Bronchiectasis is a chronic lung disease resulting from dilatation of bronchi due to a variety of causes and propagated through an interplay of host factors, environment, and respiratory pathogens. Clinically, it is marked by a syndrome of cough, sputum production, and recurrent respiratory infections. It is confirmed radiographically by a lack of bronchial tapering and a bronchus-to-arterial ratio greater than 1.5. It can be divided into cylindric, varicose, and cystic subtypes, which often overlap and coexist, but may aid in diagnosis and overall prognosis.

• The incidence and prevalence of bronchiectasis is steadily rising in the U.S. and Europe.^1-4 Prevalence increases markedly with age, with peak incidence in those older than age 65. In the U.S., the average annual prevalence was approximately 700 per 100,000 persons among Medicare beneficiaries between 2012 and 2014,⁵ with likely higher prevalence given noted escalations of incidence.
• Bronchiectasis is more common in women than men.
• There are multiple identified etiologies that can vary by geographic region, yet idiopathic remains the most frequent diagnosis worldwide.⁶
• Table 1 summarizes conditions associated with bronchiectasis.

• Chronic cough, typically with expectoration of purulent sputum
• Frequent bronchitis or pneumonias requiring antibiotic treatment
• Generalized malaise and/or weight loss
• Fever and/or night sweats
• Hemoptysis
• Crackles, wheezing, or squeaks on lung exam
• Halitosis

• Postinfectious (e.g., previous pneumonia, lung abscess, tuberculosis, nontuberculous mycobacterial infections, fungal infections, viral infections)
• Cystic fibrosis
• Ciliary dysfunction (primary ciliary dyskinesia, Kartagener syndrome)
• Chronic obstructive pulmonary diseases (e.g., chronic obstructive pulmonary disease [COPD], asthma)
• Impaired host defense (e.g., hypogammaglobulinemia, acquired immunodeficiency syndrome, chemotherapy)
• Localized airway obstruction (aspiration, congenital structural defects, foreign bodies, neoplasms)
• Inflammation (chronic gastroesophageal reflux disease [GERD], inflammatory pneumonitis, granulomatous lung disease, allergic aspergillosis)
• Congenital disorders such as tracheobronchomegaly (Mounier-Kuhn syndrome), cartilage deficiency (Williams-Campbell syndrome, Marfan syndrome), alpha-1 anti-trypsin deficiency
• Connective tissue and autoimmune diseases (Sjogren disease, ulcerative colitis, rheumatoid arthritis)
• Cellular pathophysiologic mechanism of bronchiectasis is illustrated in Fig. E1

• Chronic bronchitis or chronic rhinosinusitis
• Chronic obstructive pulmonary disease
• Asthma
• Tuberculosis
• Interstitial fibrosis
• Chronic lung abscess
• Foreign body aspiration
• Cystic fibrosis
• Lung carcinoma
• Gastroesophageal reflux disease
• Diffuse panbronchiolitis
• Bronchiolitis obliterans

• Pulmonary function tests with bronchodilators
• Sputum for Gram stain, culture and susceptibilities, and acid-fast bacteria
• Serum immunoglobulins (total immunoglobulin A [IgA], IgM, IgG and subclasses)
• Testing for allergic bronchopulmonary aspergillosis (serum IgE, precipitating IgG antibodies [precipitins] to Aspergillus, specific IgE antibodies to Aspergillus, Aspergillus skin test)
• CBC with differential (leukocytosis with left shift, anemia)
• Alpha-1 antitrypsin level and phenotype
• Sweat test in patients with suspected cystic fibrosis
• Primary ciliary dyskinesia evaluation when suspected
• Antinuclear antibody, rheumatoid factor, and SSA/SSB when driven by history or exam
• Serum anti-Pseudomonas aeruginosa (PA) IgG antibody testing is highly accurate to detect chronic PA colonization in bronchiectasis patients⁷ and may be a marker of treatment response

• Chest x-ray examination (Fig. 2 and Fig. E3) may be normal or have crowded lung markings, “tram-track” sign of dilated bronchi, or small cystic spaces at the base of the lungs.
• High-resolution computed tomography (CT) scan of the chest (Fig. 4 and Figs. E5 to E7 to ) is the gold standard of diagnosis.
  1. The CT study should be noncontrast with the use of a 1- to 1.5-mm window every 1 cm with acquisition time of 1 sec.
  2. Findings include enlarged bronchoarterial ratio of >1.5 (normal 0.7), lack of tapering of an airway toward the periphery, ballooned cysts at the end of bronchi, and airway mucus impaction.
  3. Radiographic examples of different forms of bronchiectasis are illustrated in Fig. E8.
• Bronchoscopy may be helpful to evaluate hemoptysis, rule out obstructive lesions, removal of impacted mucus plugs, and obtain microbiologic data on respiratory pathogens when expectorated or induced sputum is not attainable.
• Table 2 summarizes diagnostic studies for the classification and management of patients with bronchiectasis.

• Mucus clearance is essential and central to therapy: Low risk and shown to improve chronic symptoms of cough, breathlessness, and may reduce frequency of exacerbations. Techniques include positive expiratory pressure (e.g., Acapella, Aerobika), chest wall oscillation (i.e., vest therapy), and chest percussion (e.g., caregiver cupping hand with aggressive patting).
• Exercise, particularly aerobic and/or active breathing (e.g., yoga)
• Supplemental oxygen for hypoxemia
• Nocturnal positive pressure for hypercarbia in advanced disease

• Antibiotic therapy should be based on the results of sputum gram stain, culture, and susceptibility testing, and continued for 14 days of therapy. In those with inadequate or inconclusive sputum test results, therapy can be based on knowledge of past culture growth, or empiric with doxycycline, fluoroquinolone, or amoxicillin/clavulanate for broader coverage.
• Intravenous antibiotics should be used in patients who require hospitalization, such as signs of respiratory distress, systemic symptoms, or inability to improve with oral outpatient therapy.
  1. Hospital admission should focus on mucus clearance and a nutrition assessment.
  2. Evaluate for hypoxemia and need for supplemental supplies prior to discharge.
• Bronchodilators are useful in patients with demonstrable airflow obstruction.
  1. Avoid inhaled corticosteroids if able as there is a strong association of nontuberculous mycobacterium colonization with their use.

• Avoidance of tobacco
• Maintenance of proper nutrition and hydration
• Daily exercise

• Infections should be promptly identified and treated.
• Adults with bronchiectasis with a new isolation of P. aeruginosa should be offered eradication antibiotic treatment. This should not be offered to adults with bronchiectasis following new isolation of pathogens other than P. aeruginosa.⁸
  1. Measurement of serum anti-Pseudomonas aeruginosa (PA) IgG antibody may help predict success.⁷
• Bronchodilators should be used before physiotherapy, including inhaled mucoactive drugs and inhaled antibiotics, in those with evidence of obstructive ventilatory defect or bronchospasm. This increases tolerability and optimizes delivery of medications in diseased areas of the lungs.
• Inhaled corticosteroids should not be offered to adults with isolated bronchiectasis. However, the diagnosis of bronchiectasis should not affect the use of inhaled corticosteroid in patients with comorbid asthma.
• Inhaled hyperosmolar agents (e.g., hypertonic saline) should be considered in conjunction with airway clearance in patients who have difficulty expectorating sputum.
• Inhaled mucolytics can be considered in those with difficulty expectorating sputum, poor quality of life, or where standard airway clearance has failed to control symptoms. However, rhDNase should not be offered to patients with bronchiectasis not related to cystic fibrosis as there is an associated decline in forced expiratory volume in the first second (FEV₁) and forced vital capacity in this population.⁹
• Macrolide thrice weekly should be offered for adults with bronchiectasis who have three or more exacerbations per year.¹⁰
• Immunoglobulin replacement should be considered in patients with selective immunoglobulin deficiency.

• Prognosis is variable with severity of the disease and underlying etiology of bronchiectasis. The bronchiectasis severity index is one helpful scoring system.^11,12
• Pulmonary function declines at a faster rate in those with Pseudomonas colonization or frequent exacerbations.
• Concomitant rheumatoid arthritis or COPD is associated with worse prognosis.

• Surgical partial lung resection may be an option in patients with localized disease, severe disease unresponsive to medical therapy, or in patients with massive hemoptysis. Surgical resection of localized bronchiectasis is safe and improves quality of life.
• Embolization should be considered for recurrent hemoptysis.
• Referral for lung transplant should be considered similarly to patients with cystic fibrosis.

• The activity and quantity of neutrophil serine proteases are increased in the sputum of patients with bronchiectasis at baseline and increase further during exacerbations. A phase 2 trial revealed a reduction of neutrophil serine protease activity with brensocatib, an oral reversible inhibitor of dipeptidyl peptidase 1 (DPP-1), an enzyme responsible for the activation of neutrophil serine proteases.¹³ There is ongoing clinical investigation of this agent.
• Other potential therapeutics being considered in bronchiectasis include novel inhibitors of dipeptidyl peptidase 1, antagonism of CXC chemokine receptor 2, and immunomodulatory drugs.¹⁴
• Patients with bronchiectasis are susceptible to nontuberculous mycobacterium pulmonary infection. Consider periodically screening using acid fast bacillus sputum cultures, and directly testing when there is a change in symptoms or clinical course.

Bronchiectasis (Patient Information)