Diseases of the trachea and bronchi: causes, symptoms, diagnosis, treatment
Diseases of the trachea and bronchi, depending on their type, may be in the competence of the family doctor, general therapist, pulmonologist, allergist, endoscopist, thoracic surgeon and even a geneticist. These diseases are not directly related to the otorhinolaryngologist, nevertheless, there are cases when patients with complaints complain of it, which can be caused by defeat of both the larynx and the trachea. In these cases, the ENT specialist should have basic information about the diseases of the trachea and bronchi, be able to differentiate the basic nosologic forms in relation to diseases of both the larynx and the trachea and bronchi, provide first aid in these diseases and refer the patient to the appropriate specialist for consultation. The basic information about diseases of the trachea and bronchi includes signs of a violation of the basic functions of the lower respiratory tract, which include the violation of airway, motor and secretory functions.
The main functional impairment for various pathological conditions of the trachea and bronchi, causing the occurrence of obstructions to the air flow, is dyspnea. By this concept, modifications of the respiratory function are implied, manifested in changes in the frequency, rhythm, and depth of breathing.
Dispnoea occurs in those cases when the lower respiratory tract due to certain pathological conditions can not provide complete oxygenation of the body and the removal of carbon dioxide from it. The accumulation of carbon dioxide in the blood is controlled by the respiratory and vasomotor centers. Increase in its concentration causes an increase and deepening of respiratory movements, an increase in heart rate. These phenomena increase the rate of respiratory air passing through the alveolar system, and increase the concentration of oxygen in the blood. An important role in the regulation of respiratory function and cardiac activity is played by vascular interoceptors, in particular carotid glomeruli. All these mechanisms function quite adequately with airways free for the air stream, however, when they are obstructed, the supply of oxygen into the body and the removal of carbon dioxide from it are insufficient, and then the phenomena of asphyxia due to the hypoxia factor arise.
In clinical terms, different forms (types) of hypoxia are distinguished: hypoxic hypoxia (lack of oxygen in the inspired air (for example, ascending to altitude), respiratory hypoxia (for diseases of the lungs and respiratory tract), hemic hypoxia (in blood diseases, in particular, in anemia, blood loss and some poisoning, for example, with carbon monoxide poisoning, nitrates, circulatory hypoxia (in case of circulatory disorders), tissue or cell hypoxia (in case of tissue respiration, for example, cyanide poisoning, When some metabolic diseases. Most hypoxia is mixed.
Hypoxic hypoxia occurs when the hemoglobin molecule is not sufficiently oxygenated, which can be due to various causes and most often pathological states of the external respiration system (paralysis of the respiratory center, myasthenia gravis blocking the function of the respiratory musculature, obstruction of the respiratory tract by internal and external tumor and edematous inflammatory processes, trauma, etc.). Hypoxic hypoxia may occur during anesthesia, exudative pleurisy, emphysema of the mediastinum and pneumothorax, or with a decrease in the respiratory surface of the alveoli (pneumonia, atelectasis, pneumosclerosis, emphysema of the lungs.) Often hypoxic hypoxia is combined with other types of hypoxia, which is determined by appropriate pathological changes in the central nervous system, tissues the organism, the activity of the cardiovascular system, blood loss, and so on.
Disturbance of airway function in the trachea and bronchi may be due to mechanical, inflammatory traumatic and neurogenic factors.
Mechanical or obstructive factors can be caused by foreign bodies of the trachea and bronchi, internal volumetric processes (infectious granulomas, tumors), external volumetric processes (tumors, emphysema, mediastinal reflux), etc. Complete stenosis of the trachea, primary and primary bronchi arises extremely rarely, but often there is a complete stenosis of the smaller bronchi, as a result of which within a few hours the air from the corresponding lobe of the lung dissolves and is replaced by a transudate, after resorption of which atelectasis occurs on that part of the lung.
Incomplete stenosis of the bronchus can occur if there is or is no valve mechanism, and the existing valve "works" only in one direction: it lets in air, or only during inspiration, or only during exhalation. If the valve prevents the entry of air into the underlying bronchi (inspiratory valve), then the resorption of air in them leads to atelectasis of the corresponding part of the lung; an expiratory valve causes an overflow of the underlying bronchi and lung tissue with air (emphysema). Valve mechanism can be caused by mobile tumors, their fragments, mobile foreign bodies, etc. With the expiratory valve, due to overflow of the lung tissue with air, it may break with the formation of air bags. With an incomplete valve mechanism, the phenomenon of hypoventilation is observed, which can occur in an inspiratory or expiratory type and is accompanied by a collapse of the lung tissue or its emphysema, respectively.
Stenosis of the trachea is similar in clinical manifestations to stenosis of the larynx, with the exception that in the stenosis of the larynx, pronounced aphonia is also observed, while in the stenosis of the trachea, the voice remains sonorous, but weakened. Full acute stenosis of the trachea leads to immediate suffocation and death of the patient for 5-7 minutes. Incomplete stenosis determines the development of hypoxic hypoxia, the adaptation to which depends on the degree of stenosis and the rate of its development.
Obstructive factors that cause hypoxia include edematous and infiltrative processes that develop with banal and specific inflammation. This should include and obstructive phenomena caused by bronchospasm in asthmatic conditions, as well as allergic edema of the mucous membrane and submucosal layer of the tracheobronchial tree.
The traumatic factors that cause dyspnea include mechanical, chemical and thermal agents, causing damage to the mucosa and submucosal layer of the trachea and bronchi of different severity (both in prevalence and in depth). Mechanical factors include foreign bodies of the trachea and bronchi, gunshot wounds, bruises and chest compressions, in which there are ruptures and detachments of these organs, crushing of the lung tissue, damage to the mediastinal organs and the spine. To the same factors should be attributed and iatrogenic lesions arising from tracheo-and bronchoscopy, when extracting foreign bodies, etc. The mechanism of chemical and physical lesions of the trachea and bronchi is identical to that which occurs when these factors are affected by the larynx and invariably accompanies it.
In the pathogenesis of dyspnea, neurological diseases can play an important role, in which there are those or other lesions of the peripheral nerves innervating the trachea and bronchi, or the central structures regulating the muscle tone of these organs. These disorders, related to motor nerves, cause motor disorders - vegetative nerves - trophic disorders and, above all, secretory function. The latter are reflected in quantitative and qualitative changes in the production of the mucous glands of the lower respiratory tract, and the motor function of the ciliary epithelium changes significantly, which disrupts excretion, that is, the evacuation function.
Hyper secretion is the response defense response to any inflammatory process that provides leaching of catabolites, dead leukocytes and microbial bodies, but excessive accumulation of mucus reduces the activity of the ciliary epithelium cessation function, and mucus itself begins to play a large role in the volume factor that enhances hypoxic hypoxia. In addition, the resulting greenhouse effect promotes multiplication of the microbiota and increased secondary infection. Thus, hypersecretion leads to the creation of a vicious circle that aggravates the pathological condition of this organ.
Hypoecretion occurs with atrophic processes in the mucosa and its elements (ozona, scleroma, silicosis and other occupational dystrophies of the respiratory tract). Hypoecretion is the result of the hypotrophy of the morphological elements, not only the mucous membranes of the respiratory tract, and their cartilaginous skeleton and other elements of these organs (smooth muscles, nervous and lymphadenoid apparatus).
At the heart of the impairment of excretion is the hypofunction of mucociliary clearance, the complete disappearance of which, caused by purulent-inflammatory or neoplastic processes, leads to bronchopulmonary stasis - the main cause of inflammation in the lower respiratory tract.
Tracheobronchial syndromes. Tracheobronchial syndromes are largely determined by the topographic anatomical relationship with the organs of the neck and mediastinum, which can significantly affect the state of the lumen of the trachea and bronchi in the occurrence of various diseases in these organs. Trachea, due to its anatomical position, makes excursions in both lateral and vertical directions; she is given the movements of the lungs, aorta, esophagus, spine. Such an active influence of neighboring organs on the trachea and bronchi often significantly modifies the functions of the latter and makes it difficult to differentiate between diseases of the organs of the breast. Thus, the pathological conditions observed in the upper part of the trachea can simulate or be associated with diseases of the larynx, similar to tracheal diseases in the lower parts, especially in the bifurcation region, often take on the aspect of bronchopulmonary diseases, and lesions in the middle trachea can be taken for diseases of neighboring organs, located at this level, especially the esophagus. Similar aspects of the difficulties of differential diagnosis of diseases of the tracheobronchial system fully concern bronchi. Significant help in this problem is provided by the knowledge of signs of tracheal and bronchial syndromes.
Tracheal syndromes are divided into high, middle and lower.
High tracheal syndromes are characterized by souring and perspiration in the larynx and upper trachea. The patient takes a forced position with the head tilted forward, relaxing the trachea and increasing its elasticity and compliance. This position should be distinguished from the forced position arising in dyspnea-laryngeal origin, in which the patient deviates head to back to facilitate chest breathing. In diseases of the upper part of the trachea, phonation is disturbed only when the lower laryngeal (recurrent) nerves are involved in the pathological process.
The average tracheal syndrome is characterized only by signs of tracheal injury. The most characteristic symptom is a cough due to its irritation to the sensitive nerves of the trachea. It is paroxysmal, sometimes indomitable character and can be a sign of both acute banal inflammatory diseases and specific and neoplastic processes. In trivial processes at the onset of the disease, a "dry" cough is especially painful, then with the appearance of sputum the intensity of sagging, pain and persecution decreases. Dyspnea with this syndrome occurs when the pathological process is characterized by a sign of obstruction of the trachea and a decrease in its airway function. Shortness of breath and signs of hypoxic hypoxia in these cases at the onset of the disease can manifest only with physical stress, but after these phenomena do not last for a long time due to the latent current deficiency of oxygen in the body. With the growth of the pathological process (edema, infiltration, compression of the growing esophagus by the tumor, mediastinal emphysema, etc.), dyspnea phenomena grow and become permanent even in a state of physical rest.
With anterior tracheal syndrome, dyspnea increases at night and is accompanied by noisy breathing. The patient suddenly wakes up during an attack of suffocation with an expression of fright, a cyanotic face, breathing and pulse are quickened. These nocturnal excesses often simulate asthma. Tracheal dyspnoea is accompanied by snoring, but unlike the laryngeal dyspnea, in which snoring occurs only on inspiration, with tracheal dyspnea, it occurs on inhalation and exhalation. Involvement in the process of recurrent nerves can be manifested by tonal voice disturbance, a characteristic feature of which is an involuntary transition of the usual tone to a falsetto (bitonal voice).
Direct contact of the trachea with the esophagus often causes joint damage in some pathological conditions, and then symptoms of esophageal lesions come to the fore. In this case, they speak of a tracheo-esophagal syndrome, which is characterized by signs of obstruction of the esophagus and respiratory obstruction of the trachea.
Some pathological conditions of the middle part of the trachea are accompanied by painful sensations, which differ from soreness and persecution in that they can irradiate in the ascending and descending directions, as well as into the spine. Usually such signs are characteristic for destructive processes (malignant tumors, infectious granulomas, wedged IT), and under such conditions respiratory tracheal noises are observed - from "white" to tonal wheezing.
Esophageal and tracheal fistulas cause the most painful phenomena caused by the ingress of fluid and food masses into the trachea: a sharp respiratory obstruction, an indomitable cough, especially if the foreign object reaches the carina.
Low tracheal syndromes are characterized by signs close to manifestations of bronchial lesions. In most cases, this syndrome is characterized by a sadening in the chest in the area of the xiphoid process, the appearance of a "deep" cough, especially indomitable and painful during the spread of the pathological process on the keel of the trachea.
Diagnosis of the above syndromes is supplemented by methods of X-ray and tracheobronchoscopy.
The latter is used for prolonged syndromal signs that are not characteristic of the banal inflammatory process to those accompanied by unusual pain syndrome, alarming changes in red blood, bloody or hemorrhagic sputum, etc.
Bronchial syndrome. The manifestations of this syndrome include impaired bronchial patency, the secretory function of their glandular apparatus, and sensory disorders that provoke the following symptoms.
Cough is the earliest and permanent symptom of a bronchial lesion. It is a reflex act, which plays a big role in the self-cleaning of the respiratory tract as from foreign bodies, and from endogenously formed products of various pathological processes (mucus, blood, pus, decay products of lung tissue). This reflex is caused by the irritation of the sensitive nerve endings of the vagus nerve, from where it is transmitted to the cough center located in the medulla oblongata. The cortical influences on the cough reflex are reduced to the possibility of its manifestation with moderate irritations of peripheral sensory receptors, but with an indomitable and violent cough these effects are insufficient to completely suppress the latter. Cough can be dry, moist, convulsive, bitonal, by origin - allergic, cardiac, with diseases of the pharynx, larynx, trachea and bronchi, reflex - with irritation of the endings of the vagus nerve of various (non-respiratory) organs. An example of the latter is an "ear" cough that occurs when the ear of the vagus nerve is irritated, "gastric" and "intestinal" cough. The so-called nervous cough is most often a habit that remains until the end of life.
Sputum is a pathological secret, secreted with a cough from the respiratory tract.
The amount of sputum given for a day is from 2-3 spittles (for acute bronchitis, in the initial stage of pneumonia) to 1-2 liters (with bronchiectasis, pulmonary edema, etc.).
Usually sputum is devoid of smell, but when stagnant and getting into it putrefactive bacteria, sputum becomes fetid (putrefactive bronchitis, bronchiectasis, lung gangrene, malignant tumor with decay).
Color, transparency and consistency of sputum depend on its composition or on the random impurity of food or inhaled substances (coal dust, dust particles of paint, etc.). Sputum can be watery and transparent, viscous and vitreous, cloudy, yellow-green, gray, with veins or blood clots, homogeneously colored blood, etc. Especially viscous sputum occurs in croupous pneumonia, during an attack of bronchial asthma, at the initial stage banal inflammatory processes in the airways.
Lamination of sputum is determined by its collection in sufficient quantities in a glass transparent vessel. With some diseases, accompanied by the release of a large amount of sputum (putrefactive bronchitis, bronchiectasis, gangrene of the lung, malignant tumor with decay, sometimes pulmonary tuberculosis with the presence of caverns), sputum on standing is divided into 3 layers. The top layer - opaque, whitish or greenish, sometimes foamy - consists of purulent fractions, a lot of mucus and small air bubbles. The middle layer is greyish, more transparent liquid. The lower layer is greenish-yellow, loose, flaky, consisting of detritus and purulent bodies.