Acute obstructive bronchitis is an inflammation of the bronchial tree, accompanied by a syndrome of bronchial obstruction, mainly of small and medium caliber. The main symptom of acute obstructive bronchitis is expiratory shortness of breath , which occurs against the background of coughing, asthma attacks, fever, wheezing or wet wheezing. In addition to the data of the clinical picture, spirometry, pneumotachography, and x-ray of the lungs are used in diagnostics. Modern algorithms for the treatment of acute obstructive bronchitis include the use of bronchodilators, mucolytics, expectorants, inhaled glucocorticosteroids, massage.
Acute obstructive bronchitis is a clinical variant of acute bronchitis , which is characterized by impaired bronchial patency due to edema of the mucous membrane, accumulation of bronchial secretions and bronchial hyperreactivity. The disease is most common in childhood. According to research in the field of pulmonology and pediatrics , about 20-25% of all acute bronchitis in children occur with symptoms of bronchial obstruction. In addition to obstructive bronchitis, children often develop other acute obstructive syndromes: laryngotracheitis ( croup ), bronchiolitis , bronchial asthma… The criteria for acute obstructive bronchitis are persistence of symptoms of bronchial inflammation for up to 3 weeks in the presence of expiratory dyspnea.
Causes of Acute Obstructive Bronchitis
Most often, acute obstructive bronchitis has an infectious-allergic genesis. As a rule, the defeat of the lower respiratory tract is preceded by an acute respiratory viral infection: influenza , respiratory syncytial, rhinovirus, adenovirus, enterovirus infection , parainfluenza , etc. In this case, the actual bronchial obstruction often occurs in persons with a burdened allergic history.
The high prevalence of acute obstructive bronchitis among preschool children is due to anatomical and physiological prerequisites. The immune system of children of this age group is characterized by immaturity (insufficient secretion of interferons, immunoglobulins G and A, limited complement activity, immaturity of T and B lymphocytes, etc.), which is accompanied by an increased susceptibility to infections. Along with the peculiarities of the structure and functioning of the respiratory tract (small diameter of the bronchi, looseness of the mucous membrane, increased mucus secretion, mucociliary insufficiency, etc.), these factors create conditions for bronchial obstruction.
The mechanism of development of broncho-obstructive syndrome is associated with hyperplasia and edema of the mucous membrane of the respiratory tract and, to a lesser extent, with bronchospasm… Viral agents cause damage to the bronchial mucosa and trigger a chain of immunological reactions that result in the release of mediators. The latter (histamine, serotonin, leukotrienes, prostaglandins, etc.) cause increased vascular permeability, bronchial edema (with thickening of all layers of the bronchial wall), hypersecretion and increased viscosity of mucus, bronchial hyperreactivity. Ultimately, this leads to impaired airway patency. Some researchers consider bronchial obstruction as a protective mechanism preventing the penetration of infectious agents into the pulmonary parenchyma – observations show that acute obstructive bronchitis is rarely complicated by bacterial pneumonia.
Environmental factors that significantly increase the risk of bronchial obstruction include passive and active smoking, air pollution with inhalation irritants (gasoline vapors, ammonia, chlorine, sulfur dioxide), meteorological factors (cold air, high humidity or dry air). Acute obstructive bronchitis usually occurs in children who are often ill .
Symptoms of Acute Obstructive Bronchitis
The initial clinical picture is determined by the symptoms of the respiratory infection that gave rise to the development of acute obstructive bronchitis. Difficulty breathing appears already on the first or second (sometimes on the third or fifth) day. Respiratory rate increases to 25 or more per minute; exhalation becomes elongated, noisy, wheezing, audible at a distance (distant wheezing). The younger the child, the more pronounced the signs of respiratory failure (tachypnea, anxiety, perioral cyanosis, the desire to take a forced position).
Patients with acute obstructive bronchitis are worried about an unproductive, paroxysmal cough that gets worse at night. The participation of the auxiliary muscles in breathing is indicated by the retraction of the intercostal spaces and supraclavicular fossae, the inflation of the wings of the nose. Body temperature can be normal or subfebrile. The course of the infectious process is indicated by signs of a violation of general well-being: weakness, asthenia , headache, decreased appetite, increased sweating.
Symptoms of acute obstructive bronchitis persist for one to two to three weeks. When the episodes of the disease are repeated 2-3 times or more during the year, the diagnosis of ” recurrent obstructive bronchitis ” is made. Acute and recurrent broncho-obstructive syndrome can be complicated by the addition of bacterial inflammation, the formation of chronic obstructive bronchitis, deforming bronchitis, bronchial asthma.
Diagnostics of the acute obstructive bronchitis
Physical examination and analysis are usually sufficient to confirm the diagnosis. In favor of acute obstructive bronchitis is evidenced by its connection with a viral disease, the presence of tachypnea and prolonged expiration. The rib cage is enlarged in anteroposterior size; percussion over the lungs is determined by tympanitis. On auscultation, hard breathing with multiple whistling, buzzing rales is heard.
Radiography of the lungs reveals a bilateral increase in the pulmonary pattern and expansion of the roots, indicates an increased swelling of the lungs (flattening and low standing of the domes of the diaphragm, the horizontal position of the ribs, increased transparency of the pulmonary fields). Shifts in the peripheral blood correspond to a viral infection (neutrophilic leukocytosis, increased ESR). Blood gas indicators may be within normal limits or slightly changed.
Methods for studying the function of external respiration (spirometry, pneumotachography) indicate a decrease in VC and a violation of bronchial patency. Acute obstructive bronchitis requires differential diagnosis with acute bronchiolitis , whooping cough , bronchial asthma, and foreign bodies of the bronchi .
Treatment of acute obstructive bronchitis
Acute obstructive bronchitis is treated on an outpatient basis. Hospitalization is needed for young children with moderate and severe bronchial obstruction. A gentle regimen is prescribed, contact with irritants (perfume, dust, household chemicals, cigarette smoke, etc.) is excluded. In order to dilute sputum and facilitate its evacuation from the respiratory tract, a sufficient water regime, humidification of the air in the room, percussion massage of the chest, positional drainage are recommended .
Rational pathogenetic therapy avoids the development of severe forms of acute obstructive bronchitis and its chronicity. Therefore, the main role in the treatment is assigned to anti-inflammatory, bronchodilator and mucolytic drugs. Of the bronchodilators, aminophylline, theophylline are usually used; it is advisable to prescribe beta-2-adrenergic agonists (salbutamol, terbutaline) by inhalation or through a nebulizer . Bromhexine and ambroxol (in the form of syrup, tablets, inhalation) have mucolytic and expectorant effects. The regimen and dosages are selected by the pediatricianor a pulmonologist according to the patient’s age. As an anti-inflammatory therapy, it is recommended to use fenspiride, inhaled glucocorticosteroids. The appointment of centrally acting antitussives in acute obstructive bronchitis is undesirable.
Distracting procedures ( cupping massage , hot foot and hand baths ), physiotherapy ( UHF , laser , electrophoresis ) are effective . Severe forms of bronchial obstruction require oxygen therapy . Recombinant interferon preparations are used to combat pathogens of respiratory infection; antibiotic therapy is justified only if acute pneumonia is suspected .
Prediction and prevention of acute obstructive bronchitis
In about 30-50% of children with acute obstructive bronchitis, episodes of bronchial obstruction are repeated within a year against the background of a new viral infection. In most cases, the obstructive component disappears at the age of over 3-4 years. The presence of an allergic predisposition significantly increases the likelihood of chronic obstructive bronchitis. To reduce the risk of morbidity, hardening, limiting contact with infectious and allergic agents, and debridement of chronic infectious foci are recommended. With recurrent obstructive bronchitis, a consultation with an allergist-immunologist and a pulmonologist is indicated.