AETIOPATHOGENESIS OF UPPER AIRWAY OBSTRUCTION IN CHILDREN_111841.pptx

AETIOPATHOGENESIS OF UPPER AIRWAY OBSTRUCTION IN CHILDREN

1. AETIOPATHOGENESIS OF UPPER AIRWAY OBSTRUCTION IN CHILDREN BY DR. UMAR AMINU REGSITRAR DEPT. OF ENT/H&N SURGERY ATBUTH, BAUCHI 26 TH SEPT. 2025

2. OUTLINES Introduction Relevant anatomic considerations Classifications Aetiopathogenesis Differential diagnosis Diagnostic approach Conclusion References

3. INTRODUCTION Paediatric airway problems are different from adult problems because congenital abnormalities manifest themselves early in life and the airway is significantly narrower Airway obstruction is the reduction in caliber of airway located above the carina, severe enough to cause functional disability which can be in form of complete or partial obstruction in children, can be at the level of the nasal or pharyngeal airway causing a low-pitched snoring-like noise—‘ stertor ’

4. Laryngotracheal obstruction is more likely to cause a ‘higher-pitched stridor ’ although there is some overlap. It is likely to occur at the sites of anatomic narrowing, e.g cricoid ring. It is one of the most life threatening emergencies in the world Early diagnosis and management is essential.

5. CLASSIFICATION OF UPPER AIRWAY OBSTRUCTION According to site/location; Oropharyngeal Nasopharyngeal Laryngeal Supraglottic Glottic Infraglottic /subglottic (to the level of the carina) According to nature Complete Partial According to duration; Acute Chronic

6. PECULIARITIES OF PAEDIATRIC UPPER AIRWAY Larger tongue in comparison to size of mouth Delicate teeth and gums Floppy epiglottis Laryngeal cartilages are soft and collapse easily Infant larynx is high up in the neck level of glottis being opposite to c3 and c4 at rest and between C1 and C2 during swallowing (more superior and funnel shaped) Thyroid cartilage in an infant is flat Infant larynx is small and conical Submucosal tissues of the larynx is comparatively loose and easily gets oedematous with trauma and inflammation leading to obstruction

7. AETIOPATHOGENESIS Nasopharynx ; The newborn is a near-obligate nasal breather and nasal obstruction will therefore produce difficulty in breathing. Larynx and trachea ; The narrowest point in the baby’s airway is the cricoid ring. Poiseuille’s law dictates that the fourth power of the radius affects airway resistance, so a small reduction in airway radius can produce a profound increase in resistance in an already very small lumen (2-mm radius in a newborn).

8. As air passes through a narrow point, the pressure at the point of narrowing reduces ( Bernoulli’s principle ). As air passes through an already narrowed tube, the tube tends to narrow further ( Venturi’s effect ). This reduced pressure plus increased flow rate causes vibration in the walls of the ‘tube’, Streamlined or ‘laminar’ flow becomes disordered and ‘turbulent’. This vibration produces a sound which is recognised as ‘ stridor ’.

9. Clinical features of airway obstruction include; stridor , tachypnoea , poor feeding, sternal recession as the baby works hard to breath, and in the late stages, tiredness, exhaustion and cyanosis—a truly desperate sign. Stridor is typically inspiratory , but as obstruction progresses, it becomes biphasic. Biphasic stridor needs immediate attention.

10. ETIOLOGY Congenital anomalies Bilateral choanal atresia Laryngeal web, Laryngeal cysts Layngomalacia Tracheomalacia Subglotic stenosis . Subglottic haemangioma . Vascular ring Congenital vocal cord paralysis Acquired Infections Ludwig angina Diphtheria Acute Epiglottitis Acute Laryngo -trachea-bronchitis Recurrent respiratory papillomatosis . Tonsilitis and Adenoiditis Neoplasms Benign and malignant neoplasms of oral cavity, pharynx, larynx

11. Trauma Blunt or penetrating laryngeal injury. Iatrogenic trauma from endoscopy, especially in infants and children Fractures of the mandible or maxillofacial injuries. Foreign body in larynx Neurological; Bilateral vocal cord paralysis. Edema of the larynx Due to irritant fumes or gases, flame, chemicals Allergy ( angioneurotic or drug sensitivity) Radiation Systemic diseases

12. CONGENITAL CAUSES BILATERAL CHOANAL ATRESIA Persistence of the bucconasal membrane Unilateral/Bilateral, complete/incomplete, bony or memebranous Bilateral atresia presents with respiratory obstruction Diagnosis made with; presence of mucoid discharge in the nose, absence of air bubbles in nasal discharge, failure to pass NG tube, flexible nasal endoscopy, installing radiopaque dye, CT scan in axial plane is more useful

13. CONGENITAL CAUSES LARYNGEAL WEB Incomplete recanalization of the larynx. Mostly seen between the vocal cords and has a concave posterior margin Presents with; airway obstruction, weak cry or aphonia from birth LARYNGEAL CYST Arises in the aryepiglottic fold and appears as bluish, fluid filled smooth swelling in the supraglottic larynx Presents with; respiratory obstruction

14. CONGENITAL CAUSES LARYNGOMALACIA; This condition (floppy larynx) may appear within an hour or two of birth, but more often becomes noticeable in the first few weeks. Most common congenital anomaly of the larynx It is characterised by an intermittent stridor of varying severity due to an indrawing of floppy supraglottic structures (particularly the arytenoids and aryepiglottic folds) during inspiration

15. which increases with cry and decreases on putting the child in prone position, and sometimes associated with cyanosis. Endoscopic features include a tightly curled ‘omega’- shaped epiglottis, bulky tethered aryepiglottic folds and redundant arytenoid and supraglottic mucosa. In severe cases, the aryepiglottic folds can be divided to expand the laryngeal introitus ( aryepiglottoplasty or supraglottoplasty ).

16. SUBGLOTTIC STENOSIS Its due to abnormal thickening of cricoid cartilage or fibrous tissue seen below the vocal cords Child may remain asymptomatic until URTI cause dyspnea and stridor Splitting of the cricoid and upper trachea with insertion of costal cartilage into the split is the standard surgical approach.

17. CONGENITAL CAUSES CONGENITAL VOCAL CORD PARALYSIS It could be unilateral or bilateral (Unilateral more common) Birth trauma or congenital anomaly of the great vessels or the heart Bilateral paralysis may be due to Hydrocephalus or Arnold chiari malformation, intracerebral hemorrhage during birth or menigocele . Bilateral paralysis presents with bilateral abductor paralysis and respiratory obstruction

18. The diagnosis is made by laryngoscopy and it is sometimes possible to see the larynx in the awake patient with a transnasal fibreoptic endoscope. An attempt should be made to treat the condition conservatively, as most will recover within 2–3 years. In some cases the stridor is so bad and indrawing so severe that tracheostomy is the only treatment.

19. Vascular Rings Abnormal blood vessels in the chest may compress the trachea and oesophagus Classically produce an inspiratory and expiratory stridor associated with feeding difficulties. Compression on the trachea causing a pulsatile swelling obvious at endoscopy, if suspected, they are nowadays well demonstrated by magnetic resonance imaging (MRI).

20. ACQUIRED CAUSES (INFLAMMATORY) ACUTE EPIGLOTTITIS (SUPTRAGLOTTIC LARYNGITIS) Confined to the supraglottic structures; epiglottis, aryepiglottic folds and arytenoids Edema of above structures causing airway obstruction Age between 2-7 years but may affect adults Causative organism; Haemophilus influenza type B

21. ACUTE LARYNGOTRACHEOBRONCHITIS (CROUP) Viral infection ( Parainfluenza type I and II ) affecting children between 6 months to 3 years Edema of the loose areolar tissues of the subglottic region with thick tenacious secretions and crusts that may occlude the airway Clinical syndrome of hoarseness, inspiratory or biphasic stridor and barking cough Endoscopy should be avoided in the acute period (as it increases oedema ) but should be done to identify an underlying abnormality if attacks recur.

22. ACQUIRED CAUSES (INFLAMMATORY) LARYNGEAL DIPHTHERIA Faucial diphtheria affecting children below 10 years Diagnosis is clinical and confirmed by smear of Corynebacterium diphtheria Formation of a tough pseudo membrane over the larynx and leading to airway obstruction

23. ACQUIRED CAUSES (INFLAMMATORY) TONSILITIS Recurrent tonsillitis from recurrent URTI with huge tonsillar hypertrophy can cause a certain level of airway obstruction by narrowing the oropharyngeal pathway of breathing ADENOIDITIS Adenoiditis with adenoid hypertrophy causing blockage of the nasopharyngeal air column can also cause some degree of airway obstruction manifested by snoring, mouth breathing and obstructive sleep apnea

24. Juvenile-Onset Recurrent Respiratory Papillomatosis Juvenile-onset recurrent respiratory papillomatosis (JORRP) is caused by the human papilloma virus (HPV). The virus is transmitted to the baby via the mother at birth. JORRP is characterised by recurrent warty swellings in the larynx causing hoarseness and if severe, stridor and very occasionally with airway obstruction.

25. ACQUIRED CAUSES (TUMORS) Benign and malignant neoplasms of the tongue, pharynx, larynx and thyroid The cause is dependent on a number of factors as age, gender, occupation, exposure to chemicals or ionizing radiation, smoking and alcohol intake

26. ACQUIRED CAUSES (TRAUMATIC) LARYNGOTRACHEAL TRAUMA Most common cause is automobile accidents when neck strikes a steering wheel, a cable or wire, blow or kick on the neck, strangulation. Penetrating injuries with sharp instruments or gunshot wounds Pathological changes seen could be; hematoma and oedema , subcutaneous emphysema, dislocation of the cricoarytenoid and the cricothyroid joints, fractures of the hyoid bone, thyroid and cricoid cartilages and upper tracheal rings

27. FRACTURE OF MANDIBLE OR MAXILLOFACIAL FRACTURES

28. ACQUIRED CAUSES (TRAUMATIC) FOREIGN BODY IN THE LARYNX Very common in children It’s usually secondary to play or fight while having something in the mouth It could be vegetable FB or non-vegetable FB (plastic whistles or toys, nails, safety pins or ball bearings) It causes either complete or partial airway obstruction in the last stage depending on the size obstructing the lumen

29. ACQUIRED CAUSES (NEUROLOGICAL) BILATERAL ABDUCTOR PARALYSIS Neuritis and surgical trauma are the most common causes and are often acute Most commonly occurs post thyroidectomy. Other causes been pressure on the nerves, stroke or other brain injury or inflammation (mainly viral infection) Its due to paralysis of the recurrent laryngeal nerve

30. EDEMA OF THE LARYNX It involves the supraglottic or subglottic region where laryngeal mucosa is loose, rarely occurs in the vocal cords due to sparse subepithelial connective tissue It occurs due to infections, trauma, allergy, neoplasms , radiation and systemic diseases (nephritis, heart failure and myxedema)

31. DIAGNOSTIC APPROACH AP/lat soft tissue neck X-ray ; shows radio-opaque FB Chest X-ray ; for tracheal deviation, FB , cardiac silhouette suggesting vascular ring Flexible nasal endoscopy ; Bedside gold standard for dynamic assessment. Direct Laryngoscopy & Bronchoscopy ; the definitive diagnosis and often therapeutic procedure for evaluating the airway from supraglottis to carina.

32. CT neck/chest with contrast ; for evaluating the masses, abscesses, and vascular abnormalities MRI ; gold standard for defining vascular rings and complex for soft tissue masses

33. CONCLUSION Upper airway obstruction is a life threatening emergency which can occur at anytime and anywhere All physicians should be proficient in all types of airway management including technique require to secure a surgical airway

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35. REFERENCES Diseases of Ear, Nose and Throat Surgery, by PL Dhingra , Shruti Dhingra . Scott-Brown's Otolaryngology, Head and Neck Surgery. 7th Edition. Key topics Otolaryngology and Head and Neck Surgery 3 rd edition