«tasdiqlayman» Tabiiy fanlar fakulteti dekani K. Asqarov

Inflammation and infection[edit]
Inflammation of the trachea is known as tracheitis, usually due to an infection. It is usually caused by viral infections,^[8] with bacterial infections occurring almost entirely in children.^[9] Most commonly, infections occur with inflammation of other parts of the respiratory tract, such as the larynx and bronchi, known as croup,^[9][8] however bacterial infections may also affect the trachea alone, although they are often associated with a recent viral infection.^[8] Viruses that cause croup are generally the parainfluenza viruses 1–3, with influenza viruses A and B also causing croup, but usually causing more serious infections; bacteria may also cause croup and include Staphylococcus aureus, Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis.^[8] Causes of bacterial infection of the trachea are most commonly Staphylococcus aureus and Streptococcus pneumoniae.^[10] In patients who are in hospital, additional bacteria that may cause tracheitis include Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa.^[8]
A person affected with tracheitis may start with symptoms that suggest an upper respiratory tract infection such as a cough, sore throat, or coryzal symptoms such as a runny nose. Fevers may develop and an affected child may develop difficulty breathing and sepsis.^[8][9] Swelling of the airway can cause narrowing of the airway, causing a hoarse breathing sound called stridor, or even cause complete blockage.^[9] Unfortunately, up to 80% of people affected by bacterial tracheitis require the use of mechanical ventilation, and treatment may include endoscopy for the purposes of acquiring microbiological specimens for culture and sensitivity, as well as removal of any dead tissue associated with the infection. Treatment in such situations usually includes antibiotics.^[9]
A trachea may be narrowed or compressed, usually a result of enlarged nearby lymph nodes; cancers of the trachea or nearby structures; large thyroid goitres; or rarely as a result of other processes such as unusually swollen blood vessels.^[11] Scarring from tracheobronchial injury or intubation; or inflammation associated with granulomatosis with polyangiitis may also cause a narrowing of the trachea (tracheal stenosis).^[11] Obstruction invariably causes a harsh breathing sound known as stridor.^[11] A camera inserted via the mouth down into the trachea, called bronchoscopy, may be performed to investigate the cause of an obstruction.^[11] Management of obstructions depends on the cause. Obstructions as a result of malignancy may be managed with surgery, chemotherapy or radiotherapy.^[11] A stent may be inserted over the obstruction. Benign lesions, such as narrowing resulting from scarring, are likely to be surgically excised.^[11]
One cause of narrowing is tracheomalacia, which is the tendency for the trachea to collapse when there is increased external pressure, such as when airflow is increased during breathing in or out, due to decreased compliance.^[12] It can be due to congenital causes, or due to things that develop after birth, such as compression from nearby masses or swelling, or trauma.^[12] Congenital tracheomalacia can occur by itself or in association with other abnormalities such as bronchomalacia or laryngomalacia, and abnormal connections between the trachea and the oesophagus, amongst others.^[12] Congenital tracheomalacia often improves without specific intervention; when required, interventions may include beta agonists and muscarinic agonists, which enhance the tone of the smooth muscle surrounding the trachea; positive pressure ventilation, or surgery, which may include the placement of a stent, or the removal of the affected part of the trachea.^[12] In dogs, particularly miniature dogs and toy dogs, tracheomalacia, as well as bronchomalacia,^[13] can lead to tracheal collapse, which often presents with a honking goose-like cough.^[14]