Topic Editor: Robert Giles, MBBS, BPharm
Review Date: 9/8/2012
Definition 
Bronchiectasis is the permanent abnormal dilation of bronchi with destruction of the muscular and elastic elements of the bronchial wall. It is most often caused by infectious insults in a predisposed individual
Description
Bronchiectasis is a chronic and progressive condition characterized by airway obstruction, dyspnea, and impaired clearance of respiratory secretions. It is accompanied by a chronic debilitating cough with mucopurulent secretions and sometimes hemoptysis
- Severe cases may progress to respiratory failure
- Bronchiectasis is mainly a focal process affecting a lobe, segment, or sub-segment of the lung. In some cases, diffuse involvement of one or both lungs can occur
- Bronchiectasis can be classified as
- Cystic fibrosis (CF) bronchiectasis: Primarily caused by cystic fibrosis
- Non-cystic fibrosis (non-CF) bronchiectasis: Mainly caused by recurrent respiratory infections, immune conditions, genetic disorders and idiopathic causes
- There is evidence of an increasing global prvalence of bronchiectasis, particularly in developing countries
- Pathophysiology: Caused by a vicious cycle of transmural bacterial infection, inflammation and obstruction, followed by increased bacterial colonization which is promoted by damaged airways and impaired cilia
Epidemiology
Incidence/prevalence
- The incidence of bronchiectasis has significantly declined in developed nations due to the emergence of vaccines and antibiotics, but it remains a major concern in the developing world
- The estimated prevalence of bronchiectasis is 4 per 100,000 persons in individuals aged 18 to 34 years, and 272 per 100,000 among those aged
75 years. Based on this data an estimated 110,000 people may be affected in the United States
Age
- Bronchiectasis affects individuals of all ages, though its prevalence increases with age
Gender
- Bronchiectasis more commonly affects females than males
- Females typically have more severe disease than males
- The most common patient with bronchiectasis is an older female
Race
- No racial predilection (other than associated socioeconomic conditions) has been noted
Risk factors
- alpha 1- antitrypsin deficiency
- Chronic rhinosinusitis
- Congenital bronchial conditions
- Cystic fibrosis
- Airway obstruction (eg foreign body aspiration, cancers, mucoid impaction, postoperative)
- History of severe childhood respiratory infections (bacterial, fungal, viral)
- Immunodeficiency states
- Nontuberculous mycobacterial infection
- Primary ciliary dyskinesia
- Recurrent pneumonia
- Systemic diseases ( eg connective tissue disorders, inflammatory bowel disease, rheumatoid arthritis)
- Post transplantation
Etiology
Bronchiectasis primarily occurs as a result of recurrent pulmonary infection in combination with impaired drainage, airway obstruction and/or a defect in host defense. This leads to chronic inflammation and progressive bronchial damage. Predisposing factors which promote recurrent infections are classified as follows:
- Idiopathic causes (5-50%), particularly in non-CF bronchiectasis
- Genetic factors
- alpha-1-antitrypsin deficiency
- Ciliary dyskinesia
- Cystic fibrosis
- Kartagener's syndrome (situs inversus, primary ciliary dyskinesia, sinusitis/bronchiectasis)
- Post-infectious causes
- History of childhood viral respiratory infections (measles, influenza, pertussis, respiratory syncytial virus)
- History of bronchopulmonary aspergillosis
- History of mycobacterial infection or severe bacterial pneumonia
- Swyer-James-Macleod syndrome
- Aspiration or inhalation injury
- Gastric aspiration
- Toxic gas inhalation
- Autoimmune diseases
- Rheumatoid arthritis
- Sjogren's syndrome
- Systemic lupus erythematosus
- Bronchial obstruction
- Bronchial stenosis
- Broncholith
- Foreign body aspiration
- Lung neoplasms
- Lymphadenopathy
- Immunodeficiency conditions
- HIV infection
- Immunoglobulin deficiency
- Inflammatory bowel conditions
- Crohn's disease
- Ulcerative colitis
- Others
- Ehlers-Danlos syndrome
- Marfan syndrome
- Mounier-Kuhn syndrome
- Post transplantation
- Pulmonary sequestration
- Williams-Campbell syndrome
- Yellow nail syndrome
- Young's syndrome
[Outline]
History
- Presence of predisposing risk factors (congenital, infectious, and/or exposure-related)
- Chronic cough (98% of patients)
- Voluminous and purulent sputum
- Dyspnea (73% of patients), especially on exertion
- Fatigue, particularly during acute exacerbations
- Hemoptysis (56-92% of patients)
- Intermittent pleuritic chest pain (19-46% of patients )
- Recurrent episodic fever (>50% of patients)
- Urinary incontinence in women
Physical findings on examination
- Bibasilar crackles
- Clubbing of digits (rare)
- Cyanosis and plethora (rare)
- Inspiratory squeaks
- Rhinosinusitis
- Rhonchi
- Weight loss
- Wheeze
[Outline]
Diagnosis of bronchiectasis is based on radiographic findings on high resolution CT. A diagnostic workup is required to identify potentially treatable underlying causes. A selection of the tests listed below, as applicable to the given patient, should be obtained.
Blood test findings
- Complete blood count (CBC)
- CBC may reveal presence of anemia or leukocytosis
- A high neutrophil count is suggestive of exacerbation or secondary infection
- Underlying bronchopulmonary aspergillosis is associated with a high eosinophil count
- In advanced cases, there may be polycythemia secondary to chronic hypoxia
- alpha 1-Antitrypsin Levels
- Quantitative estimation of serum alpha 1-antitrypsin levels is useful for detection of alpha-1 antitrypsin deficiency
- Rheumatoid factor
- A positive rheumatoid factor is indicative of rheumatoid arthritis, which is a predisposing factor for bronchiectasis
- Serum HIV Antibody
- May be used to detect HIV infection, which is a predisposing factor for bronchiectasis
- Serum Immunoglobulin
- In patients with underlying hypogammaglobulinemia, serum immunoglobulin assessment may show diminished IgG, IgM, and/or IgA. Such patients will have lack of appropriate response to Haemophilus influenzae and pneumococcal vaccines
Other laboratory test findings
- Sputum analysis
- Sputum evaluation may substantiate the diagnosis of bronchiectasis; it may also help determine specific infectious etiologic factors
- Sputum culture and gram stain may identify pathogenic organisms. Common bacteria identified include:
- gram-positive cocci (eg Streptococcus pneumonia, Staphylococcus aureus, beta hemolytic streptococcus)
- gram-negative bacteria (eg pseudomonas species, Escherichia coli, Haemophilus influenzae, Klebsiella pneumonia, Moraxella catarrhalis, Serratia marcescens)
- The isolation of Pseudomonas in the sputum is important as it affects both treatment and prognosis
- Smear and culture of sputum may be useful for detection of fungal agents such as Aspergillus and atypical mycobacteria
Radiologic findings
- Computed tomography (CT) scan
- High-resolution CT (HRCT) scan is the defining diagnostic modality of bronchiectasis, and is recommended in all patients
- HRCT findings in bronchiectasis may include:
- Abnormal bronchial dilation with or without airway thickening
- Bronchi that are cross-sectionally larger in size than their adjacent pulmonary artery
- Fluid-filled cysts
- Mucus plugged airways appear as peripheral V- and Y-shaped markings (tree-in-bud pattern)
Varicose narrowing along airways
- Chest x-ray (CXR)
- CXR has been largely replaced by HRCT but is often the first imaging study ordered. The CXR is likely to be abnormal but findings are usually non-specific
- CXR can be useful for monitoring disease progression
- CXR findings may include
- Crowded pulmonary vascular markings
- Enlargement of pulmonary vessels
- Obscured hemidiaphragm
- Oligemia
- Parallel line opacities (tram lines)
- Thin-walled ring opacities, with or without air-fluid levels
- Tubular opacities
Other diagnostic test findings
- Aspergillus skin prick test
- Development of prompt cutaneous reactivity following exposure to antigen is suggestive of bronchopulmonary aspergillosis
- Bronchoscopy
- Though it has limited value in the diagnosis of bronchiectasis, bronchoscopy may be useful in evaluating for underlying conditions, such as neoplasms, foreign bodies, or other lesions
- Nasal Nitric oxide
- A low nasal nitric oxide level is highly suggestive of primary ciliary dyskinesia
- Pilocarpine iontophoresis test or "Sweat test," is useful in the evaluation of patients for CF. False negatives are possible and if symptoms still suggest CF then other investigations should be considered
- Spirometry
- Pulmonary function test results may be useful in evaluating predisposing conditions and underlying comorbidities
A diminished FEV1 and elevated RV/TLC is suggestive of exacerbations or worsening bronchiectasis
[Outline]
General treatment items
- Antibiotic treatment
- Antibiotics are the primary treatment for recurrent lung infections associated with bronchiectasis. The most common causes are H. influenza, P. aeruginosa, and more rarely S. pneumoniae
- Antibiotics may be administered via oral, parenteral or inhalation routes, based on the severity of the condition and causative organism
- Sputum culture should be obtained and empirical antibiotics commenced while awaiting results. Previous sputum results may help guide therapy
- Oral broad-spectrum antibiotics are generally preferred for mild to moderate acute exacerbations, guided by sputum results
- Empiric treatment commonly will be one of the following:
- Amoxicillin-clavulanate
- Azithromycin
- Ciprofloxacin
- Doxycycline
- Gemifloxacin
- Levofloxacin
- Moxifloxacin
- Tetracycline
- Trimethoprim-sulfamethoxazole
- Once a specific organism is identified, modifying therapy to the most narrow spectrum agent possible is reasonable
- Treatment duration typically ranges from 7–14 days
- Moderate to severe cases require parenteral administration of antibiotics such as gentamicin, tobramycin, third-generation cephalosporins, or advanced fluoroquinolones such as ciprofloxacin, levofloxacin, gemifloxacin or moxifloxacin
- Chronic suppressive therapy is useful in patients with frequent exacerbations. Various regimes have been developed including daily oral/ inhaled doses or short courses of oral / intravenous antibiotics
- Aerosolized antibiotics may be useful in Pseudomonas aeruginosa infections, with minimal systemic effects. Inhaled tobramycin has been effectively used for treatment of CF or non-CF bronchiectasis. Other inhaled antibiotics such as gentamicin and colistin are currently under investigation
- Mycobacterium avium complex (MAC) infection should be treated with a specific combination regimen of clarithromycin or azithromycin along with other anti-tubercular agents for a prolonged duration (18–24 months)
- Anti-inflammatory therapy
- Anti-inflammatory agents may alter the inflammatory response generated by microorganisms associated with bronchiectasis and subsequently limit tissue damage
- The role of inhaled or oral corticosteroids, leukotriene receptor antagonists, and non-steroidal anti-inflammatory drugs (NSAIDs) is unclear with studies showing mixed results. Opinions regarding the use of these agents are currently mixed
- Certain oral macrolides like azithromycin have demonstrated anti-inflammatory properties and are known to improve lung function in patients with P. aeruginosa colonization
- Bronchodilator therapy
- Bronchodilators, including beta-agonists (albuterol) and anticholinergics (ipratropium) may be useful especially in patients with underlying asthma or chronic obstructive pulmonary disease. Randomized trial data to support their effectiveness is lacking
- Surgery
- Patients with advanced or complicated disease, particularly those with focal disease, intractable hemoptysis, or poor response to antibiotics require surgical resection
- Surgical interventions may also be useful for reducing acute infective episodes
- Surgery may be considered to decrease sputum production, control severe hemoptysis, remove foreign bodies or neoplasm, or in the treatment of bronchopulmonary aspergillosis
- Lung transplantation
- Severe bronchiectasis, especially cystic fibrosis-related, may necessitate single or double lung transplantation
- Decline of FEV1 below 30% of the predicted value may prompt transplant consideration
Medication indicated with specific doses
Antibiotics
- Amoxicillin-Clavulanate
- Azithromycin [Oral]
- Azithromycin [IV]
- Ciprofloxacin (oral)
- Ciprofloxacin (IV)
- Clarithromycin
- Doxycycline (oral)
- Gemifloxacin (oral)
- Gentamicin [IM/IV]
- Levofloxacin (oral)
- Levofloxacin (IV)
- Moxifloxacin [IV]
- Moxifloxacin [Oral]
- Sulfamethoxazole/trimethoprim [Oral]
- Tetracycline [Oral]
- Tobramycin [inhaled]
- Tobramycin [IM/IV]
Inhaled corticosteroids
- Beclomethasone [Inhaled]
- Fluticasone [Inhaled]
Bronchodialators
- Albuterol [Inhaled]
- Ipratropium [Inhaled]
Dietary or Activity restrictions
- A healthy, well-balanced and regular diet is recommended for maintaining a body mass index (BMI) >18.5
- Patients should be advised to adhere to a regular exercise program
- Patients should be encouraged to perform airway clearance therapy on a daily basis
[Outline]
Prevention
- Early diagnosis and prompt treatment of underlying etiology may retard the development of bronchiectasis
- Cessation of smoking and avoidance of passive smoke is recommended
- High-risk patients should receive vaccination against Haemophilus influenzae and Streptococcus pneumoniae
Prognosis
- Prognosis of bronchiectasis is difficult to estimate, due to its coexistence with other respiratory conditions
- Bronchiectasis had a reported mortality rate of 13% in 1981. The current mortality rate is difficult to estimate due to lack of studies
- Predictors of mortality include hypoxemia, hypercapnia, intensity of dyspnea, and radiological level of condition
- Chronic P. aeruginosa colonization, severe exacerbations, and systemic inflammation are indicators of poor prognosis
- A higher BMI and vaccination are associated with improved survival
Associated conditions
Pregnancy/pediatric affects on the condition
- Bronchiectasis is relatively unusual during pregnancy; its presence may aggravate the patient's condition
- Bronchiectasis during pregnancy may be associated with intra-uterine growth retardation of the fetus, primarily due to maternal hypoxia
ICD-9-CM
ICD-10-CM
[Outline]
