Chapter 312 - Bronchiectasis

Question 1

Bronchiectasis might occur in non-infectious diseases.

True or False?

Answer 1

True.

Question 2

Bronchiectasias are always an irreversible dilation of the airway.
True or False?

Answer 2

True.

Question 3

How can you classify bronchiectasis? Which one is the most common form?

Answer 3

“cylindrical or tubular (the most common form), varicose, or cystic.”

Question 4

Name one cause of focal bronchiectasis that can either obstruct the airway extrinsecally or intrinsecally.

Answer 4

Tumor.

Question 5

Give examples of intrinsic and extrinsic obstruction of the airway.

Answer 5

“Focal bronchiectasis refers to bronchiectatic changes in a localized area of the lung and can be a consequence of obstruction of the airway - either extrinsic (e.g., due to compression by adjacent lymphadenopathy or parenchymal tumor mass) or intrinsic (e.g., due to an airway tumor of aspirated foreign body, a scarred/stenotic airway, or bronchial atresia from congenital underdevelopment of the airway).”

Question 6

Which diagnostic tests are important in the workup of focal bronchiectasis?

Answer 6

“Chest imaging (chest x-ray and/or chest computed tomography); bronchoscopy.”

Question 7

What are the seven categories of diseases that might be responsible for diffuse bronchiectasis?

Answer 7

Infection, immunodeficiency, genetic autoimmune/rheumatologic, recurrent aspiration, miscellaneous and idiopathic.

Question 8

Kartagener’s syndrome is a miscellaneous cause of diffuse bronchiectasis.
True or False?

Answer 8

False.
It is a genetic cause.
(other genetic causes include cystic fibrosis and alpha1-antitrypsin deficiency)

Question 9

Name autoimmune/rheumatologic causes of bronchiectasis.

Answer 9

Rhematic arthrtitis, Sjogren’s syndrome, inflammatory bowel disease and bronchopulmonary aspergillosis.

Question 10

How frequent are idiopathic bronchiectasis?

Answer 10

25-50% of the patients.

Question 11

Name the conditions that affect predominantly the following portion of the lungs: (i) upper lungs; (ii) lower lungs; (iii) middle lungs; (iv) central airways.

Answer 11

(i) Cystic fibrosis and postradiation fibrosis.
(ii) Chronic recurrent aspiration, endstage fibrotic lung disease or recorrent immunodeficiency-associated infections.
(iii) MAC infection, dyskinetic/immotile cilia syndrome.
(iv) Allergic bronchopulmonary aspergillosis and cartilage deficiency syndromes (Mounier-Kuhn and Williams-Campbell).

Question 12

Which lobes would you expect to be affected in esclerodermia?

Answer 12

If the esclerodermia is assocaited with esophageal dismotily and consequent recurrent aspiration, the lower lobes would be predominantly involved.

Question 13

What is the typical patient with bronchiectasis due to mycobacterium avium-intracellulare complex infection?

Answer 13

Nonsmoking women >50 years of age.

Question 14

When is it that tuberculosis might lead to diffuse bronchiectasias?

Answer 14

Especially in reactive tuberculosis.

Question 15

How is it that tuberculosis might lead to bronchiectasis in different manners?

Answer 15

“In areas where tuberculosis is prevalent, bonchiectasias more frequently occurs as a sequela of granulomatous infection. Focal bronquiectasias can arise from extrinsic compression of the airway by enlarged granulomatous lymph nodes and/or from development of intrinsic obstruction as a result of erosion of a calcified lymph node through the airway wall (e.g. broncholithiasis). Especially in reactivated tuberculosis, parenchymal destruction from infection can result in areas of more diffuse bronchiectasis.”

Question 16

The incidence of bronchiectasias is increasing in developed as well as developing countries.
True or False?

Answer 16

True.

Question 17

How might malnutrition lead to bronchiectasis?

Answer 17

“Apart from cases associated with tuberculosis, an increased incidence of non-CF bronchiectasis with an unclear underlying mechanism has been reported as a significant problem in developing nations. It has been suggested that the high incidence of malnutrition in certain areas may predispose to immune dysfunction and development of bronchiectasis.”

Question 18

Bordetella pertussis and Mycoplasma pneumoniae might induce significant airway damage and poor secretion clearance.
True or False?

Answer 18

True.

Question 19

Name one bacteria that has propensity for colonizing damaged airways and evade host defense mechanisms.

Answer 19

Pseudomonas aeruginosa.

thus, it’s presence might indicate a poor prognosis in some bronchiectasis

Question 20

Name three mechanisms that might impair muocilliary clearance.

Answer 20

Inherited diseases such as cystic fibrosis and dyskinetic cilia syndomre and “it has been proposed that mediators released directly from bacteria can interfere with mucociliary clearance.”

Question 21

Explain the “vicious cycle hypothesis”.

Answer 21

“susceptibility to infection and poor mucociliary clearance result in microbial colonization of the bronchial tree.”

“The presence of the microbes incites continued chronic inflammation, with consequent damage to the airway wall, continued impairment of secretion and microbial clearance, and ongoing propagation of the infectious/inflammatory cycle.”

Question 22

Do proteases have any pathological importance in bronchiectasis? If so, explain how so and the relantionship with alpha1-antitrypsin deficiency.

Answer 22

“Classic studies (…) demonstrated significant small-airway wall inflammation and larger-airway wall destruction as well as dilation, with loss of elastin, smooth muscle, and cartilage. It has been proposed that inflammatory cells in the small airways release proteases and other mediators, such as reactive oxygen species and proinflammatory cytokines, that damage larger-airway walls. (….) It is thought that antiproteases, such as alpha1-antitrypsin, play an important role in neutralazing the damaging effects of neutrophil elastase and in enchancing bacterial killing.”

Question 23

Bronchiectasis in allergic bronchopulmonary aspergillosis are predominantly centrally located and are due to the invading capacity of Aspergillus.
True or False?

Answer 23

False.
The pulmonary destruction is due to the immune response against the Aspergillus. The fungus in itself has no capacity of invading the airway wall.

Question 24

Give two examples of conditions that lead to traction bronchiectasis.

Answer 24

Postradiation fibrosis and idiopathic pulmonary fibrosis.

Question 25

What is the most common clinical presentation of bronchiectasis?

Answer 25

"persistent productive cough with ongoing production of thick, tenacious sputum."

Question 26

Name the causes of clubbing of the digits.

Answer 26

- Respiratory causes: primary and secondary neoplasia, mesothelioma, bronchiectasis and cystic fibrosis, chronic supurations (such as abcessed infections), tuberculosis, sarcoidosis and asbestosis (but not chronic pulmonary obstructive diseaes). - Cardiologic causes: right-to-left shunting (cyanotic congenital cardiopathies) and sub-acute to chronic infective endocarditis. - Gastrointestinal causes: hepatic chirrosis (of any cause) and intestinal inflammatory diseases.

Question 27

Fever is the most common sign in infection of bronchiectasis. True or False?

Answer 27

False. "Acute exacerbations of bronchiectasis are usually characterized by changes in the nature of sputum production, with increased volume and purulence. However, typical signs and symptoms of lung infection, such as fever and new infiltrates, may not be present."

Question 28

What is the imaging modality of choice for confirming bronchectasis?

Answer 28

Chest computed tomography.

Question 29

What do you expect to find in radiographs and chest computed tomography (CT) of patients with mild to moderate bronchiectasis?

Answer 29

"Although chest radiographs lack sensitivity, the presence of "tram tracks" indicating dilated airways is consistent with bronchiectasis." "CT findings include airway dilation (detected as parallel "tram tracks" or as the "signet-ring sign" - a cross-sectional area of the airway with a diameter at least 1,5 times that of the adjacent vessel), lack of bronchial tapering (including the presence of tubular structures within 1 cm from the pleural surface), bronchial wall thickening in dilated airways, inspissated secretions (e.g., the "tree-in-bud" pattern), or cysts emanating from the bronchial wall (especially pronounced in cystic bronchiectasis)."

Question 30

How do you explain the fact that focal bronchiectasis almost always requires bronchoscopy?

Answer 30

This test is fundamental to exclude obstruction by an underlying mass or foreign body.

Question 31

Which bacteria should one expect in acute exacerbation of bronchiectasis?

Answer 31

Haemophilus influenzae and Pseudomonas aeruginosa are commonly isolated. As for the non-tuberculosis mycobacteria, MAC strains are the most common.

Question 32

What are the criteria for true diagnosis of non-tuberculosis mycobateria infection (NTM)? If they are positive, how would you treat the patient?

Answer 32

"Consensus guidelines have advised that diagnostic criteria for true clinical infection with NTM should be considered in patients with symptoms and radiographic findings of lung disease who have at least two sputum samples positive on culture; at least one bronchoalveolar lavage (BAL) fluid sample positive on culture; a biopsy sample displaying histopathologic features of NTM infection (e.g., granuloma or a positive strain for acid-fast bacilli) along with one positive sputum culture; or a pleural fluid sample (or a sample from another sterile extrapulmonary site) positive on culture. MAC strains are the most common NTM pathogens, and the recommended regimen for HIV-negative patients includes a macrolide combined with rifampin and ethambutol. Consesus guidelines also reccomend macrolide susceptibility testing for clinically significant MAC isolates."

Question 33

Non-Cystic Fibrosis (CF) bronchiectasis should also be treated with mucolytic dornase (DNase). True or False?

Answer 33

False. | There are concerns about lack of efficacy and potencial harm in the non-CF population.

Question 34

Which type of interventions lead to bronchial hygiene?

Answer 34

Hydration, mucolytic administration, aerosolization of bronchodilators and hyperosmolar agentes (e.g., hypertonic saline), and chest physiotherapy (e.g., postural draingage, traditional mechanical chest percussion via hand clapping to the chest, or use of devices such as an oscillatory positive expiratory pressure flutter valve or a high-frequency chest wall oscillation vest), and dornase (for cystic fibrosis).

Question 35

Should all patients with bronchiectasis be trated with glucocorticoids?

Answer 35

Short answer, it depends on the etiology of the bronchiectatic process. "small-scale trials have yielded evidence of alleviated dyspnea, decreased need for inhaled beta-agonists, and reduced sputum production wth inhaled glucocorticoids. However, no significant differences in lung function or bronchiectasis exacerbation rates have been observed. Risks of immunosuppression and adrenal suppresion must be carefully considered with use of anti-inflammatory therapy in infectious bronchiectasis. Nevertheless, administration of oral/systemic glucocorticoids may be important in treatment of bronchiectasis due to certain etiologis, such as ABPA, or of noninfectious bronchiectasis due to underlyng conditions, especially that in which an autoimmune condition is believed to be active."

Question 36

Which therapy should you consider in the following situations: (i) non-tuberculosis mycobacteria infection; (ii) allergic bronchopulmonary aspergillosis; (iii) hypogammaglobulinemia-

Answer 36

(i) Macrollide, rifampin and ethambutol. (ii) Glucocorticoids (oral/systemic) and itroconazole. (iii) Gamma-globulin

Question 37

Surgery, besides lung transplantion, is never indicated in bronchiectasis. True or False?

Answer 37

False. | The focal resection of an area of suppuration might be considered in refractory cases.

Question 38

How do you treat hemoptysis due to injury of the superficial mucosal vessels in the context of recurrent infections?

Answer 38

"hemoptysis usually requires intubation to stabilzie the patient, identification of the source of bleeding, and protection of the nonbleeding lung. Control of bleeding often necessitates bronchial artery embolization and, in severe cases, surgery."

Question 39

Compare the declining of forced expiratory volume in 1 sec (FEV1) in patients with non-cystic fibrosis bronchiectasias versus healthy controls.

Answer 39

50-55mL per year declined in the former group in comparison to 20-25mL per year in the latter group.

Question 40

Which types of preventive therapy is there for bronchiectasis?

Answer 40

"the use of suppressive antibiotics to minimize the microbial load and reduce the frequency of exacerbations has been proposed, although these is less consensus with regard to this approach in non-CF-associated bronchiectasis than in patients with CF-related bronchiectasis. Possible suppressive treatments include: (1) administration of an oral antibiotic (e.g., ciprofloxacin) daily for 1-2 weeks per month; (2) use of a rotating schedule orf oral antibiotics (to minimizew the risk of development of drugs resistance); (3) administration of a macrolide antibiotic (see below) daily or three times per week (with mechanisms of possible benefit related to non-antimicrobial properties, such as anti-inflammatory effects and reduction of gram-negativbe bacillary biofilms); (4) inhalation of aerosolized antibiotics (e.g., tobramycin inhalation solution) by selected patients on a rotating schedule (e.g., 30 days on, 30 days off), with the goal of decreasing the microbial load without eliciting the side effects of systemic drug administration; and (5) intermitent administration o fIV antibiotics (e.g., "clean-outs") for patients with more severe bronchiectasis and/or resistant pathogens."

Question 41

Although macrolides decrease the rate at which the lung function deteriorates in non-cystic fibrosis bronchiectasias, as well as mucus production and exacerbations, it is not universally recommended for this population. How do you explain it?

Answer 41

Two studies demonstrated an increased macrolide resistance in commensal pathogens. "In particular, development of macrolide-resistant non-tuberculoisis mycobacteria is a significant concern, making treatment of that pathogen much more difficult."