Acute bronchitis is a form of diffuse inflammation of the bronchial tree, characterized by increased bronchial secretion and impaired bronchial patency. Disease is characterized by a sharp onset, respiratory symptoms (runny nose, sore throat, paroxysmal cough with sputum, chest pain, shortness of breath, bronchospasm) and symptoms of intoxication (fever, headache, weakness). Physical examination data, lung radiography, laboratory tests, functional tests, ECG, bronchoscopy help in the diagnosis of acute bronchitis. Treatment is complex conservative; includes antiviral, antibacterial, antipyretic, antihistamine, mucolytic, expectorant and antispasmodic drugs, NSAIDs, glucocorticoids, physiotherapy.
J20 Acute bronchitis
Acute bronchitis is a widespread respiratory disease; it can develop as an independent process when inflammation is limited to the bronchi (primary bronchitis), or complicate other existing pathology (secondary bronchitis). According to the level of damage to the lower respiratory tract, disease is divided into: tracheobronchitis, bronchitis with a predominant lesion of medium-caliber bronchi, bronchiolitis. Almost all acute bronchitis refers to inflammatory processes of a diffuse nature; less often they are segmental (usually as a component of another acute local inflammatory process).
By the nature of the inflammatory exudate, catarrhal, mucous, purulent bronchitis are isolated. Most acute form is catarrhal in nature, purulent forms of the disease are rare, usually with a combination of viral and streptococcal infection.
In this disease, the inflammatory process can affect only the mucous membrane of the bronchi, in the case of a severe course, it affects deeper tissues: the submucosal and muscular layers. Pathological changes in the bronchial wall are characterized by edema and hyperemia of the mucous membrane, pronounced infiltration of the submucosal layer with hypertrophy of the muco-protein glands, an increase in the number of goblet cells, degeneration and a decrease in the barrier function of the ciliary epithelium. Serous, mucous or mucopurulent exudate is noted on the inner surface of the bronchi. Increased mucus secretion leads to impaired patency of small bronchi and bronchioles.
Causes of acute bronchitis
Depending on the etiological factor, acute bronchitis of infectious, non-infectious, mixed and unknown genesis is distinguished. The leading mechanism for the development of this disease is infection: the causative agents are viruses (ARVI, influenza and parainfluenza, measles, rubella), less often – bacteria (pneumococcus, Staphylococcus, mycoplasma, chlamydia, representatives of typhoparathyphosis group). Infectious agents can enter the bronchi by air, hematogenic and lymphogenic routes.
Respiratory syncytial viral infection plays a significant role in the etiology of this disease, which in most cases is accompanied by damage to the bronchial tree. Primary acute bacterial bronchitis occurs infrequently, usually there is a layering of a secondary bacterial infection on a viral one due to the activation of conditionally pathogenic microflora of the upper respiratory tract.
The cause of non-infectious form is physical and chemical factors (dust, smoke, cold or hot dry air, chlorine, ammonia, hydrogen sulfide, acid and alkali vapors). In addition, disease can develop with a combination of infection and the action of physico-chemical stimuli. Acute allergic bronchitis occurs, as a rule, in patients genetically predisposed to allergic reactions.
Factors that reduce the general and local resistance of the body and contribute to the occurrence of acute bronchitis are frequent hypothermia, harmful working conditions, smoking and alcoholism, foci of chronic infection in the nasopharynx and nasal breathing disorders, stagnation in the small circle of blood circulation, severe diseases, irrational nutrition. Pathology is more often observed in childhood and the elderly.
The inflammatory process in acute bronchitis of viral etiology usually begins in the upper respiratory tract: nasopharynx, tonsils, gradually spreading to the larynx, trachea, and then to the bronchi. Activation of conditionally pathogenic microflora aggravates catarrhal and infiltrative changes in the bronchial mucosa, causing a prolonged course or complications of acute bronchitis.
Symptoms of acute bronchitis
The features of the clinical picture depend on the causal factor, the nature, prevalence and severity of pathological changes, the level of damage to the bronchial tree, the severity of the inflammatory process.
The disease is characterized by an acute onset with signs of damage to the upper and lower respiratory tract, intoxication. Disease of infectious etiology is preceded by symptoms of acute respiratory viral infections – nasal congestion, runny nose, tickling and sore throat, hoarseness of voice. The development of general intoxication in acute bronchitis is manifested by chills, an increase in body temperature to subfebrile values, weakness, fatigue, headache, sweating, pain in the muscles of the back and extremities. With a mild course of acute bronchitis, there may not be a temperature reaction. Disesae caused by the causative agents of measles, rubella and whooping cough is accompanied by symptoms characteristic of the underlying disease.
The leading symptom is a dry painful cough that appears from the very beginning and lasts throughout the disease. Cough – paroxysmal, rough and sonorous, sometimes “barking”, intensifying the feeling of stinging and burning behind the sternum. Due to the overstrain of the pectoral muscles and spastic contraction of the diaphragm, pain appears in the lower chest and abdominal wall when coughing. Cough is accompanied by the separation of scanty and viscous sputum at first, then the nature of sputum gradually changes: it becomes less viscous and departs more easily, may have a mucopurulent character.
Severe and prolonged course is observed during the transition of the inflammatory process from the bronchi to the bronchioles, when a sharp narrowing or even closure of the bronchiolar lumen leads to the development of severe obstructive syndrome, impaired gas exchange and blood circulation. When joining acute bronchitis with bronchiolitis, the patient’s condition suddenly worsens: fever, pallor of the skin, cyanosis, sharp shortness of breath (40 or more breaths per minute), painful cough with scanty mucous sputum, first excitement and anxiety, then symptoms of hypercapnia (lethargy, drowsiness) and cardiovascular insufficiency (decreased blood pressure and tachycardia).
Acute allergic bronchitis is characterized by the association of the disease with exposure to an allergen, a pronounced obstructive syndrome with a paroxysmal cough, the release of light vitreous sputum. The development of this disease caused by inhalation of toxic gases is accompanied by chest tightness, laryngospasm, suffocation and painful cough.
The diagnosis of acute bronchitis is made by a therapist or a pulmonologist on the basis of clinical manifestations, as well as data from laboratory and instrumental studies. When examining a patient, it is necessary to take into account that acute bronchitis can be a manifestation of various infectious diseases (measles, whooping cough, etc.).
Auscultative data in acute bronchitis are characterized by hard breathing of the obstructive type, scattered dry wheezing. When liquid secretions accumulate in the bronchi, moist, small-bubbly wheezes can be heard, disappearing after vigorous coughing up sputum. In acute allergic bronchitis, there is an absence of mucopurulent and purulent sputum, a tendency to allergic reactions in the anamnesis.
In order to diagnose acute bronchitis, general, biochemical and immunological blood tests, urinalysis, lung x-ray, bronchoscopy, examination of the function of external respiration (spirometry, peak flowmetry), ECG and EchoCG, sputum culture for microflora are performed. The functional parameters of external respiration in acute bronchitis show a violation of pulmonary ventilation of the obstructive type. Changes in the blood picture include neutrophilic leukocytosis, acceleration of ESR; and in the case of allergic genesis of the disease – an increase in the number of eosinophils.
X-ray examination in the case of acute bronchitis of viral etiology reveals moderate expansion and indistinctness of the pattern of the roots of the lungs, with a prolonged course helps to detect the addition of complications (bronchiolitis, pneumonia). Differential diagnosis of acute bronchitis is carried out with bronchopneumonia, miliary pulmonary tuberculosis.
Treatment of acute bronchitis
In most cases, treatment of acute bronchitis is carried out on an outpatient basis, only in severe cases of the disease (for example, with severe obstructive syndrome or complicated by pneumonia) hospitalization in the department of pulmonology is necessary.
In acute bronchitis, accompanied by fever or subfebrility, bed rest is indicated, with adherence to a diet and copious drinking (heated alkaline mineral waters, herbal infusions), a ban on smoking. The room where the patient is located should be frequently and well ventilated with maintaining high humidity. For chest pains, you should use warming compresses, mustard plasters, jars on the sternum area, the interscapular area, mustard foot baths.
In the treatment of acute bronchitis against the background of acute respiratory viral infections, antiviral therapy (interferon, remantadine), antipyretic, painkillers, NSAIDs are used. Antibiotics or sulfonamides are prescribed only for secondary bacterial infection, with a prolonged course of acute bronchitis, with a pronounced inflammatory reaction.
In the case of a dry painful cough with this disease, codeine, dionin, libexin are taken in the first days of the disease, suppressing the cough reflex. With an increase in the sputum secreted, mucolytic and expectorant agents are shown to dilute it and improve drainage function: infusion of thermopsis herb, marshmallow, bromhexine, ambroxol, steam alkaline inhalations. It is recommended to take vitamins, immunomodulators. In case of obstruction, adrenolytics (ephedrine), antispasmodics (euffilin, papaverine) are used to relieve bronchospasm, according to indications – steroid hormones (prednisone). If necessary, intensive therapy of acute cardiac and respiratory failure is carried out.
In disease, physiotherapy methods are widely used (UFO, inductothermy of the interscapular region, chest diathermy, UHF), physical therapy, vibration massage. In the treatment of acute allergic bronchitis, antihistamines (clemastine, chloropyramine, mebhydroline), sodium cromoglycate, ketotifen are used, in severe cases glucocorticoids are indicated.
Uncomplicated acute bronchitis, as a rule, ends in clinical recovery within 2-3 weeks, while the restoration of functional parameters (respiratory function and bronchial patency) occurs within a month. With a prolonged course of acute bronchitis, clinical recovery occurs more slowly, approximately 1 -1.5 months after the onset of the disease.
Complications of acute bronchitis include obliterating bronchiolitis, bronchopneumonia, asthmatic bronchitis, in case of severe course in elderly and weakened patients, acute respiratory and heart failure is possible. Regularly recurring acute bronchitis contributes to the transition of the disease into a chronic form, with the progression of which the development of COPD, bronchial asthma, emphysema of the lungs is possible.
Prognosis and prevention
In acute catarrhal bronchitis, the prognosis is favorable, the disease ends, as a rule, with a complete restoration of the structure of the bronchial mucosa and absolute recovery. In the case of acute purulent bronchitis or the development of bronchiolitis, the prognosis worsens due to residual fibrous thickening of the bronchial wall and narrowing of the bronchial lumen. Violation of drainage function and deformation of the bronchial tree contribute to the protracted course of the disease and its chronization.
Prevention of acute bronchitis should consist in eliminating the possible cause of the disease (compliance with sanitary and hygienic standards at work, elimination of dust and gas pollution, quitting smoking and alcohol abuse, timely treatment of chronic infections and respiratory tract diseases, prevention of acute respiratory viral infections, hypothermia), increasing the body’s resistance.
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