Версия сайта для людей с нарушением зрения
только для медицинских специалистов

Консультант врача

Электронная медицинская библиотека

Раздел 11 / 18
Страница 1 / 1

Chapter 10. LUNG DISEASES

ANATOMY OF THE LUNGS

FUNCTIONS OF THE LUNGS

CLASSIFICATION OF LUNG AND PLEURA DISEASES

Instrumental methods (functional and structural)

Functional methods

These detect functional condition of respiratory and circulatory systems, their reserve capabilities in the choice of tactics of treatment, extent and method of the operation.

Spirometry

It determines the basic indices of external respiration by means of lung volumes' measuring with the help of spirometer:

- vital capacity of the lungs (VCL) - the volume of the air exhaled after maximum deep inspiration (normally 3.5-5.5 l);

- minute respiratory volume (MRV) - the volume of the air exhaled during 1 minute at quiet respiration (normally 6-8 l/min);

- maximum lung ventilation (MLV) - the volume of the air exhaled during 1 minute at maximum respiratory rate and depth (normally 110-120 l/min);

- tidal lung volume - the volume of the air remaining in the lungs after maximum expiration.

Watchal-Tiffno's test is the test for evaluation of tracheobronchial patency. Percentage ratio of the volume of the air exhaled after maximum inspiration during the first second of the forced expiration to the vital capacity of the lungs is calculated (normally 70-80%).

Analysis of the blood gases

It is the most accurate method of the respiratory organs' function evaluation, of respiratory insufficiency identification. This method determines the basic gasotransport lung function indices with the help of:

1. gas analyzer:

- partial oxygen pressure pO2 (normally 90-120 mm Hg);

- partial carbon dioxide pressure pCO2 (normally 34-46 mm Hg);

- pH of blood (normally 7.35-7.45);

- bicarbonates' content in blood HCO3 (normally 22-26 mequiv/l).

2. The analysis allows assessing:

- acidosis - pH < 7.35

- alkalosis - pH > 7.45

- hypercapnia - pCO2 > 46 mm Hg

- hypocapnia - pCO2 < 34 mm Hg

- hypoxemia - pO2 < 90 mm Hg

3. pulsoximeter:

- saturation - satiation of hemoglobin with oxygen in erythrocytes - SaO2 (normally 95-98%).

In respiratory insufficiency the content of oxygen in hemoglobin decreases below 95% (hypoxemia).

Structural methods.

These determine the type of the pathological process (tumor, inflammation, etc.),

its localization and spread.

Survey roentgenography of the chest

It is performed in two projections - direct and lateral and provides information on the character and details of the pathological process. In some cases it may be the final method of examination. More frequently X-ray is the basis for working out the further plan of the patient's examination with application of special techniques.

Tomography

It is a layer-by-layer X-ray investigation of the lungs. It reveals the change of the lumen of the trachea and bronchi, presence of neoplasms in them, presence of cavities in the areas of the lung shadowing and detects the depth of the pathological shadow localization.

Computer tomography (CT)

It is the X-ray imaging of the tissue and thoracic organs' sections with high resolving capability. CT detects pathology in the pulmonary tissue, trachea, bronchi, mediastinal lymphatic nodes, spread of the process, its interrelations with other organs, presence of exudate in the pleural cavity and alterations of the pleura in tumors.

Magnetic resonance imaging (MRI)

It additionally detects vascular pathology without contrasting. It differentiates between tumors, cysts and vascular neoplasms. MRI determines invasion of the tumor into the surrounding structures, mediastinum, chest.

Bronchography

It is the contrasting roentgenological investigation of the bronchial tree. It reveals changes in bronchi: bronchiectases, cavities after the lung abscess, broncho-pleural fistulas, scarry stenoses of the bronchi.

Angiography

It is the contrasting roentgenological investigation of the pulmonary vessels. It verifies operability in lung cancer, diagnoses thromboembolism of the pulmonary artery. It is most informative in combination with CT.

Radioisotopic (radio-nuclide) investigation

It detects impairments of the blood flow and lung function. It reveals pathological foci in the lung, impairment of pulmonary tissue perfusion in atelectasis, tumor, metastases.

Ultrasonic investigation (US)

It detects subpleural neoplasms, exudate in the pleural cavity. Puncture of the lungs and pleura is performed under US-control in order to evacuate exudate, to obtain the material for cytological and microbiological investigation.

Bronchoscopy

It is the investigation of the bronchi with the help of fibrobronchoscope. It is the basic method of investigation in the diseases of trachea and bronchi. The imaging may be transmitted onto the monitor display. It visualizes pathological neoplasms in the trachea and bronchi. It allows obtaining sputum and tissue for bacteriological and morphological investigation.

Thoracoscopy

It is an endoscopic investigation with application of the optical tube (thoracoscope) introduced into the pleural cavity with the help of the trochar. The imaging is transmitted onto the monitor display. It visualizes pathological processes in the pleural cavity. It allows obtaining fluid and tissue for bacteriological and morphological investigation. It is applied together with special instruments for manipulations and operations in the pleural cavity.

ACUTE BACTERIAL DESTRUCTIONS OF THE LUNGS

Definition and statistical data

Acute bacterial destructions of the lungs manifest themselves basically by primary purulent-necrotic foci in the form of an acute abscess or lung gangrene.

95-97% of patients have primary lung destruction. Among the patients there prevail men at the age of 30-35 years. Women fall ill 6-7 times more seldom. Incidence of acute lung destructions in pneumonias is observed in 2-5% of cases. Trauma of the chest gets complicated by destruction in 1.5-2.5% of the patients. Mortality rate in acute lung abscesses varies from 7% to 28%, and in gangrene it reaches 30-80%.

Acute abscess is an acute purulent-destructive inflammatory process characterized by the presence of separated purulent lung cavity surrounded by an infiltrate. Lung gangrene is a non-separated (without demarcation) purulent-necrotic process of the lung tissue portion with the tendency to spread onto the lobe or the whole lung.

Clinical picture of acute bacnerial destructions of the lungs

Abscess and gangrene are of the same origin and have common typical signs and symptoms in the initial phase of disease development. With the further development of the disease the clinical picture begins to acquire specific features of either acute abscess or gangrene.

There are three periods in the clinical picture of acute lung abscess:

1 period (initial stage) is the formation of a closed pulmonary abscess;

2 period is the breaching of the abscess into the bronchus, formation of an open abscess accompanied by improving of the condition.

3 period - clinical outcome: complete cure, clinical cure, the transition into a chronic abscess.

In gangrene there is no periodicity, the patient's condition progressively becomes worse. Intoxication aggravates, it is accompanied by disturbance of consciousness and leads to the development of septic shock and polyorganic insufficiency.

Variants of clinical course of stage 2 of the abscess

Variants of clinical course of developing lung gangrene

In the most favourable course of the disease all clinical manifestations may be liquidated during 5-7 days following the opening of the abscess into the bronchial tree. A scar is formed at the site of the abscess and complete recovery occurs.

In a part of the patients the purulent-inflammatory process is liquidated but a dry residual cavity is formed which is considered as "a clinical recovery".

In 2-8% of the patients chronic abscess is formed. It is considered to occur 2 months after the onset of the disease. Presence of the cavity of more than 6 cm, poor conditions for acute abscess drainage (presence of sequesters in the cavity, localization in the lower lobe, narrow draining bronchus), as well as inadequate treatment, reduced reactivity of the organism contribute to the chronic abscess formation.

In most favourable course of gangrene the area of necrosis may be separated and the disease tales the course of chronic abscess.

Most frequently separation does not occur and gangrene progresses. There inevitably develop complications in the form of empyema of the pleura, pyopneumothorax, hemorrhage, bronchial fistulas, polyorganic insufficiency, sepsis.

Multiple abscesses (staphylococcal destruction, aspiration pneumonia) take the most severe course. Because of the lack of drainage into the bronchus the clinical course resembles that of gangrene

Features of clinical picture of acute bacterial lung destruction, complicated by pleural empyema

Total and subtotal empyema

severe pain and shortness of breath, acrocyanosis, forced sitting posture; lag in breathing affected half of the breast; smoothing and expansion of intercostal spaces;

the weakening or absence of voice tremor and respiratory sounds, percussion definition of fluid in the pleural cavity through Ellis - Demuazo line (over 250 ml);

displacement of mediastinum in a healthy side.

Localized empyema

All types are accompanied by local pain and shortening of percussion sound in the accumulation of pus;

At a basal empyema pain is localized in the lower part of the chest, hypochondrium and irradiate in a shoulder-blade, shoulder; At the apical empyema the swelling of the shoulder and shoulder girdle, a cervical plexitis, Bernard-Horner's syndrome are possible.

Pyopneumothorax

At the burst in the pleural cavity the pleuropulmonary shock is possible; dull percussion sound above an accumulation of pus and tympanic sound above an accumulation of air;

In the presence of a bronchopleural fistula - amphoric breath sounds.

Differential diagnostics

Sign

Acute purulent destruction of the lungs

Lung cancer

Cavernous tuberculosis

Suppurated cysts of the lung

Bronchiectasias

Age

More frequently males Older than 40 y.o.

Any age

More frequently children

Anamnesis vitae

Antisocial life style.

Alcoholism, narcomania, AIDS

Smoking. Effect of harmful environmental factors

Contact with patients ill with tuberculosis. Alcoholism, narcomania,

AIDS

Contact with animals

Frequent ca-tarrhal diseases

Anamnesis morbi

Acute onset of the disease

The disease develops slowly

Pulmonary anamnesis from the childhood

Roentgenography

The focus of the pulmonary tissue destruction surrounded by an infiltrate

Cavities of various size are likely to be localized in the centre of the tumor with irregular tuberous contours.

The cavity with horizontal level of liquid, with regular inner contours, surrounded by a narrow zone of inflammatory infiltration

Circular form of cavities with distinct smooth contours, presence of horizontal level of liquid.

Intensified picture of the lungs, enlarged lymph nodes. In severe course of the disease - netlike, socket-like picture

Investigation of the sputum

Leukocytes, elastic fibers, bacteria

Atypical cells

Mycobacteria of tuberculosis

Leukocytes, elastic fibers, bacteria

Bronchoscopy

Edema, hyperemia of the mucosa (exacerbation stage)

Narrowing and deformation of the bronchus wall in central cancer

Edema, hyperemia of the mucosa

Bronchography

The cavity of destruction in case of communication with the bronchus

Narrowing and infiltration of the bronchus in central cancer

The cavity of destruction in case of communication with the bronchus

Presence of saclike or cylindrical bronchiectasias

BRONCHIECTASIAS. BRONCHIECTATIC DISEASE

Definition and statistical data

Bronchiectasias are congenital or acquired pathological enlargements of some sections of the bronchi associated with pathological changes of their walls' structure. Bronchiectatic disease may be considered as suppuration of congenital bronchiectases or as a variant of treatment of chronic pneumonia accompanied by bronchiectasias' formation.

Frequency of bronchiectasias is evaluated by various investigators from 0.4 to 5%. Among all broncho-pulmonary diseases frequency of bronchiectasias accounts for 10-30%. Bronchiectases occur at any age, more frequently in females. Not less than 50% of bronchiectasias in adults - are congenital. Unilateral damages account for 70%, bilateral damages - for 30%. Segments of the left lung lower lobes are impaired more frequently.

Differential diagnostics

Bronchiectatic disease should be differentiated from lung abscesses, central carcinoma and tuberculosis of the lungs, in which bronchiectases are secondary and are caused by the bronchus obstruction.

Bronchiectatic disease differs from the mentioned diseases by:

- significantly longer duration of the disease with characteristic exacerbations;

- a large amount of the discharged sputum, lack of tuberculosis mycobacteria and atypical cells in the sputum;

- more frequent localization of the process in the lower lobe.

SPONTANEOUS PNEUMOTHORAX

Definition and statistical data

Pneumothorax is a pathological condition characterized by accumulation of air in the pleural cavity as a result of a trauma of the lungs and thoracic cavity (including operation trauma) due to the impairment of the unity of visceral, parietal or mediastinal pleura, intentional introduction of the air into the cavity with therapeutic purpose, as well as due to "spontaneous" rupture of the lung.

Spontaneous pneumothorax occurs due to imaginary spontaneous rupture of the lung, more frequently in persons not awaring of previously existing pulmonary diseases.

Incidence of spontaneous pneumothorax occurrence is 5 per 100 000 of the population (males - 7.4; females - 1.2 per 100 000), accounting for 7.4 among males and 1.2 - among females per 100 000 citizens. It is more frequently observed in persons of 20-40 years of age.

LUNG CANCER

ECHINOCOCCOSIS OF THE LUNGS

Definition and statistical data

Echinococcosis is the lesion of the lungs with the tapeworm Echinococcus granulosus in the cystic stage of the development.

Lesions of the lungs account for about 25% of cases among other localizations of echinococcal cysts. Echinococcosis of the lungs most frequently occurs in Kazakhstan, Turkmenistan, Tajikistan, Kirgyzstan, in Russia - in the regions of the Volga river, Northern Caucases, where the population is traditionally engaged in cattle breeding.

Для продолжения работы требуется вход / регистрация