Бронхоэктазы и другие заболевания легких: причины, диагностика и лечение.

Disease of the lungs
Bronchiectasis may result from a number of infectious and acquired causes, including measles, pneumonia, tuberculosis, immune system problems, as well as the genetic disorder cystic fibrosis. Cystic fibrosis eventually results in severe bronchiectasis in nearly all cases. The cause in 10–50% of those without cystic fibrosis is unknown. The diagnosis is suspected based on symptoms and confirmed using computed tomography. Cultures of the mucus produced may be useful to determine treatment in those who have acute worsening and at least once a year. Antibiotics, such as erythromycin, may also be used to prevent worsening of disease. Airway clearance techniques, a type of physical therapy, are also recommended. Medications to dilate the airways and inhaled steroids may be used during sudden worsening, but there are no studies to determine effectiveness. There are also no studies on the use of inhaled steroids in children. The disease affects between 1 per 1000 and 1 per 250,000 adults. The disease is more common in women and increases as people age. Atelectasis occur when one or more segments of the lungs collapse or do not inflate properly. Other pulmonary complications include lung abscess and empyema. Cardiovascular complications include cor pulmonale, in which there is enlargement and failure of the right side of the heart as a result of disease of the lungs.

Cystic fibrosis is the most common life threatening autosomal recessive disease in the United States and Europe. It is a genetic disorder that affects the lungs, but also the pancreas, liver, kidneys, and intestine. It is caused by mutations in the CFTR protein, a chloride channel expressed in epithelial cells. In later stages, changes to the structure of the lung, such as bronchiectasis, occur.

An airway obstruction can be caused by either an intraluminal mass such as a tumor or a foreign body. The presence of an airway obstruction leads to a cycle of inflammation. In adults, foreign body aspiration is often associated with an altered state of consciousness. The foreign body is often unchewed food, or part of a tooth or crown. Bronchiectasis that results from foreign body aspiration generally occurs in the right lung in the lower lobe or posterior segments of the upper lobe.

A range of bacterial, mycobacterial, and viral lung infections are associated with the development of bronchiectasis. Bacterial infections commonly associated with bronchiectasis include P. aeruginosa, H. influenzae, and S. pneumoniae. Severe viral infections in childhood can also lead to bronchiectasis through a similar mechanism. Nontuberculous mycobacteria infections such as Mycobacterium avium complex are found to be a cause in some patients. Recent studies have also shown Nocardia infections to been implicated in bronchiectasis.

Impairments in host defenses that lead to bronchiectasis may be congenital, such as with primary ciliary dyskinesia, or acquired, such as with the prolonged use of immunosuppressive drugs. Additionally, these impairments may be localized to the lungs, or systemic throughout the body. In these states of immunodeficiency, there is a weakened or absent immune system response to severe infections that repeatedly affect the lung and eventually result in bronchial wall injury. HIV/AIDS is an example of an acquired immunodeficiency that can lead to the development of bronchiectasis.

Allergic bronchopulmonary aspergillosis (ABPA) is an inflammatory disease caused by hypersensitivity to the fungus Aspergillus fumigatus. It is suspected in patients with a long history of asthma and symptoms of bronchiectasis such as a productive, mucopurulent cough. Imaging often shows peripheral and central airway bronchiectasis, which is unusual in patients with bronchiectasis caused by other disorders.

Several autoimmune diseases have been associated with bronchiectasis. Specifically, individuals with rheumatoid arthritis and Sjögren syndrome have increased rates of bronchiectasis. In these diseases, the symptoms of bronchiectasis usually presents later in the disease course. Other autoimmune diseases such as ulcerative colitis and Crohn's disease also have an association with bronchiectasis. Additionally, graft versus host disease in patients who have undergone stem cell transplantation can lead to bronchiectasis as well. chronic pulmonary aspiration of stomach acid from esophageal reflux, or a hiatal hernia. A common genetic cause is cystic fibrosis, which affects chloride ion transport. When situs inversus is accompanied by chronic sinusitis and bronchiectasis, this is known as Kartagener's syndrome. Other rare genetic causes include Young's syndrome and Williams Campbell syndrome. Tracheobronchomegaly, or Mournier Kuhn syndrome is a rare condition characterized by significant tracheobronchial dilation and recurrent lower respiratory tract infections. Individuals with alpha 1 antitrypsin deficiency have been found to be particularly susceptible to bronchiectasis, due to the loss of inhibition to enzyme elastase which cleaves elastin. This decreases the ability of the alveoli to return to normal shape during expiration.

A causal role for tobacco smoke in bronchiectasis has not been demonstrated.

The development of bronchiectasis requires two factors: an initial injury to the lung (such as from infection, auto immune destruction of lung tissue, or other destruction of lung tissue (as seen in gastroesophageal reflux disease or aspiration syndromes)) which leads to impaired mucociliary clearance, obstruction, or a defect in host defense. Disordered neutrophil function is believed to play a role in the pathogenesis of bronchiectasis. Neutrophil extracellular traps (NETs), which are extracellular fibers secreted by neutrophils that are used to trap and destroy pathogens, are hyperactive in bronchiectasis. Increased NET activity is associated with more severe bronchiectasis.

The goals of a diagnostic evaluation for bronchiectasis are radiographic confirmation of the diagnosis, identification of potential treatable causes, and functional assessment of the patient. A comprehensive evaluation consists of radiographic imaging, laboratory testing, and lung function testing. Laboratory tests that are commonly part of the initial evaluation include a complete blood count, sputum cultures for bacteria, mycobacteria, and fungi, testing for cystic fibrosis, and immunoglobulin levels. There are three types bronchiectasis that can be seen on CT scan, namely cylindrical, varicose, and cystic bronchiectasis.

In preventing bronchiectasis, it is necessary to prevent the lung infections and lung damage that can cause it. Treatments to slow down the progression of this chronic disease include keeping bronchial airways clear and secretions weakened through various forms of airway clearance. Aggressively treating bronchial infections with antibiotics to prevent the destructive cycle of infection, damage to bronchi and bronchioles, and more infection is also standard treatment. Regular vaccination against pneumonia, influenza, and pertussis are generally advised. A healthy body mass index and regular doctor visits may have beneficial effects on the prevention of progressing bronchiectasis. The presence of hypoxemia, hypercapnia, dyspnea level and radiographic extent can greatly affect the mortality rate from this disease.

A comprehensive approach to the management of bronchiectasis is recommended. It is important to establish whether an underlying modifiable cause, such as immunoglobulin deficiency or alpha 1 antitrypsin deficiency is present.

The goal of airway clearance therapy is to loosen secretions and interrupt the cycle of inflammation and infection. Airway clearance techniques improve difficulty breathing, cough, and help patients cough up phlegm and mucus plugs. Airway clearance usually uses an inhaled agent (hypertonic saline) with chest physiotherapy, such as high frequency chest wall oscillation. The active cycle of breathing technique (ACBT), which can be employed with or without a flutter device, is beneficial in treating those with bronchiectasis. Mucolytic agents such as dornase alfa are not recommended for individuals with non CF bronchiectasis. The impact of adverse effects of macrolides such as gastrointestinal symptoms, hepatotoxicity, and increased antimicrobial resistance needs ongoing review and study. One commonly used therapy is beclometasone dipropionate.

Antibiotics are used in bronchiectasis to eradicate P. aeruginosa or MRSA, to suppress the burden of chronic bacterial colonization, and to treat exacerbations. Options for inhaled antibiotics include aerosolized tobramycin, inhaled ciprofloxacin, aerosolized aztreonam, and aerosolized colistin. To combat this and prolong the amount of time the antibiotic spends in the lung tissue, current study trials have moved to develop inhalable nanostructured lipid carriers for the antibiotics.

The primary role of surgery in the management of bronchiectasis is in localized disease to remove segments of the lung or to control massive hemoptysis. Surgical case series have shown low operative mortality rate (less than 2%) and improvement of symptoms in the majority of patients selected to receive surgery. However, no randomized clinical trials have been performed evaluating the efficacy of surgery in bronchiectasis.

The prevalence and incidence of bronchiectasis is unclear as the symptoms are variable. The disease affects between 1 per 1000 and 1 per 250,000 adults. A similar prevalence rate of bronchiectasis has been reported in other countries including China, Germany, the United Kingdom, Spain and Singapore. Specifically, children of the indigenous populations of Australia, Alaska, Canada and New Zealand have significantly higher rates than other populations. Overall, a shortage of data exists concerning the epidemiology of bronchiectasis in Asia, Africa, and South America. This large increase in the diagnosis of bronchiectasis may be due to increased recognition of the disease (including more widespread use of CT scans) or it may be due to an increase in the underlying causes of bronchiectasis. The disease was researched in greater detail by Sir William Osler, one of the four founding professors of Johns Hopkins Hospital, in the late 1800s. It is suspected that Osler himself died of complications from undiagnosed bronchiectasis. His biographies mention that he had frequent severe chest infections for many years. The term "bronchiectasis" comes from the Greek words bronkhia (meaning "airway") and ektasis (meaning "widening").

Judith Durham of the Australian band The Seekers died of bronchiectasis on August 5, 2022, at the age of 79.