Criteria of bronchiectasis

Pathophysiology and Pathogenesis.

In the developed world, cystic fibrosis is the most common cause of clinically significant bronchiectasis. Other conditions associated with bronchiectasis include ciliary dyskinesia, immune deficiency syndromes, and infection, especially pertussis, measles, and tuberculosis. Bronchiectasis can also be congenital. Williams-Campbell syndrome, in which there is an absence of annular bronchial cartilage, and Marnier-Kuhn syndrome (congenital tracheobronchomegaly), in which there is a connective tissue disorder, are two such examples. Other disease entities associated with bronchiectasis include right middle lobe syndrome (chronic extrinsic compression of right middle lobe bronchus by hilar lymph nodes) and yellow nail syndrome (pleural effusion, lymphedema, discolored nails).

In general, three basic mechanisms are involved in the pathogenesis of bronchiectasis. Obstruction can occur because of tumor, foreign body, impacted mucus caused by poor mucociliary clearance, external compression, bronchial webs, and atresia. Infections due to Bordetella pertussis, measles, rubella, togavirus, respiratory syncytial virus, and Mycobacterium tuberculosis induce chronic inflammation, progressive bronchial wall damage, and dilatation. Chronic inflammation, similarly, contributes to the mechanism by which obstruction leads to bronchiectasis. The mechanism by which bronchiectasis occurs in congenital forms is likely related to abnormal cartilage formation, as described earlier. The common thread in the pathogenesis of bronchiectasis is difficulty clearing secretions and recurrent infections.

Bronchiectasis can present in any combination of three pathologic forms. In cylindrical bronchiectasis the bronchial outlines are regular but there is diffuse dilatation of the bronchial unit. The bronchial lumen ends abruptly because of mucus plugging. In varicose bronchiectasis the degree of dilatation is greater and local constrictions cause an irregularity of outline resembling varicose veins. There may also be small sacculations. In saccular (cystic) bronchiectasis, bronchial dilatation progresses and results in ballooning of bronchi that end in fluid- or mucus-filled sacs. This is the most severe form of bronchiectasis.

Classification:

Forms of disease: slight, moderate or severe.

Periods of disease: relapse, remission.

Localization - one-sided, two-sided, restricted (segment, lobe) and spread, with indication of localization and type of endobronchitis.

Types of bronchiectasis: saccular (cyst-like), cylindrical, mixed.

Criteria of bronchiectasis

I. Anamnestic data:

- frequent repeated pneumonias with the same localization of lesion with lingering course, which begin at early childhood and infancy; severe pneumonias with lung destruction in the past.

II. Clinical:

- permanent productive cough, increasing during exacerbation, with production of mucopurulent sputum, more often in morning. Younger children may swallow the sputum. Hemoptysis is seen with some frequency;

- Fever can occur with infectious exacerbations;

- syndrome of chronic intoxication: pallor, grey skin, quick fatiguability, bad appetite, worsening of feeling. Anorexia and poor weight gain may occur as time passes;

- syndrome of chronic heart-pulmonary failure: cyanosis of naso-labial triangle and acrocyanosis; dyspnea and tachycardia after physical exertion (pulmonary function studies may demonstrate an obstructive, restrictive, or mixed pattern), clubbed fingers, curvature of the nails in their long axis (like "watch glasses");

- thorax deformation: asymmetry of the thorax; retractionor protrusion of separate parts. May be lag of one part of the thorax in the time of breathing;

- physical finding are characterized as stable:

a) on percussion - shortening of resonance or tympanictint above the lesion zone;

b) on auscultation - changing of breathing depending on the expression of process (harsh, bronchial sometimes amphoral, may be weakened ). Stable various moist and dry rales.

///. Instrumental:

- X-ray: on X-ray film made in remission there is a strengthened lung figure, thickening of bronchi walls of one or several segments, diminishing of separate lung segments (pneumosclerosis). Typical findings may include increase in size and loss of definition of bronchovascular markings, crowding of bronchi, and loss of lung volume. In more severe forms, cystic spaces, occasionally with air-fluid levels and honeycombing, may occur. Compensatory overinflation of unaffected lung may be seen.

- Bronchoscopy: bronchial deformation, saccular or cylindrical bronchiectasis, endobronchitis of different type (catarrhal, purulent etc.).

- Bronchography: bronchiectasis of various forms (cylindrical, varicose, cystic or mixed). Today, bronchography may still be used before surgery for lung biopsy or resection to provide better localization.

- CT scanning: Thin-section high-resolution CT scanning has replaced bronchography as the gold standard, because it has equal or better sensitivity and specificity and is less invasive. CT provides further information on disease location, presence of mediastinal lesions, and the extent of segmental involvement. The addition of radiolabeled aerosol inhalation to CT scanning can provide further information. The CT findings in patients with bronchiectasis typically include cylindrical (?tram lines,? ?signet ring appearance?), varicose (bronchi with ?beaded contour?), cystic (cysts in ?strings and clusters?), or mixed forms.

- Spirography: decreasing of reserve ability of external breathing, stable respiratory insufficiency.

- Pneumotachometry: disturbances of bronchial condition permeability.

IV. Laboratory findings:

1) WBC - inflammatory changes are present in relapse and absent on remission.

2) Immunological findings:

decreasing of secretory immunoglobulin A and G in bronchial content;

- decreasing of serum immunoglobulin A and G.

Differential diagnosis is provided with recurrent bronchitis; repeated, lingering pneumonias, tuberculosis of the lungs.

Treatment.

The initial therapy for patients with bronchiectasis is medical and aims at decreasing airway obstruction and controlling infection. Chest physiotherapy (postural drainage), antibiotics, and bronchodilators are essential. It is not unusual that 2?4 wk of parenteral antibiotics are necessary to adequately manage acute exacerbations. Antibiotic choice is dictated by the identification and sensitivity of organisms found on deep throat, sputum, or bronchoalveolar fluid cultures. More often must be used amoxicillin/clavulanate, parenteral cefalosporins of II-IV generation of aminoglycosides. Chronic prophylactic oral antibiotics may be beneficial (macrolide antibiotic such as azithromycin is prefere). Any underlying disorder (e.g., immunodeficiency, aspiration) that may be contributing must also be addressed. When localized bronchiectasis becomes more severe or resistant to medical management, segmental or lobar resection may be warranted. Lung transplantation has also been performed in patients with bronchiectasis.

Prognosis.

Overall, the prognosis for patients with bronchiectasis has improved considerably over the past few decades. Earlier recognition or prevention of predisposing conditions, more powerful and wide-spectrum antibiotics, and improved surgical outcomes are likely reasons.

Date: 2016-06-13; view: 5