Airway Obstruction

Laryngomalacia(congenital laryngeal stridor)75% of all causes of stridor in infants.Most common congenital abnormality of the

larynx.

Weakness of the supraglottic larynx leads to prolapse of the supraglottis during inspiration, producing stridor and sometimes cyanosis.

The condition manifests at birth or soon after, and usually disappears by 2 years of age.

Stridor is increased on crying and feeding but subsides on placing the child in prone position.

Type I: inward collapse of the aryepiglottic folds

Type II: a long, tubular epiglottis which curls on itself, often occurs in association with type I laryngomalacia

Type III: anterior, medial collapse of the cuneiform and corniculate cartilages to occlude the laryngeal inlet during inspiration

Type IV: posterior inspiratory displacement of the epiglottis against the posterior pharyngeal wall or inferior collapse to the vocal folds

Type V: short aryepiglottic folds

Classification of laryngomalacia:

Type I: prolapse of mucosa overlying the arytenoid cartilages

Type II: foreshortened aryepiglottic foldsType III: posterior displacement of the

epiglottis

Alternative classification of laryngomalacia ( Olney et. al, 1999)

Direct laryngoscopy showed elongated epiglottis, curled upon itself (omega-shaped Ω), floppy aryepiglottic folds and prominent arytenoids.

Flexible laryngoscope is very useful to make the diagnosis.

Mostly, treatment is conservative. An endoscopic aryepiglottoplasty may be

required to release the epiglottis and reduce the aryepiglottic fold.

Tracheostomy may be required for some cases of severe respiratory obstruction

Omega-shaped epiglottis in laryngomalacia

Congenital / Acquired

Congenital It is due to abnormal thickening of cricoid cartilage or

fibrous tissue seen below the vocal cords. Child may remain asymptomatic till upper respiratory

infection causes dyspnoea and stridor. Cry is normal.

Diagnosis is made when subglottic diameter is less than 4 mm in full-term neonate (normal 4.5-5 .5 mm) or 3 mm in premature neonate (normal 3.5 mm).

Many cases of congenital stenosis improve as the larynx grows but some may require surgery.

Subglottic stenosis:

Acquired Subglottic stenosis is seen most commonly in

premature babies who required prolonged ventilation by endotracheal tube, but may occur at any age from intubation or trauma.

Clinical features include stridor on exertion, or with respiratory infection.

Tracheostomy may be necessary to secure airway.

Treatment is highly specialized and laryngotracheoplasty may required.

Subglottic stenosis cannot always be avoided.

Endoscopic view showing moderate subglottic stenosis

The commonest cause used to be thyroid surgery, but now most causes are idiopathic.

Voice is preserved, with stridor most evident on exertion.

Flexible laryngoscopy reveals limitation of abduction of the cords on inspiration.

Management includes observation only, a choice of intralaryngeal procedures to increase the airway at the glottic level, or tracheostomy.

Bilateral vocal cord palsy:

Malignant lesions of the larynx and hypopharynx can present with stridor due to tumour obstruction of the airway or by causing vocal cord palsy and oedema.

Stridor can also occur after radiation for laryngeal cancers.

It is not always possible to secure the airway before tracheostomy.

Debulking the tumour to improve the airway while awaiting definitive management is an option.

Tumours presenting with stridor are usually well advanced locally and may need total laryngectomy for clearance

Malignancy :

Foreign bodysudden onset of stridor in formerly

normal child – regard as d/t FB until proved otherwise.

H/O choking and coughing (esp while eating) -likelihood of aspiration

Peanuts = dangerous and never give to youngsters.

Examination and CXR may be entirely normal

Only way TRO FB in bronchus bronchoscopy.

Larger FB - lodge in the larynx and cause severe respiratory distress.

It may be possible to remove it by the Heimlich manoeuvre

if fails, endoscopy or tracheostomy will be necessary.

The management of airway insufficiency always depends on the severity of the obstruction, and severe obstruction necessitates immediate airway support by oxygen, endotracheal intubation or even tracheostomy.

If time and the child’s condition allow, every child with stridor should have a PA chest X-ray and a lateral soft-tissue film of the neck, which will show the larynx and upper trachea clearly.

If a vascular ring or tracheooesophageal fistula is suspected, a barium swallow is a necessary investigation

Management outline of airway obstruction:

Neonates may be intubated without the need for general anaesthesia but great care must be taken not to damage the larynx and cause further obstruction from haematoma or oedema.

Older children, unless so anoxic as to be unconscious, will require general anaesthesia for intubation, and at the same time the larynx, trachea and bronchi should be inspected.

The diagnosis is then usually apparent and further management can be directed appropriately.

In managing paediatric airway problems, the airway is secured with a direct laryngoscopy.

If endotracheal intubation is difficult, a laryngeal mask airway or a rigid bronchoscope is used to maintain the airway and ventilate the patient while tracheostomy is performed.

If rapid deterioration occurs and there is not sufficient time for a tracheostomy, a cricothyrotomy can provide emergency oxygenation.

In adults, endotracheal intubation is usually possible

Tracheostomy

Tracheostomy is making an opening in the anterior wall of trachea and converting it into a stoma on the skin surface

Functions of Tracheostomy1) Alternative pathway for breathing2) Improves alveolar ventilation

In respiratory insufficiency by ↓the dead space and resistance to airflow

3) Protects the airwaysBy using cuffed tube, tracheobronchial tree is

protected against aspiration of pharyngeal secretions(in bulbar paralysis or coma) and blood(in haemorrhage from pharynx, larynx or maxillofacial injuries)

4) Permits removal of tracheobronchial secretionsWhen patient is unable to cough as in coma ,

head injuries, respiratory paralysis; or when cough is painful

5) Intermittent positive pressure respiration (IPPR)If IPPR is required beyond 72 hours,

tracheostomy is superior to intubation

6)To administer anaesthesiaWhen endotracheal incubation is difficult or

impossible

Indications

1. Respiratory obstruction2. Retained secretions3. Respiratory insufficiency

Respiratory obstructionInfections

Acute laryngo-tracheo -bronchitis, acute epiglottitis, diphtheria

Ludwig's angina, peritonsillar, retropharyngeal or parapharyngeal abscess, tongue abscess

TraumaExternal injury of larynx and tracheaTrauma due to endoscopies, especially in infants and

childrenFractures of mandible or maxillofacial injuries

Neoplasm

Foreign body larynxOedema larynx due to steam, irritant

fumes or gases, allergy , radiationBilateral abductor paralysisCongenital anomalies

Laryngeal web, cysts, tracheo -oesophageal fistula

Bilateral choanal atresia

Retained secretionsInability to cough

Coma e.g. head injuries, CVA, narcotic overdoseParalysis of respiratory muscles, e.g. spinal

injuries, polio, Guillain- Barre syndrome, myasthenia gravis

Spasm of respiratory muscles, tetanus, eclampsia, strychnine poisoning

Painful coughChest injuries, multiple rib fractures, pneumonia

Aspiration of pharyngeal secretionsBulbar polio, polyneuritis, bilateral laryngeal

paralysis

Respiratory insufficiencyChronic lung conditions(emphysema,

chronic bronchitis, bronchiectasis, atelectasis)

Indications ininfants and childrenInfants (mostly congenital lesions)Subglottic haemangiomaSubglottic stenosisLaryngeal cystGlottic webBilateral vocal cord paralysis

Children (mostly inflammatory or traumatic lesions)

Acute laryngo-tracheo-bronchitisEpiglottitisDiphtheriaLaryngeal oedema (chemical/thermal

injury)External laryngeal traumaProlonged intubationJuvenile laryngeal papillomatosis

Complications

ImmediateHaemorrhageApnoea

This follows opening of trachea in a patient who had prolonged respiratory obstruction. This is due to sudden washing out of CO2 which was acting as a respiratory stimulus. Treatment is to administer 5% CO2 in oxygen or assisted ventilation

Pneumothorax due to injury to apical pleuraInjury to recurrent laryngeal nervesAspiration of bloodInjury to oesophagus

Intermediate(first few hours or days)Bleeding, reactionary or secondaryDisplacement of tubeBlocking of tubeSubcutaneous emphysemaTracheitis and tracheobronchitis with

crusting in tracheaAtelectasis and lung abscessLocal wound infection and

granulations

Late(with prolonged use of tube for weeks and months)

Haemorrhage, due to erosion of major vessel Laryngeal stenosis, due to perichondritis of cricoid cartilage Tracheal stenosis, due to tracheal ulceration and infection Tracheo-oesophageal fistula, due to prolonged use of cuffed

tube or erosion of trachea by the tip of tracheostomy tube Problems of decannulation(commonly in infants and

children) Persistent tracheocutaneous fistula Problems of tracheostomy scar Corrosion of tracheostomy tube and aspiration of its

fragments into the tracheobronchial tree

ReferencesDiseases of ear, nose & throat,

DhingraLecture Notes on Diseases of the

Ear, Nose, and Throat