Chronic bronchitis (chronic bronchitis) is a chronic non-specific inflammation of the trachea, bronchial mucosa and surrounding tissues. Clinically, cough and sputum are the main symptoms, and the onset lasts for 3 months each year for 2 or more years. Other diseases with symptoms of cough, cough and wheezing (e.g. tuberculosis, pneumoconiosis, lung abscess, heart disease, cardiac insufficiency, bronchiectasis, bronchial asthma, chronic nasopharyngitis, esophageal reflux syndrome and other disorders) were excluded.
Etiology and pathogenesis
The etiology of the disease is not fully understood and may be the result of long-term interaction of multiple factors.
1, harmful gases and harmful particles such as cigarettes, smoke, dust, irritant gases (sulfur dioxide, nitrogen dioxide, chlorine, ozone, etc.). These physicochemical factors can damage airway epithelial cells, causing cilia movement to be reduced and macrophage phagocytosis to be reduced, leading to a decrease in airway purification function. It also stimulates the submucosal receptors and makes the parasympathetic nerves hyperfunctional, causing bronchial smooth muscle contraction, glandular hypersecretion, cupped cell hyperplasia, increased mucus secretion, and increased airway resistance.
Cigarette smoke can also increase the production of oxygen radicals, induce neutrophils to release proteases, inhibit the antitrypsin system, destroy lung elastic fibers, and trigger the formation of emphysema.
2, infection factors virus, mycoplasma, bacteria and other infections is one of the important reasons for the development of chronic bronchitis. Viral infections are common with influenza virus, rhinovirus, adenovirus and respiratory syncytial virus. Bacterial infections are often secondary to viral infections, with common pathogens such as Streptococcus pneumoniae, Haemophilus influenzae, Catamorax and Staphylococcus. These infectious factors also cause damage and chronic inflammation of the trachea and bronchial mucosa.
3, other factors Immunity, age and climate factors are related to chronic bronchitis. Cold air can stimulate the glands to increase mucus secretion, cilia movement is weakened, mucosal vasoconstriction, local blood circulation is impaired, which is conducive to secondary infection. Older adults have hyperalgesia, decreased cellular immune function, and reduced lysozyme activity, thus predisposing them to recurrent infections of the respiratory tract.
Pathology
Bronchial epithelial cells are degenerated, necrotic, and detached, with squamous epithelial hyperplasia, shortened cilia, adhesions, inversions, and loss of cilia in later stages. The mucosa and submucosa are congested and edematous, with hypertrophy and hyperplasia of the cupular cells and mucus glands, with high secretion and large amounts of mucus storage. Plasma cells and lymphocytes infiltrate and mild fibroplasia. As the disease continues to progress, the inflammation spreads from the bronchial wall to its surrounding tissues, the submucosal smooth muscle bundles may break and atrophy, the submucosal and peribronchial fibrous tissues proliferate, and the alveolar elastic fibers break, further developing into obstructive lung disease.
Clinical manifestations
(A) Symptoms
Slow onset, long duration of disease, repeated acute attacks and aggravation of the disease. The main symptoms are cough, sputum, or wheezing. Acute exacerbation refers to the sudden aggravation of cough, sputum and wheezing. The main cause of acute exacerbation is respiratory tract infection, and the pathogens can be viruses, bacteria, mycoplasma and chlamydia, etc.
1.Cough Generally morning cough is predominant, with bouts of cough or sputum discharge during sleep.
2. Coughing sputum is usually white mucus and plasma foamy, and may occasionally be bloody. The sputum discharge is more in the early morning, and can be stimulated after waking up or changing position.
3. Wheezing or shortness of breath Wheezing is often called wheezing bronchitis, and some of them may be combined with bronchial asthma. If it is accompanied by emphysema, it may be manifested as shortness of breath after labor or activity.
(B) Physical signs
In the early stage, there are no abnormal signs. During acute attack, dry or wet stalls can be heard in the back or at the base of both lungs.
(C) Laboratory tests
1.X-ray examination may not be abnormal in the early stage. Repeated attacks cause bronchial wall thickening, infiltration or fibrosis of inflammatory cells in fine bronchi or alveolar interstitium, manifested as thickened and disorganized lung texture, reticulated or striated or speckled shadows, obvious in both lower lung fields.
2, Respiratory function tests are not abnormal in the early stage. If there is small airway obstruction, the maximum expiratory flow rate – volume curve at 75% and 50% lung capacity, the flow rate is significantly reduced.
3.Blood tests may occasionally show an increase in total white blood cells and/or neutrophils in the case of bacterial infection.
4. Sputum examination may result in culture of pathogenic bacteria. Smear may reveal gram-positive or gram-negative bacteria, or a large number of destroyed leukocytes and destroyed cupped cells.
Diagnosis
Based on cough and sputum, or with wheezing, with onset lasting 3 months per year and for 2 or more years, and exclusion of other chronic airway diseases.
Differential diagnosis
1. Cough variant asthma Characterized by irritant cough, easily induced by dust, fumes, cold air, etc., often with family or personal history of allergic diseases. It is not effective for antibiotic treatment and can be differentiated by a positive bronchial excitation test.
2. Eosinophilic bronchitis has similar clinical symptoms, no obvious changes on X-ray or increased lung texture, and a negative bronchial excitation test, which is easily misdiagnosed clinically. Induced sputum examination with an increased percentage of eosinophils (≥ 3%) can be diagnosed.
3, pulmonary tuberculosis There are often symptoms such as fever, malaise, night sweats and wasting. Sputum for antacid bacilli and chest X-ray can be distinguished.
4.Bronchial lung cancer Most of them have several years of smoking history, persistent irritating cough or past history of cough, and recent change of cough nature, often with blood in sputum. Sometimes it manifests as repeated obstructive pneumonia at the same site, which fails to completely subside with antibacterial drug treatment. Sputum exfoliative cytology, chest CT and fiberoptic bronchoscopy are performed to clarify the diagnosis.
5. Interstitial pulmonary fibrosis has a slow clinical course, starting with only cough and sputum, and occasionally a feeling of shortness of breath. On close auscultation, a bursting sound can be heard in the lower posterior side of the chest (Velcro ancient Q-rules mackerel sweet cup mushroom file stop pontoon squeezing cup hoop brake spring fold).
6, bronchial dilatation Typical manifestation is repeatedly large amount of pus sputum, or repeatedly hemoptysis. x-ray chest radiographs are often coarse texture or curly hair in the lung field. High-resolution spiral CT examination is helpful for diagnosis.
Treatment
1.Treatment of acute exacerbation
(1) Infection control: antibacterial drug therapy can be used quinolones, macrolides, β-lactams or sulfonamides orally, and intravenous administration when the condition is severe. For example, levofloxacin 0.4g, once daily; roxithromycin 0.3g, twice daily; amoxicillin 2-4g/d, divided into 2-4 oral doses; cephalofuroxime 1.0g/d, divided into 2 oral doses; compound sulfamethoxazole (SMZ-co), 2 tablets each time, twice daily. If the pathogenic bacteria can be cultured, antibacterial drugs can be selected according to the drug sensitivity test.
(2) Cough suppressant and expectorant: Try 10ml of compound licorice combination, 3 times daily; or 10ml of compound chloride combination, 3 times daily; also add the expectorant drug bromohexine 8-16mg, 3 times daily; 30mg of aminoglutethimide hydrochloride, 3 times daily; 0.3g of myrtle oil, 3 times daily. For dry cough, cough suppressants such as dextromethorphan, noscapine or its combination are available.
(3) Asthma: Those with asthma can add antispasmodic and antiasthmatic drugs, such as aminophyllin 0.1g, 3 times a day, or theophylline controlled release, or long-acting β2 agonist plus glucocorticoid inhalation.
2.Treatment in remission
(1) Quit smoking and avoid the inhalation of harmful gases and other harmful particles.
(2) Enhance physical fitness and prevent colds, which is also one of the main elements in the prevention and treatment of chronic bronchitis.
(3) For recurrent respiratory infections, immunomodulators or Chinese herbal medicines, such as bacterial lysis products, BCG polysaccharide nucleic acid, thymidine, etc., can be tried, and some patients can see results.
Prognosis
Some patients can be controlled without affecting work and study; some patients can develop into obstructive lung disease or even pulmonary heart disease with poor prognosis. Pulmonary function changes in chronic bronchitis should be monitored in order to choose an effective treatment plan in time to control the development of the disease.