Tuberculosis: an overview of information

Tuberculosis is a disease that occurs when the microorganisms of the genus Mycobacteria are infected with a mycobacterium complex - Mycobacterium tuberculosis complex. The composition of this complex includes several species of mycobacteria Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium africanum (the first two species are the most pathogenic microorganisms).

One bacterial excretor per year can infect an average of about 10 people. The likelihood of infection increases in the following situations:

• when in contact with a sick tuberculosis with a massive bacterial release;
• with prolonged contact with a bacteriovirus (residence in a family, being in a closed institution, professional contact, etc.);
• at close contact with bakteriovydelitelem (being with the patient in the same room, in a closed collective).

After infection with mycobacteria, the development of a clinically pronounced disease is possible. The probability of a disease in a healthy infected person throughout life is about 10%. Development of tuberculosis primarily depends on the state of the human immune system (endogenous factors), as well as from repeated contact with mycobacteria tuberculosis (exogenous superinfection). The likelihood of the disease increases in the following situations:

• in the first years after infection:
• during puberty;
• with repeated infection with mycobacteria tuberculosis:
• in the presence of HIV infection (the probability increases to 8-10% per year);
• in the presence of concomitant diseases (diabetes mellitus, etc.):
• during the therapy with glucocorticoids and immunosuppressants.

Tuberculosis is not only a medical-biological, but also a social problem. Great importance in the development of the disease has psychological comfort, socio-political stability, material standard of living, sanitary literacy. General population culture, housing conditions, availability of qualified medical care, etc.

The role of primary infection, endogenous reactivation and exogenous superinfection

Primary tuberculosis infection occurs during primary infection of a person. As a rule, this causes adequate specific immunity and does not lead to the development of the disease.

With exogenous superinfection, repeated penetration of mycobacteria of tuberculosis into the body and their multiplication are possible.

With close and prolonged contact with the bacteriovirus, the mycobacterium tuberculosis is repeatedly and in large quantities enters the body. In the absence of specific immunity, early massive superinfection (or constant re-infection) often causes the development of acute progressive generalized tuberculosis.

Even in the presence of specific immunity, developed after the previous primary infection, late superinfection can also contribute to the development of the disease. In addition, exogenous superinfection can exacerbate and progress the process in a patient with tuberculosis.

Endogenous reactivation of tuberculosis arises from retained activity or aggravated primary or secondary foci in organs. Possible causes - a decrease in immunity due to the presence of background or exacerbation of concomitant diseases. HIV-infection, stressful situations, malnutrition, changes in living conditions, etc. Endogenous reactivation is possible in persons of the following categories:

• an infected person who has never had any signs of active tuberculosis:
• in a person who has transferred active tuberculosis and a clinically cured person (once infected, a person retains mycobacterium tuberculosis for life in the body, that is, a biological cure is impossible);
• in a patient with a diminishing activity of the tuberculosis process.

The likelihood of endogenous reactivation in infected individuals allows tuberculosis to maintain a reservoir of infection even in the clinical cure of all contagious and non-contagious patients.

Tuberculosis: epidemiology

Worldwide, according to WHO, tuberculosis affects nine million people every year, and more than two million people die from it, with 95% of TB patients living in developing countries. In the developed countries of Europe, the incidence of tuberculosis over the past decade has increased by 20-40% (due to immigrants), while among the indigenous population, the prevalence of this disease has been declining.

In Russia at the beginning of the 20th century, the death rate from tuberculosis was roughly on par with that of European countries. Subsequently, a gradual decrease in mortality was observed. However, during the last century four periods characterized by a sharp increase in mortality and worsening of the epidemic situation marked the First World War, the Civil War, industrialization (30s of the XX century), the Great Patriotic War. The fourth period began with the collapse of the USSR and developed against the background of the economic crisis. From 1991 to 2000, the incidence of tuberculosis increased from 34 to 85.2 cases per 100,000 people (in the United States, this figure is 7). During this period, the mortality rate also increased from 7.4 to 20.1 cases per 100,000 people. One of the reasons for the sharp deterioration in the epidemic situation in the country is considered the migration of the population from the republics of the former USSR. The prevalence of tuberculosis among migrants is 6-20 times higher than that among the indigenous population. Currently, the value of the death rate from tuberculosis in the developed countries of Europe is 10-20 times lower than in Russia, 40 times in Germany, 50 times in the United States.

Symptoms of tuberculosis

It should be borne in mind that the bulk of tuberculosis specialists under intensive tuberculosis therapy are understood as intensive chemotherapy regimens for the disease, for example, treatment with not three but five or more antituberculous drugs at the same time. At present, there is no clear definition of the concept of intensive care for tuberculosis. According to a widely spread opinion, the anesthesiologist-resuscitator should first of all correct and treat such complications of tuberculosis as respiratory and heart failure, pulmonary hemorrhage, PON, and also to learn the methods of intensive preoperative preparation and methods of monitoring the patient suffering from tuberculosis in during the early postoperative period. The appointment of chemotherapeutic drugs in our country is traditionally produced by the phthisiatrist.

Clinical forms of pulmonary tuberculosis

There are several forms of tuberculosis, they are characterized by various complications, so the doctor of the intensive care unit must have minimal information about the variety of clinical forms of tuberculosis. However, traditionally, the treatment of complications is performed by anesthetists and resuscitators. It should be noted that the description of some clinical forms is reduced (due to their low significance for the intensive therapist).

[1], [2], [3], [4], [5], [6], [7]

Disseminated tuberculosis of the lungs

For this form of the disease is characterized by the formation of multiple tuberculosis foci of productive inflammation in the lungs, formed as a result of hematogenous, lymphohematogenic or lymphogenous dissemination of mycobacterium tuberculosis. With hematogenous dissemination, foci are found in both lungs. When performing inefficient (or inadequate) treatment, the disease becomes chronic disseminated pulmonary tuberculosis with subsequent development of sclerosis, massive fibrosis and emphysema.

[8], [9], [10], [11], [12], [13], [14], [15], [16], [17]

Focal pulmonary tuberculosis

Focal pulmonary tuberculosis is characterized by the appearance of a few foci with a size of 2-10 mm. A distinctive feature of this form of the disease is considered a small number of clinical symptoms. Focal tuberculosis is considered as a small form of tuberculosis. As a result of the treatment, the foci dissolve or turn into scars. When the old foci is exacerbated, they are noted for their calcification.

[18], [19], [20]

Infiltrative pulmonary tuberculosis

The formation of caseous foci, extending to segments (or lobes) of the lung, occurs with infiltrative tuberculosis. Often, the tendency of this form of the disease to acute and progressive course is noted. With adequate treatment, infiltrates can regress with restoration of the structure of the lung tissue. Sometimes, despite the proper treatment, there is a formation of connective tissue seals at the site of infiltrates.

Caseous pneumonia

Caseous pneumonia is considered the most severe form of tuberculosis. This disease is characterized by acute, progressive course and high lethality, reaching 100% in the absence of treatment. In the lungs, zones of caseous necrosis with a lobular or multiple lobular lesion are determined. Distinguish lobar and lobular caseous pneumonia. With effective treatment on the spot of pneumonia, there is formation of fibro-cavernous pulmonary tuberculosis.

[21], [22], [23], [24], [25]

Tuberculosis of the lungs

Tuberculoma of the lung is a capsular caseous focus with a diameter of more than 1 cm. For this form of the disease is characterized by asymptomatic (or malosimptomnoe) chronic course. Among all patients with rounded lung lesions detected, tuberculoma is diagnosed slightly less frequently than peripheral cancer. This form of the disease is not considered the cause of death of patients from tuberculosis.

Cavernous tuberculosis

Cavernous pulmonary tuberculosis is detected by the presence of an air cavity in the lung, with inflammatory and fibrotic wall changes absent. Clinical symptoms are usually poorly expressed.

[26], [27], [28], [29],

Fibrous-cavernous tuberculosis

Fibrous-cavernous tuberculosis is characterized by the presence in the lungs of chambers with pronounced fibrosis not only of the wall, but also surrounding tissues, as well as the formation of numerous foci of seeding. For fibro-cavernous tuberculosis, a typically prolonged (with flares or continuous) progressing course. This clinical form of the disease (and complications) is one of the main causes of death of patients suffering from pulmonary tuberculosis.

[30], [31], [32], [33]

Cirrhotic tuberculosis of the lungs

With cirrhotic pulmonary tuberculosis, massive fibrosis of the lungs and pleura and the presence of active and healing tuberculosis foci are noted. Cirrhosis is the result of deforming sclerosis of the lungs and pleura. Pneumogenic cirrhosis, as a rule, arises as an outcome of fibro-cavernous tuberculosis. Patients suffering from this clinical form of the disease usually die from pulmonary-cardiac failure, pulmonary hemorrhage and amyloidosis of internal organs.

[34], [35], [36], [37], [38], [39]

Tuberculous pleurisy and pleural empyema

Tuberculous pleurisy - inflammation of the pleura with subsequent exudation into the pleural cavity. It can occur as a complication of pulmonary tuberculosis or tuberculosis of other organs. The disease includes three clinical forms of fibrinous (dry) pleurisy, exudative pleurisy and tuberculosis empyema. Sometimes tuberculous pleurisy proceeds as an independent disease (without the symptoms of tuberculosis of other organs), in which case pleurisy is the first sign of tuberculosis infection. With pleural tuberculosis, serous fibrinous or hemorrhagic pleural effusion is detected. In destructive forms of pulmonary tuberculosis, the cavity perforates into the pleural cavity, where the contents of the cavity enter. Then, the pleural cavity becomes infected and, as a consequence, the empyema is formed. In patients with pleural empyema, pulmonary heart disease, respiratory failure, amyloidosis of internal organs are often diagnosed.

In developed countries, tubercular empyema is considered a casuistic form of the pleura. Most often this disease is registered in developing countries. So, one Chinese study was devoted to the analysis of pleural effusions and pleural empyema in patients (treated 175 cases), admitted to the ICU. As a result, only three patients (out of 175) were found to have tuberculosis mycobacteria when performing a microbiological study.

The listed diseases are far from a complete list of clinical forms of pulmonary tuberculosis. Sometimes diagnosed tuberculosis of bronchial tubes, trachea, larynx, tuberculous lymphadenitis and other conditions, much less often requiring professional intervention of an intensive therapist.

Central Nervous System Tuberculosis

[40], [41], [42], [43], [44]

Tuberculous meningitis

Cases of tuberculous meningitis in the developed countries are rarely recorded. For example, in the US, no more than 300-400 cases are recorded per year. In the absence of adequate treatment, most patients die in 3-8 weeks. Against the background of treatment, lethality is 7-65%. Tuberculous meningitis is diagnosed in both children and adults. As a rule, the disease occurs in patients with pulmonary tuberculosis or tuberculosis of other organs. However, there are mentions of meningitis as the only clinical manifestation of the tuberculosis process. Often the inflammatory process spreads from the membranes not only to the brain substance (meningoencephalitis), but also to the substance of the spinal cord (the spinal form of meningitis).

Subfebrile temperature and general malaise are the first symptoms of tuberculous meningitis. Then, hyperthermia (up to 38-39 ° C), an increase in the intensity of headaches (due to hydrocephalus formation), vomiting is noted. Some patients develop meningeal symptoms. Sometimes the disease begins acutely - with a high fever and the onset of meningeal symptoms. Such a clinical picture, as a rule, is observed in children. In the absence of adequate treatment, sopor and coma occur, after which patients usually die.

When performing a blood test, leukocytosis with a stab-shift shift is noted, sometimes the number of white blood cells is normal. Characterized by lymphopenia and increased ESR.

The diagnosis of tuberculous meningitis is of great importance in the study of CSF. Detect cytosis (increased content of cellular elements) with a predominance of lymphocytes (100-500 cells / μl), increasing the protein content to 6-10 g / l (due to coarsely dispersed fractions). A decrease in the amount of chlorides and glucose is recorded. In case of tuberculous meningitis, seizures of fibrin (in the form of a mesh or a herringbone) are noted in a CSF confiscated in a test tube after 24 hours. If spinal puncture was performed prior to the initiation of a specific therapy, then the mycobacterium tuberculosis is sometimes found in the fluid (in less than 20% of cases). Immunoenzymatic analysis of CSF allows detection of anti-tuberculosis antibodies (in 90% of cases).

Tuberculous meningitis requires prolonged treatment for 9-12 months. In addition to specific anti-tuberculosis therapy, glucocorticoid drugs are prescribed. It is believed that taking glucocorticoids for a month and then gradually reducing the dose of drugs can reduce the likelihood of developing distant neurological complications and their number. Particularly good effect of these drugs is registered in children. If there are signs of hydrocephalus, dehydration therapy is prescribed, lumbar punctures are made to remove 10-20 ml of CSF. In severe intracranial hypertension, it is recommended to perform surgical decompression. Neurological complications occur in 50% of surviving patients.

Brain Tuberculosis

Tuberculosis of the brain is most often diagnosed in children and young patients (up to 20 years). The disease develops in patients with tuberculosis of various organs or with tuberculosis of the intrathoracic lymph nodes, but in some patients the brain tuberculoma arises as the only clinical form. The localization of tuberculosis is diverse - they are found in any area of the brain. For this disease is characterized by a wavy course with remissions of Tuberculoma occurs against a background of long subfebrile condition. Mark headache, nausea and vomiting, often determine meningeal symptoms. Severity and the presence of neurologic symptoms depend on the localization of tuberculoma

On conventional radiographs, tuberculoma is determined, mainly, by the deposition of calcium salts in it. Therefore, the main method of diagnosing tuberculosis is considered computer and magnetic resonance imaging.

Treatment - only surgical. Surgical intervention is performed against the background of taking antituberculous drugs throughout the preoperative and postoperative period.

[45], [46], [47], [48], [49], [50], [51], [52]

Cardiovascular tuberculosis

[53], [54], [55], [56], [57], [58]

Tuberculous pericarditis

In countries with a low incidence of tuberculosis, this clinical form is considered a serious, but rare, complication that occurs more often in the elderly and in patients with HIV infection. In Russia, tubercular pericarditis is recorded quite often according to pathoanatomical data, 1.1-15.8% of patients who died from pulmonary tuberculosis find the involvement of the heart in the pathological process. Sometimes pericarditis is the first clinical sign of tuberculosis. However, as a rule, pericarditis is diagnosed in combination with tuberculosis of other organs. Often noted defeat pleura and peritoneum (poliserosit).

Characteristic subacute onset of the disease, masked by clinical symptoms of tuberculosis with fever, shortness of breath and weight loss. In some cases, the disease debuts sharply and is accompanied by pain behind the sternum and pericardial friction noise. Almost always there is a pericardial effusion, in severe cases a cardiac tamponade develops. When examining exudate (mainly hemorrhagic nature), it contains a large number of leukocytes and lymphocytes, and in 30% of cases - mycobacterium tuberculosis. A biopsy can establish a diagnosis of tuberculous pericarditis in 60% of cases.

To establish an accurate diagnosis, X-ray diagnostics, CT and ultrasound are of great importance.

The main method of treatment - chemotherapy, but sometimes resort to surgical intervention and puncture.

In addition to the pericardium, tuberculosis often involves involvement in the pathological process of the myocardium, endocardium, epicardium, aorta and coronary arteries.

Osteoarticular tuberculosis

Osteoarticular tuberculosis is a disease that affects all parts of the skeleton. The most frequent localizations are the spine, hip, knee, elbow and shoulder joints, as well as the bones of the hands and feet. Occurs as a result of lymphohematogenous spread of infection. The process can spread to surrounding bone and soft tissues and cause the development of abscesses and fistulas.

The main methods of treatment are specific chemotherapy and surgical interventions aimed at removing the focus of infection and restoring the functions of bones and joints.

Urologic Tuberculosis

As a result of hematogenous or lymphohematogenous spread of infection, kidneys, ureters or the bladder are affected. Tuberculosis of the kidneys (often combined with tuberculosis of other organs) is a sign of a generalized tuberculosis infection. When the renal tissue is destroyed, a cavern is formed, which is open in the pelvis. Around the cavern, new cavities of decay arise, followed by the formation of polycavernous tuberculosis. In the future, the process often extends to the pelvis, ureters, and bladder. Treatment - specific chemotherapy and surgical interventions.

Abdominal tuberculosis

For many decades, the disease was diagnosed quite rarely, so some experts refer abdominal tuberculosis (along with caseous pneumonia) to relict forms. However, in the last 10-15 years, a sharp increase in the prevalence of this pathology has been noted. In the first place, mesenteric lymph nodes and the formation of tuberculous mesidenitis occur. It is often recorded the spread of the process to other groups of lymph nodes of the abdominal cavity, as well as to the peritoneum, intestine and pelvic organs. In chronic forms, calcification of lymph nodes is often noted. As a rule, tuberculous peritonitis, sometimes arising as an independent disease, is a complication of generalized tuberculosis or tuberculosis of the abdominal organs. Tuberculosis of the intestine also sometimes develops as an independent disease, but it is mainly found in the progression of tuberculosis of intra-abdominal lymph nodes or other organs. Tuberculous ulcers of the intestine can cause perforation of its walls.

To establish the diagnosis, laparoscopy with a biopsy of sites suspicious of tuberculosis is of great importance.

Treatment - long (up to 12 months) chemotherapy. Operative treatment is usually performed in the development of such complications of abdominal tuberculosis, as intestinal obstruction, perforation of tuberculous ulcers.

[59], [60], [61], [62], [63], [64], [65], [66],

Other clinical forms of tuberculosis

Other clinical forms of the disease, for example tuberculosis of the genitals, skin, eyes, are of less importance for the intensive therapist.

Classification of tuberculosis

• Pulmonary tuberculosis
  • Disseminated tuberculosis of the lungs
  • Focal pulmonary tuberculosis
  • Infiltrative pulmonary tuberculosis
  • Caseous pneumonia
  • Tuberculoma of the lungs
  • Cavernous tuberculosis
  • Fibrous-cavernous tuberculosis
  • Cirrhotic tuberculosis of the lungs
  • Tuberculous pleurisy and pleural empyema
  • Tuberculosis of the bronchi
  • Tracheal tuberculosis
  • Laryngeal tuberculosis
  • Tuberculous lymphadenitis
• Central tuberculosis
  • Tuberculous meningitis
    • Tuberculous meningoencephalitis
    • Spinal form of tuberculous meningitis
  • Tuberculoma of the brain
• Cardiovascular tuberculosis
  • Tuberculous pericarditis
• Osteoarticular tuberculosis
• Urologic Tuberculosis
• Abdominal tuberculosis
  • Other clinical forms of tuberculosis
    • Tuberculosis of genital organs
    • Lupus
    • Tuberculosis of the eye

[67], [68], [69], [70], [71], [72], [73], [74],

Treatment of tuberculosis

The main method of treating tuberculosis of various localizations is considered chemotherapy. Its therapeutic effect is due to antibacterial action and is aimed at suppressing the reproduction of mycobacteria or their destruction (bacteriostatic and bactericidal effect). Rifampicin, streptomycin, isoniazid, pyrazinamide and ethambutol are the main antituberculous drugs.

Reserve drugs are used in the treatment of drug-resistant forms of tuberculosis. These include kanamycin, capreomycin, amikacin, cycloserine, fluoroquinolones, ethionamide, prothionamide, rifabutin, aminosalicylic acid (PASC). Some drugs (eg rifampicin, fluoroquinolones, ethambutol, cycloserine and prothionamide) have the same activity against intracellular and extracellular mycobacterial tuberculosis . Capreomycin and aminoglycosides have a less pronounced effect on mycobacteria localized within the cells. A relatively small bacteriostatic activity is possessed by pyrazinamide. However, the drug enhances the effect of many drugs, penetrates well into cells and produces a significant effect in the acidic environment of caseous disease.

The standard treatment regimen is the joint administration of rifampicin, isoniazid, pyrazinamide, and ethambutol (or streptomycin). In our country with a well-developed TB services traditionally the scheme, methods and duration of chemotherapy is determined by the phthisiatrist.

It is interesting to know that the first randomized trial in the world was conducted in phthisiology. In 1944, the United States received streptomycin. In 1947-1948 in the UK, the first study with the participation of patients with tuberculosis was performed. The control group consisted of patients who observed bed rest, the main group - patients who received streptomycin additionally. However, the study used an insufficient amount of the drug, and its effectiveness has not yet been conclusively proven. Because of the small amount of streptomycin, the study was ethically acceptable.

As studies have shown, the use of streptomycin in the treatment of pulmonary tuberculosis can reduce the lethality from 26.9% in the control group to 7.3% in the group of patients who used streptomycin. In fact, this statement can be considered the birthday of not only evidence-based medicine, but also modern chemotherapy for tuberculosis.