Mechanism of development of pneumonia
Pathways of penetration of pathogens into the lung parenchyma:
The bronchogenic pathway is considered the most common. Microorganisms get into bronchioles with inhaled air, especially if there is any inflammatory nasal lesion: the swollen mucosa with the ciliated epithelium due to inflammation can not hold germs, and the air is not fully purified. It is possible to spread the infection from a chronic foci found in the pharynx, nose, sinuses, tonsils, into the lower parts of the respiratory tract. The development of pneumonia is also facilitated by aspiration, various medical manipulations, for example intubation of the trachea or bronchoscopy.
The hematogenous path is detected much less often. Penetration of microbes into lung tissue with blood flow is possible with sepsis, intrauterine infection or intravenous injection of narcotic drugs.
The lymphogenous path is the rarest. In this case, the pathogens first penetrate into the lymphatic system, then with the current of the lymph are carried throughout the body.
In one of the above pathogens, pathogenic agents enter mucosal respiratory bronchioles, where they precipitate and begin to multiply, leading to the development of acute bronchiolitis or bronchitis. If the process is not stopped at this stage, the microbes through interalveolar septa extend beyond the terminal branches of the bronchial tree, provoking focal or diffuse inflammation of the interstitial tissue of the lung. In addition to segments of both lungs, the process affects bifurcation, paratracheal and bronchopulmonary regional lymph nodes.
Violation of bronchial conduction ends with the development of emphysema – the foci of pathological expansion of the air cavities of the distal bronchioles, as well as atelectasis – the collapse of the affected area or lobe of the lung. In the alveoli, mucus is formed, which prevents the exchange of oxygen between the vessels and the tissue of the organ. As a result, respiratory failure develops with oxygen starvation, and in severe course – heart failure.
Inflammation of the viral nature often leads to desquamation and necrosis of the epithelium, inhibiting humoral and cellular immunity. The formation of an abscess is typical for pneumonia caused by staphylococci. In this purulent necrotic focus contains a large number of microbes, along its perimeter there are zones of serous and fibrinous exudates without staphylococci. Inflammation of serous nature with the spread of pathogens that multiply in the inflammation zone is typical for pneumonia caused by pneumococci.
Classification of pneumonia
According to the classification used, pneumonia is divided into several species, forms, stages.
Depending on the etiology of pneumonia happens:
Based on epidemiological data:
- In the recipient with a transplanted organ.
- With immunodeficiency;
- Without compromising immunity.
Concerning clinical and morphological manifestations:
Depending on the nature of the course of the disease:
- Acute lingering;
Based on the spread of the process:
Concerning the mechanism of development of pneumonia happens:
Given the presence or absence of complications:
The severity of the course of the inflammatory process:
- Moderate severity;
Symptoms of pneumonia
Almost every type of pneumonia has the characteristic features of the flow, due to the properties of the microbial agent, the severity of the course of the disease and the presence of complications.
Croupous pneumonia begins suddenly and acutely. The temperature reaches a maximum in a short time and lasts up to 10 days, accompanied by chills and severe symptoms of intoxication – headaches, arthralgia, myalgia, severe weakness. The face looks haggard with cyanosis of the lips and the area around them. A fever flush appears on his cheeks. It is possible to activate the herpes virus, which constantly finds in the body, which is manifested by herpetic eruptions on the wings of the nose or the lip of the lips. The patient is concerned about chest pain on the side of the inflammation, shortness of breath. Cough at first dry, “barking” and unproductive. From the 2nd day of inflammation during coughing, vitreous sputum of a viscous consistency with blood veins begins to flow away, then perhaps uniform staining with blood, because of what it acquires a red-brown color. The amount of detachable increases, sputum becomes more diluted.
At the onset of the disease, breathing can be vesicular, but weakened due to the forced restriction of the person’s respiratory movements and the defeat of the pleura. Approximately on 2-3 days at auscultation various varieties of dry and wet wheezing are heard, crepitation is possible. In the future, as the fibrin accumulates in the alveoli, the percussion sound is dulled, crepitus disappears, bronchophonia intensifies, bronchial breathing appears. The dilution of exudate leads to a decrease or disappearance of bronchial respiration, the return of crepitus, which becomes more coarse. Dilution of mucus in the respiratory tract is accompanied by severe vesicular breathing with wet rales.
In severe conditions, an objective examination reveals rapid, rapid breathing, deaf heart sounds, a frequent arrhythmic pulse, and lowering of blood pressure.
On average, the febrile period lasts no longer than 10-11 days.
Focal pneumonia is characterized by a different clinical picture. The inconspicuous onset of the disease with a gradual wave-like course is due to the different stages of development of the inflammatory process in the foci of the affected segments of the lung. At a mild degree, the temperature does not exceed 38.0 ° C with fluctuations during the day, accompanied by sweating. The heart rate corresponds to the temperature in degrees. With moderate pneumonia, the febrile temperature is higher – 38.7-39.0 ° C. The patient complains of pronounced dyspnea, chest pain when coughing, inhaling. Cyanosis and acrocyanosis are observed.
At auscultation, breathing is hard, sonorous dry or wet small, medium or large bubbling rales can be heard. With a central location of the focus of inflammation or deeper than 4 cm from the surface of the body, increased vocal tremor and dullness of percussion sound may not be determined.
The purity of atypical forms of pneumonia with the erased clinical picture and the absence of some characteristic features has increased.
Complications and possible consequences of pneumonia
The course of the disease and its outcome largely depend on the developed complications, which are divided into extrapulmonary and pulmonary.
Extrapulmonary complications of pneumonia:
- atelectasis of the lung;
- parapneumonic exudative pleurisy;
- abscess or gangrene of the lung;
In the severe form of acute pneumonia with extensive damage and destruction of lung tissue, the effects of exposure to toxins develop:
- Acute cardiac, respiratory and / or hepatic insufficiency;
- Pronounced shift of acid-base balance;
- Shock is infectious-toxic;
- Thrombohemorrhagic syndrome;
- Failure of the kidneys.
Treatment of pneumonia
The moderate and severe course of pneumonia requires admission to the therapeutic or pulmonology department. Uncomplicated pneumonia of mild degree can be treated on an outpatient basis under the supervision of a district therapist or a pulmonologist physician visiting a patient at home.
Bed rest with a plentiful drink and a balanced, sparing diet should be observed for the entire period of fever and severe intoxication. The room or ward where the patient is located should be regularly ventilated and quartzed.
The most important in the treatment is etiotropic therapy, aimed at the destruction of the causative agent of the disease. Proceeding from the fact that pneumonia of bacterial genesis is more often diagnosed, etiotropic treatment of the disease of this nature of origin consists of a course of antibacterial therapy. The choice of the drug or a combination thereof is performed by the attending physician based on their condition and age of the patient, the severity of the symptoms, the presence or absence of complications and individual characteristics, for example, drug allergy. The multiplicity and method of administration of an antibiotic is chosen, based on the severity of the course of pneumonia, more often this parenteral (intramuscular) administration.
For the treatment of pneumonia, antibiotics of the following pharmacological groups are used:
- Semisynthetic penicillins – oxacillin, carbenicillin, amoxiclav, ampiox, ampicillin;
- Macrolides – sumamed, rovamycin, clarithromycin;
- Lincosamides – lincomycin, clindamycin;
- Cephalosporins – ceftriaxone, cefazolin, cefotaxime and others;
- Fluoroquinolones – avelox 400mg, ciprobay, moxifloxacin;
- Aminoglycosides – gentamicin, amikacin or kanamycin;
- Carbapenems – meronem, meropenem, tienam.
The average duration of the course varies between 7-14 days, sometimes longer. During this period, it is possible to replace some drugs with others.
The basis of etiotropic treatment of pneumonia of fungal genesis are antifungal drugs, viral – antiviral drugs.
- Antipyretics for lowering temperature;
- Mucolytics and expectorants for liquefaction and excretion of sputum;
- Antihistamines for blockade of histamine receptors and removal of allergization manifestations;
- Bronchodilators for bronchial dilatation, restoration of drainage and elimination of dyspnea;
- Immunomodulatory therapy for anti-infection protection and stimulation of immunogenesis;
- Detoxication therapy, which removes intoxication;
- Corticosteroids for the removal of inflammation.
Physiotherapy procedures after temperature normalization:
- UHF and SHF;
- Paraffin therapy;
Therapeutic measures are carried out until the patient recovers, which is confirmed by objective methods – auscultation, normalization of laboratory and radiologic studies.
Prevention of pneumonia
- Hardening of the body;
- Strengthening immunity;
- Sanation of chronic foci of infection;
- Timely treatment of caries;
- Avoidance of hypothermia;
- Refusal from smoking and alcohol abuse;
- Fighting dust;
- Change of place of work if it is associated with harmful production;
- Exclusion of contacts with allergens.