📄 bronchiectasis
ESSENTIALS OF DIAGNOSIS
Chronic productive cough with dyspnea and wheezing
Radiographic findings of dilated, thickened airways and scattered, irregular opacities
General Considerations
Bronchiectasis is a congenital or acquired disorder of the large bronchi characterized by permanent, abnormal dilation and destruction of bronchial walls
It may be caused by recurrent inflammation or infection of the airways and may be localized or diffuse
Cystic fibrosis causes about half of all cases of bronchiectasis
Other causes include lung infection (tuberculosis, fungal infections, lung abscess, pneumonia), abnormal lung defense mechanisms (humoral immunodeficiency, alpha-1-antitrypsin deficiency with cigarette smoking, mucociliary clearance disorders, rheumatic diseases), and localized airway obstruction (foreign body, tumor, mucoid impaction)
Immunodeficiency states that may lead to bronchiectasis include congenital or acquired panhypogammaglobulinemia; common variable immunodeficiency; selective IgA, IgM, and IgG subclass deficiencies; and acquired immunodeficiency from cytotoxic therapy, AIDS, lymphoma, plasma cell myeloma (previously called multiple myeloma), and leukemia
Most patients with bronchiectasis have panhypergammaglobulinemia, however, presumably reflecting an immune system response to chronic airway infection
Clinical Findings
Symptoms and Signs
Symptoms of bronchiectasis include chronic cough with production of copious amounts of purulent sputum, hemoptysis, and pleuritic chest pain
Dyspnea and wheezing occur in 75% of patients
Weight loss, anemia, and other systemic manifestations are common
Physical findings are nonspecific, but persistent crackles at the lung bases are common
Clubbing is infrequent in mild cases but is common in severe disease
Copious, foul-smelling, purulent sputum is characteristic
Obstructive pulmonary dysfunction with hypoxemia is seen in moderate or severe disease
Imaging Radiographic
abnormalities include dilated and thickened bronchi that may appear as “tram tracks” or as ring-like markings
Scattered irregular opacities, atelectasis, and focal consolidation may be present
High-resolution CT is the diagnostic study of choice
Microbiology
H influenzae is the most common organism recovered from non–cystic fibrosis patients with bronchiectasis
P aeruginosa, S pneumoniae, and Staphylococcus aureus are commonly identified
Nontuberculous mycobacteria are seen less commonly
Patients with Pseudomonas infection experience an accelerated course, with more frequent exacerbations and more rapid decline in lung function
Treatment
Treatment of acute exacerbations consists of antibiotics, daily chest physiotherapy with postural drainage and chest percussion, and inhaled bronchodilators
Handheld flutter valve devices may be as effective as chest physiotherapy in clearing secretions
Antibiotic therapy should be guided by sputum smears and prior cultures
If a specific bacterial pathogen cannot be isolated, then empiric oral antibiotic therapy for 10–14 days is appropriate
Common regimens include amoxicillin or amoxicillin-clavulanate (500 mg every 8 hours), ampicillin (250–500 mg four times daily), doxycycline (100 mg twice daily), trimethoprimsulfamethoxazole (160/800 mg every 12 hours), or ciprofloxacin (500–750 mg twice daily)
It is important to screen patients for infection with nontuberculous mycobacteria because these organisms may underlie a lack of treatment response
Preventive or suppressive treatment is sometimes given to stable outpatients with bronchiectasis who have copious purulent sputum
Prolonged macrolide therapy (azithromycin 500 mg three times a week for 6 months or 250 mg daily for 12 months) has been found to decrease the frequency of exacerbations compared to placebo
Alternating cycles of the antibiotics listed above given orally for 2–4 weeks are also used in patients who are not colonized with Pseudomonas, although this practice is not supported by clinical trial data
In patients with underlying cystic fibrosis, inhaled aerosolized aminoglycosides reduce colonization by Pseudomonas species, improve FEV1, and reduce hospitalizations; in patients with non–cystic fibrosis bronchiectasis, the role of inhaled aerosolized aminoglycosides is unclear
Complications of bronchiectasis include hemoptysis, cor pulmonale, amyloidosis, and secondary visceral abscesses at distant sites (eg, brain)
Bronchoscopy is sometimes necessary to evaluate hemoptysis, remove retained secretions, and rule out obstructing airway lesions
Massive hemoptysis may require embolization of bronchial arteries or surgical resection
Surgical resection is otherwise reserved for the few patients with localized bronchiectasis and adequate pulmonary function in whom conservative management fails
