Expiratory Stridor - Noisy Breathing

Introduction:

Stridor is an abnormal, harsh, high-pitched breath sound created by turbulent airflow through a partially blocked airway at the level of the supraglottis, glottis, and subglottis, or trachea. It is usually associated with dyspnea or severe breathlessness and indicates an emergency requiring immediate medical attention.

Stridor can often be confused with the word stertor. Both refer to a noisy breathing sound, whereas stridor refers to a high-pitched sound at the level of the larynx or below. In contrast, stertor refers to a heavy snoring inspiratory sound that usually occurs in a coma or deep sleep and sometimes may occur due to obstruction of the upper airways.

What Are the Causes of Stridor?

There are various causes of stridor. The most common ones are listed below:

Epiglottitis: It is an acute, progressive inflammation of the oropharynx with inflammation of the epiglottis or epiglottitis, arytenoid, and aryepiglottic fold. It is common in children between two to seven years of age. It is an emergency condition as the time interval from the start of symptoms to total respiratory obstruction may be extremely short.

Causes:

• Haemophilus influenzae type B.

• Streptococcus pneumonia.

• Group A streptococci.

• Burn or Trauma.

Symptoms:

• Stridor.

• Dyspnea.

• Fever.

• Odynophagia or dysphagia.

• Severe sore throat.

• Drooling.

• Tripod position.

• Muffle voice.

Investigations:

• Blood culture.

• X-ray: Lateral view will show a large swollen epiglottis (thumb sign).

Treatment:

• Administer intravenous antibiotics.

• Steroid.

• Hydration with parenteral fluid.

• Intubation.

Laryngotracheobronchitis: Acute laryngotracheobronchitis is an acute infection involving the trachea, larynx, and bronchus. It is commonly seen in children up to 7 years. Parainfluenza viruses of three types - 1, 2, and 3 are responsible for most cases. It typically occurs during early spring and winter.

The inhaled virus goes through the nose and the nasopharynx. As a result, the body's defense mechanism, in turn, causes respiratory epithelium to become inflamed and edematous and thereby causes the narrowing of the airway. As a result, airflow through the airway becomes turbulent, and hence, a stridor is produced.

Clinical Features:

• Rhinorrhea.

• Sore throat.

• Fever.

• Cough.

• Hoarseness of voice.

• Stridor.

• Chest retraction.

Treatment: Airway management is the most important goal in treating a group. Other methods are mist therapy, corticosteroids, and racemic epinephrine.

Retropharyngeal Abscess:

The accumulation of pus at the retropharyngeal space is secondary to an infection. There are various ways in which an abscess can occur:

• Supuration of retropharyngeal lymph nodes of rouviere.

• Spread of infection from the parapharyngeal abscess.

• Trauma that may perforate the posterior pharyngeal wall leads to an infection.

• Tuberculosis of the cervical spine.

Clinical Features:

• Breathing difficulty.

• Dysphagia.

• Drooling.

• High fever.

• Stridor.

• Intercostal retraction.

• Severe sore throat.

• Difficulty in turning the head.

Treatment:

Administer intravenous broad-spectrum antibiotics and drainage by an incision in the posterior pharyngeal wall through the oral cavity. Adults with tuberculous abscesses are treated with anti-tuberculous drugs and drainage through an external neck incision when required.

Foreign Body Inhalation: The foreign body can be anything, but the most common is food. It is a common cause of acute stridor. It is most commonly seen between one and two years of age because children habitually put small objects into their mouths.

Clinical Features:

• Cough.

• Stridor.

• Dyspnea.

• Rarely aphonia.

• Sudden onset of choking in the early stage and productive cough and fever in the later stage.

• Unilateral wheezing.

• Poor chest movement.

• Reduced breath sound.

Organic foreign bodies may produce a severe mucosal reaction, while non-organic foreign bodies like coins and toys produce little or no mucosal reaction.

Treatment:

The management depends on the location of the foreign body. It can be removed easily by an experienced surgeon along with an anesthetist. Laryngoscopy or bronchoscopy can be done under local anesthesia, whereas a rigid direct laryngoscopy or bronchoscopy is usually performed under general anesthesia using a small endotracheal tube.

The patient is laid in a supine position with the neck flexed on an extended head. If the foreign body is impacted deeper, a Heimlich Maneuver in which pressure is exerted by rapid squeezing motion is applied against the xiphoid region of the sternum or by an open thoracotomy.

Laryngomalacia: It is a congenital condition mostly seen in young babies. It's a condition in which excessive softening of the laryngeal framework causes indrawing of aryepiglottic folds leading to stridor. It is seen between nine to twelve months of age.

What Are the Types of Stridor?

The types of stridor are:

• Inspiratory Stridor: It suggests an airway obstruction at or above the level of the vocal cord.

• Expiratory Stridor: It suggests airway obstruction at the level of the trachea and bronchioles. It is commonly referred to as wheeze.

• Biphasic Stridor: It suggests a supraglottic or glottic airway obstruction.

How Is Stridor Diagnosed?

The various diagnostic tests to be carried out are:

• X-ray and computed tomography (CT) scans reveal the object's location and may identify localized air trapping. In addition, CT scanning and virtual bronchoscopic imaging may provide useful information before an attempt at bronchoscopy.

• Laryngoscopy is a test in which a flexible tube is passed through the nose to look directly into the trachea.

• Magnetic resonance imaging (MRI) is an imaging test to view soft tissues. It is rarely done and helps diagnose a vascular ring's presence. A vascular ring is a congenital disability in which a large blood vessel, such as the arch of the aorta, may encircle the trachea and the esophagus and may squeeze them.

• Bronchoscopy: It is a fine, thin tube-like instrument with a camera inserted into the trachea and the larger airways to view abnormal areas inside.

• Spirometry is a simple, non-invasive method to assess lung function and detect early disease progression changes.

• Sputum Culture: The sample is sent for culture to look for any infection.

Conclusion:

Stridor usually implies a severe airway obstruction that needs emergency management. It is a multi-disciplinary condition and requires good communication among professionals to achieve successful long-term outcomes.