Pneumosclerosis is a pathological replacement of connective lung tissue as a consequence of inflammatory or dystrophic processes in the lungs, accompanied by a violation of elasticity and gas exchange in the affected areas. Local changes are asymptomatic, diffuse – accompanied by progressive shortness of breath, cough, chest pain, fatigue. Radiography and computed/multispiral CT of the lungs, spirography, lung biopsy with morphological verification of the diagnosis are used to identify and assess the lesion. In the treatment, GCS, cytostatics, antifibrotic drugs, oxygen therapy, respiratory gymnastics are used; if necessary, the question of lung transplantation is raised.
ICD 10
J84.1 Other interstitial pulmonary diseases with mention of fibrosis
Meaning
Pneumosclerosis is a pathological process characterized by the replacement of the pulmonary parenchyma by non–functioning connective tissue. Pneumofibrosis usually develops in the outcome of inflammatory or dystrophic processes in the lungs. The proliferation of connective tissue in the lungs causes deformation of the bronchi, sharp compaction and wrinkling of the lung tissue. The lungs become airless and shrink in size. Disease can develop at any age, more often this lung pathology is observed in men over 50 years old. Since sclerotic changes in the lung tissue are irreversible, the disease is steadily progressing, can lead to profound disability and even death of the patient.
Classification
According to the degree of severity of the replacement of the pulmonary parenchyma with connective tissue, there are:
- pneumofibrosis – severe limited changes in the lung parenchyma alternating with air lung tissue;
- pneumosclerosis (actually pneumosclerosis) – compaction and replacement of lung parenchyma with connective tissue;
- pneumocyrrosis is an extreme case of pneumosclerosis, characterized by complete replacement of the alveoli, vessels and bronchi with connective tissue, pleural compaction, displacement of mediastinal organs to the affected side.
According to the prevalence in the lungs, disease can be limited (local, focal) and diffuse. Limited pneumosclerosis can be small- and large-focal. Limited disease macroscopically represents a section of the compacted pulmonary parenchyma with a decrease in the volume of this part of the lung. A special form of focal pneumosclerosis is carnification (post-pneumonic sclerosis, in which the lung tissue in the focus of inflammation resembles raw meat in appearance and consistency). Microscopic examination in the lung can determine sclerosed suppurative foci, fibroatelectasis, fibrinous exudate, etc.
Diffuse pneumosclerosis affects the whole lung, and sometimes both lungs. The lung tissue is compacted, the volume of the lungs is reduced, their normal structure is lost. Limited pneumosclerosis does not significantly affect the gas exchange function and elasticity of the lungs. With diffuse lung damage with pneumosclerosis, a picture of a rigid lung and a decrease in its ventilation is observed.
According to the predominant lesion of certain lung structures, alveolar, interstitial, perivascular, perilobular and peribronchial pneumosclerosis are distinguished. According to etiological factors, postnecrotic, dyscirculatory pneumosclerosis, as well as sclerosis of the lung tissue, developed as a result of inflammatory and dystrophic processes, are distinguished.
Causes of pneumosclerosis
Usually, pneumosclerosis accompanies the course or serves as the outcome of some lung diseases:
- unresolved infectious, viral and aspiration pneumonia, tuberculosis, mycoses;
- COPD, chronic bronchitis and peribronchitis;
- atelectasis of the lung, prolonged massive pleurisy;
- pneumoconiosis caused by inhalation of industrial gases and dust, radiation damage;
- alveolitis (fibrosing, allergic);
- sarcoidosis of the lungs;
- foreign bodies in bronchus;
- injuries and wounds of the chest and pulmonary parenchyma;
- hereditary lung diseases.
Insufficient volume and effectiveness of anti-inflammatory therapy of these diseases can lead to the development of pneumosclerosis.
Also, disease can develop as a result of hemodynamic disorders in the circulatory system (as a consequence of mitral stenosis, left ventricular heart failure, pulmonary embolism), as a result of ionizing radiation, taking toxic pneumotropic drugs, in patients with reduced immune reactivity.
Post-pneumonic pneumosclerosis develops as a result of incomplete resolution of inflammation in the lungs, leading to the proliferation of connective scar tissue and obliteration of the lumen of the alveoli. Especially often, pneumosclerosis occurs after staphylococcal pneumonia, accompanied by the formation of necrosis of the pulmonary parenchyma and the formation of an abscess, the healing of which is accompanied by the proliferation of fibrous tissue. Post-tuberculosis form is characterized by the proliferation of connective tissue in the lungs and the development of parotid emphysema.
Chronic bronchitis and bronchiolitis cause the development of diffuse peribronchial and perilobular pneumosclerosis. With long-term pleurisy, the surface layers of the lung are involved in the inflammatory process, compression of the parenchyma exudate occurs and the development of pleurogenic pneumosclerosis. Fibrosing alveolitis and radiation injuries cause the development of diffuse pneumosclerosis with the formation of a “cellular lung”. With the phenomena of cardiac left ventricular insufficiency, mitral valve stenosis, the liquid part of the blood sweats into the lung tissue with the further development of cardiogenic pneumosclerosis.
The mechanisms of development and forms of pneumosclerosis are due to its causes. However, violations of the ventilation function of the lungs, the drainage capacity of the bronchi, blood circulation and lymph in the lungs are common to all etiological forms of pneumosclerosis. Violation of the structure and destruction of the alveoli leads to the replacement of morphofunctional structures of the pulmonary parenchyma by connective tissue. Violation of lymph and blood circulation, accompanying bronchopulmonary and vascular pathology, also contribute to the occurrence of pneumosclerosis.
Symptoms of pneumosclerosis
Limited pneumosclerosis usually does not bother patients, sometimes there is a slight cough with scant sputum. When examined on the side of the lesion, chest sinking may be detected.
Diffuse pneumosclerosis is symptomatically manifested by shortness of breath – at first with physical exertion, and later – at rest. Skin with a cyanotic tinge due to reduced ventilation of the alveolar lung tissue. A characteristic sign of respiratory failure in this disease is a symptom of Hippocratic fingers (in the form of drumsticks). Diffuse pneumosclerosis is accompanied by the phenomena of chronic bronchitis. Patients are concerned about cough – at first rare, then intrusive with the release of purulent sputum. The course of pneumosclerosis worsens the main disease: bronchiectatic disease, chronic pneumonia. There may be aching chest pains, weakness, weight loss, increased fatigue.
Often there are signs of cirrhosis of the lung: gross deformation of the chest, atrophy of the intercostal muscles, displacement of the heart, large vessels and trachea towards the lesion. With diffuse forms of pneumosclerosis, hypertension of the small circulatory circle and symptoms of the pulmonary heart develop. The severity of the course of pneumosclerosis is determined by the volume of the affected lung tissue.
Morphological changes in the alveoli, bronchi and vessels in this disease lead to violations of the ventilation function of the lungs, arterial hypoxemia, reduction of the vascular bed and are complicated by the development of the pulmonary heart, chronic respiratory failure, and the addition of inflammatory lung diseases. A constant companion is emphysema of the lungs.
Diagnosis
Physical data in pneumosclerosis depend on the localization of pathological changes. Over the affected area or diffusely, sharply weakened breathing, wet and dry wheezing is heard, the percussion sound is dull.
Lung radiography can reliably detect pneumosclerosis. With the help of radiography, changes in the lung tissue are detected in the asymptomatic course of pneumosclerosis, their prevalence, nature and degree of severity. To detail the condition of the affected areas with pneumosclerosis, bronchography, CT of the lungs and MRI are performed.
Radiological signs of pneumosclerosis are diverse, since they reflect not only sclerotic changes in the lungs, but also the picture of concomitant diseases: emphysema of the lungs, chronic bronchitis, bronchiectasis. Radiographs show a decrease in the size of the affected part of the lung, strengthening, reticulation and looping of the pulmonary pattern along the branching of the bronchi due to deformation of their walls, sclerosis and infiltration of peribronchial tissue. Often, the pulmonary fields of the lower parts take the form of a porous sponge (“cellular lung”). On bronchograms – convergence or deviation of the bronchi, their narrowing and deformation, small bronchi are not determined.
Bronchoscopy often reveals bronchiectasis, signs of chronic bronchitis. Analysis of the cellular composition of the bronchial flushing makes it possible to clarify the etiology and degree of activity of pathological processes in the bronchi. In the study of the function of external respiration (spirometry, peak flowmetry) a decrease in the vital capacity of the lungs and the bronchial patency index (Tiffno index) are revealed. Blood changes in pneumosclerosis are nonspecific.
Treatment of pneumosclerosis
Treatment of pneumosclerosis is carried out by a pulmonologist or therapist. Acute inflammatory process in the lungs or the development of complications may become an indication for inpatient treatment in the department of pulmonology. In the treatment of pneumosclerosis, the main emphasis is on the elimination of the etiological factor.
Limited forms of pneumosclerosis that do not manifest themselves clinically do not require active therapy. If disease occurs with exacerbations of the inflammatory process (frequent pneumonia and bronchitis), antimicrobial, expectorant, mucolytic, broncholytic agents are prescribed, therapeutic bronchoscopy is performed to improve the drainage of the bronchial tree (bronchoalveolar lavage). With the phenomena of heart failure, cardiac glycosides and potassium preparations are used, in the presence of an allergic component and diffuse pneumosclerosis – glucocorticoids.
Good results in pneumosclerosis are provided by the use of a therapeutic and physical complex, chest massage, oxygen therapy and physiotherapy. Limited pneumosclerosis, fibrosis and cirrhosis, destruction and suppuration of lung tissue require surgical treatment (resection of the affected part of the lung). A new technique in the treatment of pneumosclerosis is the use of stem cells that allow restoring the normal structure of the lungs and their gas exchange function. In case of gross diffuse changes, lung transplantation becomes the only method of treatment.
Prognosis and prevention
Further prognosis in pneumosclerosis depends on the progression of changes in the lungs and the rate of development of respiratory and heart failure. The worst options for pneumosclerosis are possible as a result of the formation of a “cellular lung” and the addition of a secondary infection. When a “cellular lung” is formed, respiratory insufficiency becomes sharply heavier, the pressure in the pulmonary artery increases and the pulmonary heart develops. The development of secondary infection, mycotic or tuberculous processes against the background of pneumosclerosis often leads to death.
Measures for the prevention of pneumosclerosis include the prevention of respiratory diseases, timely treatment of colds, infections, bronchitis, pneumonia, pulmonary tuberculosis. It is also necessary to observe precautions when interacting with pneumotoxic substances, taking pneumotoxic drugs. In harmful industries associated with the inhalation of gases and dust, it is necessary to use respirators, install exhaust ventilation in mines and at the workplaces of glass carvers, grinders, etc. If signs of pneumosclerosis are detected in an employee, it is necessary to transfer to another place of work that is not associated with contact with pneumotoxic substances. Smoking cessation, hardening, light physical exercises improve the condition of patients with pneumosclerosis.
