Bacterial pneumonia is a microbial infection of the respiratory parts of the lungs, occurring with the development of intraalveolar exudation and inflammatory infiltration of the pulmonary parenchyma. Disease is accompanied by fever, weakness, headache, cough with mucopurulent or rusty sputum, shortness of breath, chest pain, myalgia and arthralgia, pulmonary insufficiency. The diagnosis is based on physical examination, lung radiography, general and biochemical blood tests, microscopy and sputum culture. The basis of the treatment is etiotropic antibiotic therapy.
J15 Bacterial pneumonia, not classified elsewhere
Bacterial pneumonia is an acute infectious and inflammatory process in the lung tissue caused by pathogenic microbial flora and characterized by the development of febrile, intoxication syndromes and respiratory failure. Among other etiological forms of lung inflammation (viral, parasitic, fungal, etc.), pathology confidently holds the first place. About 1000 people per 100 thousand of the population get sick with bacterial pneumonia every year. The most vulnerable group is children under 5 years of age and elderly people over 75 years of age. In pulmonology, the problem of pneumonia focuses on itself due to the steady increase in the number of cases of complicated course and the level of mortality.
What bacteria causes pneumonia
Bacterial pneumonia develops when the lungs are affected by gram-positive and gram-negative bacteria, many of which may be present in the normal microflora of the upper respiratory tract. The spectrum of pathogens of bacterial pneumonia is determined by the form of the disease. Community-acquired form is most often caused by pneumococci, hemophilic bacillus. Nosocomial bacterial pneumonia is usually initiated by multi-resistant strains of Staphylococcus aureus, Pseudomonas aeruginosa, Friedlander’s bacillus, Enterobacteria, Hemophilus bacillus, anaerobes. The causative agents of ventilator-associated pneumonia, which occurs when using a ventilator, in the early stages (48-96 hours) are the inhabitants of the microflora of the oral cavity, in the late (> 96 hours) – nosocomial strains.
In other bacterial diseases (anthrax, gonorrhea, salmonellosis, tularemia, typhoid fever, whooping cough), representatives of a specific microflora can serve as pathogens of pneumonia. In an immunodeficient state, bacterial agents often act as pneumococci, legionella and hemophilic bacillus.
Pathogenic microorganisms can enter the lung tissue by direct, airborne and hematogenic pathways. In patients with neurological symptoms and impaired consciousness, aspiration of secretions of the oral cavity and nasopharynx contaminated with bacteria is often observed. Hematogenic dissemination of the causative agent of bacterial pneumonia occurs with blood flow from the extrapulmonary focus (with infectious endocarditis, pharyngeal abscess). The infection can enter the lungs with chest wounds, tracheal intubation, from surrounding tissues with a breakthrough of a subdiaphragmatic abscess, etc.
In the pathogenesis of bacterial pneumonia, not only virulence and the mechanism of penetration of the pathogen, but also the level of local and general immunity is decisive. Predispose to the development of bacterial pneumonia:
- smoking, alcohol consumption
- frequent stress, fatigue
- old age
- air pollution.
reduced immune protection. It occurs with concomitant pathology: congestive heart failure, congenital defects of the bronchopulmonary system, COPD, chronic ENT infection, immunodeficiency, severe and long-term diseases; due to surgical intervention and prolonged immobilization.
The classification of nosological forms of the disease is based on the types of infectious pathogens, according to which pneumococcal, staphylococcal, streptococcal, meningococcal pneumonia are distinguished, as well as pneumonia caused by hemophilic bacillus, Klebsiella, E. coli, Pseudomonas aeruginosa, legionella, etc. According to the clinical course, bacterial pneumonia is isolated:
- focal (bronchopneumonia). Inflammatory changes affect individual areas of lung tissue and adjacent bronchi.
- lobar (lobar, large). The parenchyma of the whole lobe of the lung is affected.
The lower parts of the lungs are more often affected. There may be unilateral and bilateral bacterial pneumonia, with simultaneous damage to the pleura, pleuropneumonia develops.
According to clinical and pathogenetic criteria, bacterial pneumonia can have the character of community-acquired (outpatient) or nosocomial (hospital, nosocomial) infection with the development of symptoms 48-72 hours after the patient is admitted to the hospital. Bacterial pneumonia can have a mild, moderate, severe and prolonged course.
Bacterial pneumonia symptoms
Clinical manifestations and severity of bacterial pneumonia are determined by the type of pathogen, the volume of the lesion, the age and state of health of the patient. In a typical case of bacterial pneumonia, there is a sudden remitting fever, a productive cough with mucopurulent or rusty sputum, sometimes pleural chest pains. Patients are concerned about severe weakness, severe malaise, headache, shortness of breath, myalgia and arthralgia, loss of appetite. Sinus tachycardia, arrhythmia, arterial hypotension are often detected. Signs of respiratory, cardiac and renal failure may develop.
Staphylococcal pneumonia is characterized by a violent onset, a jump in temperature to 40 ° C with recurrent chills, a general serious condition associated with the destruction of the lungs, the appearance of foci of necrosis, cavities, abscessing of lung tissue. Friedlander’s pneumonia resembles croup pneumonia, has a prolonged course and is accompanied by fever (39-40 ° C), persistent cough, release of viscous brown sputum with an unpleasant odor, general intoxication, rapid development of extensive necrosis of lung tissue, single abscesses, pleurisy, lung infarction, septic complications. Severe pneumonia caused by Pseudomonas aeruginosa is characterized by a high mortality rate. With pneumococcal pneumonia, necrosis and abscess rarely develop.
Atypical forms of pneumonia occur when the lungs are infected with oral anaerobes, legionella. Their feature is the gradual development of symptoms, the dominance of extrapulmonary manifestations. For example, legionella pneumonia is accompanied by neurological manifestations, liver dysfunction, diarrhea. In the elderly, bacterial pneumonia is characterized by a prolonged course with prolonged subfebrility, a marked deterioration in well-being, severe shortness of breath, exacerbation of concomitant diseases, central nervous system dysfunction.
Bacterial pneumonia is characterized by damage to the respiratory tract with inflammatory infiltration of the lung parenchyma; pleural irritation syndrome and pleural effusion. It is possible to form foci of pulmonary tissue necrosis with the formation of a cavity, complicated by necrotic pneumonia, lung abscess. Also, complications of bacterial pneumonia can be pleural empyema, lung gangrene, with severe DN – respiratory distress syndrome. Generalization of bacterial infection is dangerous by the development of glomerulonephritis, meningitis, infectious and toxic shock, sepsis.
When examining a patient with bacterial pneumonia, pallor, cyanosis, heavy breathing is noted; palpation – increased vocal tremor from the lesion; percussion – shortening and dulling of the pulmonary sound; auscultation – increased bronchophony, hard or bronchial breathing, moist small-bubbly wheezing and pleural friction noise. Inflammation syndrome in bacterial pneumonia is confirmed by leukocytosis with a shift of the formula to the left, lymphopenia, moderate or significant increase in ESR, the appearance of C-reactive protein.
Lung x-ray in direct and lateral projections determines the presence, localization and extent of areas of inflammation and destruction of lung tissue, the presence of pleural effusion. Microscopy, as well as culture seeding of sputum and bronchial flushing waters helps to establish a potential causative agent of bacterial pneumonia. Additionally, blood is seeded for sterility, analysis of pleural effusion, ELISA. In case of dyspnea and chronic pulmonary pathology, PDV is studied, in case of severe complicated course of bacterial pneumonia, the gas composition of arterial blood is studied to assess the level of hypoxemia and hypercapnia, saturation of Hb with oxygen.
Spiral CT and MRI of the lungs are used to differentiate the diagnosis. When diagnosing bacterial pneumonia, it is necessary to exclude infiltrative tuberculosis, lung cancer, lung infarction, eosinophilic infiltrate, congestive heart failure, lung atelectasis.
Bacterial pneumonia treatment
Treatment of bacterial pneumonia, depending on the severity, is carried out on an outpatient basis or in a hospital, if necessary in the IT department. During the feverish period, bed rest, copious drinking, and easily digestible nutrition are recommended.
Etiotropic antimicrobial therapy is prescribed empirically with correction after identification of the pathogen and obtaining an antibioticogram. In bacterial pneumonia, aminopenicillins, macrolides, cephalosporins are used in the form of monotherapy or a combination of several antimicrobial drugs. In case of mild community-acquired pneumonia, oral and intramuscular forms of drugs are prescribed, in severe cases, intravenous administration is advisable; the duration of treatment is 10-14 days.
With pneumonia caused by staphylococci, enterobacteria and legionella, a longer course of antibiotic therapy is required, amounting to 14-21 days. In aspiration and hospital bacterial pneumonia, fluoroquinolones, carbapenems, combinations with aminoglycosides, lincosamides and metronidazole are additionally used.
In complicated cases, detoxification and immunotherapy, correction of microcirculatory disorders and dysproteinemia, oxygen therapy are performed. Antipyretics, analgesics, glucocorticoids, cardiac medications may be prescribed. Patients with bronchoobstructive pathology are shown aerosol therapy with bronchodilators and mucolytics.
When abscessing, sanitization bronchoscopy is performed using solutions of antiseptics, antibiotics, mucolytics. Breathing exercises, massage, physiotherapy are recommended. The observation of a therapist and a pulmonologist, sanatorium-resort treatment is shown.
Prognosis and prevention
The prognosis of bacterial pneumonia is due to the severity of the process, the adequacy of antibiotic therapy. Mortality in bacterial pneumonia reaches 9% (in nosocomial form – 20%, in elderly patients – 30%, in complicated cases – up to 50%). Prevention consists in the rehabilitation of purulent foci of ENT organs, compliance with the rules and principles of ventilation, and increased immune reactivity. An important component is adequate antibiotic therapy of various infections.