indicate the presence of inflammation, which is common in obstructive airway diseases.

• Pulse Oximetry

Measuring oxygen saturation in the blood can help assess the severity of airway obstruction and its impact on oxygen exchange.

• Blood gases

Measuring blood gases, including oxygen and carbon dioxide levels, provides important information about respiratory function and potential respiratory failure.

A. Severe Presentation

• Medical Emergency
• Multi-disciplinary Approach

Airway Stabilization

• Nasotracheal intubation
• Tracheostomy

Precautions

• Avoid throat examination
• Avoid changing position
• Avoid agitating child

Medical Interventions

• Administer oxygen
• Commence IV fluids
• Post extubation care

B. Conservative Treatment

• Nebulize adrenaline
• Racemic adrenaline
• Dexamethasone
• Steam inhalation
• Humidity
• Antibiotic
• Ipecac/Inducing vomiting

• Most common cause of acute upper respiratory tract obstruction
• Refers to inflammatory obstruction of larynx, trachea, bronchi
• Triad of stridor, hoarseness, barky cough
• Best considered a syndrome of 3 major entities:
• Viral croup
• Severe bacterial tracheitis
• Spasmodic croup
• Croup = acute laryngotracheobronchitis

Comparison of Major Entities

Aetiology

• Viral – Parainfluenza 1, 2, and 3 may be causative, RSV, Influenza A & B, Rhino virus, ECHO, Coxsachie, Measles
• Bacterial – Staph. aureus, Moraxella catarrhalis, nontypable H. influenza

Epidemiology

• Common during both rainy and dry seasons, with the highest incidence occurring at the peak
• Highest during the winter months
• Age 3 months – 3 years. Peak in the 2nd year of life

Clinical Features

• Watery nasal discharge 1 – 3 days prior to onset of symptoms
• Classically, barky cough, hoarseness, stridor
• Temperature usually 38.5°C but may reach 39-40°C
• Symptoms worse at night
• Positive history of contact with persons with features of URTI
• Usually no postural preference
• Examination reveals:
• Restlessness, fever, cyanosis, obtundation
• Auscultation - reduced breath sounds and rhonchi

Investigations

• Neck x-ray AP view – subglottic narrowing giving a pencil tip appearance, also called ‘steeple sign’
• Pulse oximetry
• FBC (Full Blood Count)

Treatment

Treatment depends on croup score

<5: Mild

• Extra fluids and antipyretics at home
• Educate on signs to look out for that would indicate worsening condition

5 - 8: Moderate

• Mist therapy in the emergency room or at home depending on age
• Corticosteroids - dexamethasone 0.6-1mg/kg

Severe: >8

• Humidified oxygen - soothes the throat, liquefies secretions, relieves hypoxia
• Corticosteroids - IM dexamethasone
• Nebulised adrenaline (racemic or L-form)
• 0.25-0.75ml of 2.25% solution in 3ml of normal saline given every 20mins via intermittent positive pressure breathing
• If no response, intubate

Inflammatory swelling of the epiglottis, aryepiglottic folds, ventricular bands, and arytenoids.

Spares vocal cords. Presents with an acute fulminating course of fever, sore throat, dyspnea, and rapidly progressing respiratory obstruction.

Etiology

H.influenzae type b

Clinical Features

• Age 2-6 years
• High fever; Difficulty swallowing; Drooling of saliva; Dyspnea; Rapidly progressing respiratory obstruction (usually over a few hours); Tripod position
• Usually no cough
• Child is too ill to speak
• Cyanosis; Coma
• Stridor is a late finding-near complete airway obstruction

Investigation

• Direct laryngoscopy under anesthesia - cherry red swollen epiglottis
• Lateral Neck X-ray – thumbprint appearance
• FBC (Full Blood Count) – polymorphonuclear leukocytosis
• ESR (Erythrocyte Sedimentation Rate) – raised
• Blood culture
• Pulse oximetry

Treatment

• Maintain airway - preferably intubate
• Disturb child as little as possible
• Humidified oxygen
• Chloramphenicol
• Ceftriaxone
• Cefotaxime

Nodes drain portions of oropharynx, nasopharynx, posterior nasal passages, and alimentary mucosa. The space is obliterated by the 3rd-4th year of life.

Aetiology

• Complication of bacterial pharyngitis
• Extension of vertebral osteomyelitis
• Penetrating injury to posterior pharynx
• Grp. A beta-hemolytic Streptococcus
• Oral anaerobes
• Staph. aureus
• Klebsiella spp.; H.influenzae; Atypical mycobacteria

Clinical Manifestations

• Fever; Irritability; Reduced oral intake; Pain while swallowing; Drooling; Neck stiffness; Torticollis; Opisthotonus; Refusal to move neck; Muffled voice; Stridor; Respiratory distress; Cervical lymphadenopathy; High-grade fever.

Investigations

• Lateral neck X-ray - widening of the retropharyngeal space, air-fluid level
• CT scan
• FBC (Full Blood Count) ESR

Treatment

• Medical
  • Maintain airway, disturb as little as possible
  • Antibiotics
• Surgical
  • I & D (Incision and Drainage)

Complications

• Mass effect - causing airway compression, septicemia – aspiration, rupture of the abscess
• Mediastinitis, purulent pericarditis and tamponade, pyopneumothorax, pleuritis, empyema, or bronchial erosion - 40-50% mortality rate

Abscess involves the tonsil capsule and adjacent lateral wall (superior constrictor).

Occurs post-tonsillitis and is typically unilateral. Common in school-aged children.

Group A beta-hemolytic streptococci are most prevalent, along with Staphylococci, Pneumococci, and Haemophilus organisms.

Features

• Throat pain
• Fever, Malaise
• Trismus
• Otalgia
• Odynophagia, dysphagia
• Salivation and Drooling
• Thickened speech "hot potato–sounding" voice occurs
• Fetor oris
• Cervical adenitis
• Hyperemia and edema of uvula, tonsils, and palate
• Deviation of uvula to the opposite side

Treatment

• Conservative – antibiotics, analgesics, oral gargle.
• Needle aspiration – diagnostic and therapeutic - cooperative child under Local anesthesia on chair
• Intra-oral approach – incision and drainage through point of maximum bulge