BRONCHIECTASIS

BRONCHIECTASIS - Dylan C. Kwait, MD
BASICS
DESCRIPTION
Irreversible dilatation of 1 or more airways accompanied by recurrent bronchial infection/inflammation and chronic mucopurulent sputum production; generally classified into cystic fibrosis (CF) and non-cystic fibrosis (non-CF) bronchiectasis.
ALERT
Geriatric Considerations
Elderly are more likely to need hospitalization for treatment.
Pediatric Considerations
Associated with childhood respiratory infections, CF, and other congenital conditions.
GENERAL PREVENTION
• Immunize against
- Pertussis, measles, Haemophilus influenza type B (in childhood)
- Viral illnesses (influenza)
- Pneumococcal pneumonia
• Genetic counseling in cases in which a congenital condition may increase the likelihood of developing bronchiectasis
• Adequate treatment of all pneumonias
EPIDEMIOLOGY
• Still a significant cause of respiratory morbidity
• Predominant age: Most commonly presents in 6th decade of life (1)[A]
• Predominant sex: Female > Male (1)[A]
Incidence
Incidence has decreased in the US secondary to widespread childhood vaccination against pertussis (2)[A] and the effective treatment of childhood respiratory infections with antibiotics (1)[A].
Prevalence
• Prevalence in the adult US population estimated to be at least 110,000 (1)[A].
• Prevalence is 5 to 10 times higher in those >55 years of age (3)[B]
RISK FACTORS
• Severe respiratory infection in childhood (measles, adenovirus, influenza, pertussis, or bronchiolitis)
• Predisposing congenital condition
• Systemic diseases (e.g., rheumatoid arthritis and connective tissue disorders)
• Chronic rhinosinusitis
• Recurrent pneumonia
• Aspirated foreign body
• Immunodeficiency
PATHOPHYSIOLOGY
"Vicious cycle hypothesis": Transmural infection, generally by bacterial organisms, causes inflammation and obstruction of airways. Damaged airways and dysfunctional cilia foster bacterial colonization, which leads to further inflammation and obstruction (2)[A].
ETIOLOGY
• CF bronchiectasis
• Non-CF bronchiectasis
- Most cases are idiopathic (4)[B].
- The etiologic agent most commonly associated with non-CF bronchiectasis is childhood respiratory infection (2)[A].
- May be associated with many conditions.
ASSOCIATED CONDITIONS
• Mucociliary clearance defects
- Primary ciliary dyskinesia
- Young syndrome (secondary ciliary dyskinesia)
- Kartagener syndrome
• Other congenital conditions
- 1-Antitrypsin deficiency
- Marfan syndrome
- Cartilage deficiency (Williams-Campbell syndrome)
• Chronic obstructive pulmonary disease
• Postinfectious conditions
- Bacteria (H. influenzae and Pseudomonas aeruginosa)
- Mycobacterial infections (TB and MAC)
- Whooping cough
- Aspergillus species
- Viral (HIV, adenovirus, measles, influenza virus)
• Immunodeficient conditions
- Primary
 Hypogammaglobulinemia
- Secondary
 Allergic bronchopulmonary aspergillosis
 Post-transplantation
• Sequelae of toxic inhalation or aspiration (e.g., chlorine, luminal foreign body)
• Rheumatic/chronic inflammatory conditions:
- Rheumatoid arthritis
- Sjogren syndrome
- Systemic lupus erythematosus
- Inflammatory bowel disease
• Miscellaneous
- Yellow nail syndrome


DIAGNOSIS
SIGNS AND SYMPTOMS
Symptoms are commonly present for many years and include
• Chronic cough (90%) (1)[A]
• Sputum: copious and purulent (90%) (1)[A]
• Rhinosinusitis (60-70%) (1)[A]
• Fatigue, may be a dominant symptom (70%) (1)[A]
• Dyspnea (75%) (2)[A]
• Chest pain, may be pleuritic (20-30%)(1)[A]
• Hemoptysis (20-30%) (1)[A]
• Wheezing (20%)(1)[A]
History
It is vital to elicit
• Time course of illness
• Any predisposing factors (either congenital, infectious, and/or exposure-related)
• Immunization history
Physical Exam
• Bi-basal crackles (60%) (1)[A]
• Wheezing (34%) (2)[A]
• Rhonchi (44%) (2)[A]
• Digital clubbing (3%) (2)[A]
TESTS
• Spirometry
- Limited use in diagnosis
- Characterized by moderate airflow obstruction and hyperresponsive airways (1)[A]
- FEV180% predicted and FEV1/FVC 0.7 (3)[B]
• Special tests
- Ciliary biopsy by electron microscopy
Lab
• Sputum culture
- H. influenzae, nontypeable form (42%) (1)[A]
- P. aeruginosa (18%) (1)[A]
- Cultures may also be positive for Streptococcus pneumoniae, Moraxella catarrhalis, MAC, and Aspergillus (1)[A]
- 30-40% of all isolates will show no growth (1)[A]
• Special tests
- Sweat test for CF
- PPD test for TB
- Skin test for Aspergillus
- HIV test
- Serum immunoglobulins to test for humoral immunodeficiency
Imaging
• CT scan
- Noncontrast high-resolution CT (HRCT) is the most important tool used to diagnose bronchiectasis (2)[A].
- Bronchi are dilated and do not taper; varicose constrictions and ballooned cysts may also be appreciated (2)[A].
• Chest radiograph
- Nonspecific findings; sensitivity and specificity are too low to confirm the diagnosis (3)[B]
- Increased lung markings (1)[A]
- May be normal
Diagnostic Procedures/Surgery
Interventional bronchoscopy
• Used to obtain culture and evacuate sputum
Pathological Findings
• Dilatation of airways (2)[A]
• Thickened bronchial walls with necrosis of bronchial mucosa (2)[A]
• Peribronchial scarring (2)[A]
DIFFERENTIAL DIAGNOSIS
• Chronic obstructive pulmonary disease
• Asthma
• CF
• Chronic bronchitis
• Pulmonary tuberculosis
• Allergic bronchopulmonary aspergillosis
TREATMENT
Treatment of non-CF bronchiectasis involves determining the cause of exacerbations, promoting good bronchopulmonary hygiene through daily airway clearance, and surgical resection of damaged lung when necessary.
STABILIZATION
Hemoptysis, although rare, may occur and can be life threatening. Appropriate measures must be taken to minimize blood loss.
GENERAL MEASURES
• Dry powder mannitol improves tracheobronchial clearance (1)[A]
• Maintain hydration (nebulized saline may be used) (2)[A]
• Noninvasive positive-pressure ventilation (2)[A]
Diet
No dietary restrictions
Activity
Regular exercise is recommended.
Physical Therapy
Sputum clearance techniques
• Physiotherapy (percussion and postural drainage)
• Pulmonary rehabilitation (improves exercise tolerance, but does not benefit from Inspiratory muscle training) (1)[A]
MEDICATION (DRUGS)
First Line
• Antibiotics
- May be used in acute exacerbations
- Chronic therapy decreases sputum volume and purulence, but does not diminish the frequency of exacerbations (5)[A].
- Patients may require twice the usual dose and should receive long courses of treatment (7-14 days) (3)[B].
- Selection is complicated by the wide range of pathogens involved and the existence of resistant organisms (culture should be used to direct therapy).
- Augmentin (3)[B]: 500 mg PO q8-12h for 7-10 days (pediatric: Base dosing protocol on amoxicillin content)
- Trimethoprim-sulfamethoxazole (3)[B]: 160 mg TMP/800 mg SMZ PO q12h for 10-14 days (pediatric: 2 months, 8 mg/kg TMP and 40 mg/kg SMZ PO per 24 hours, administered in 2 divided doses q12h for 10 days)
- Doxycycline and cefaclor given orally are also effective (3)[B].
- Nebulized aminoglycosides (tobramycin): 300 mg by aerosol b.i.d. (6)[B]
- Macrolides appear to have immunomodulatory benefits (1)[A].
- Antibiotics should be administered IV in cases of severe infection.
• Bronchodilators
- Chronic use of -2 agonists (e.g., albuterol) effectively reverses airflow obstruction (1)[A].
• Inhaled corticosteroids
- Decrease sputum and tend to improve lung function (3)[B]
- Fluticasone: 110-220 mcg inhaled b.i.d.
• Contraindications: Documented hypersensitivity
• Precautions: Cross-allergy and organ impairment
• Significant possible interactions: Broad-spectrum antibiotics may reduce efficacy of oral contraceptives
Second Line
Other broad-spectrum antimicrobials including antipseudomonals.
SURGERY
Surgery should be considered in cases in which disease is localized and symptoms remain intolerable despite medical therapy. Surgery effectively improves symptoms in 80% of these cases (1)[A].
FOLLOW-UP
PROGNOSIS
• Mortality rate is 13% (death due directly to bronchiectasis) (1)[A].
• Pseudomonas infection is associated with poorer prognosis (1)[A].
COMPLICATIONS
• Hemoptysis
• Recurrent pulmonary infections
• Pulmonary hypertension
• Cor pulmonale
• Lung abscess
PATIENT MONITORING
• Serial spirometry, performed every 2-5 years, should be used to monitor the course of the disease (1)[A].
• Routine microbiological sputum analysis (1)[A].
• Annual influenza and pneumococcal immunizations (3)[B].
REFERENCES
1. King P, Holdsworth S, Freezer N, Holmes P. Bronchiectasis. Intern Med J. 2006;36(11):729.
2. Barker AF. Bronchiectasis. N Engl J Med. 2002;346:1383-1393.
3. Bradley J, Lavery K, Rendall J, Elborn JS. Managing bronchiectasis. Practitioner. 2006;250(1681):194.
4. Pasteur MC, Helliwell SM, Houghton SJ, et al. An investigation into the causative factors in patients with bronchiectasis. Am J Respir Crit Care Med. 2000;162:1277-1284.
5. Evans DJ, Bara AI, Greenstone M. Prolonged antibiotics for purulent bronchiectasis. Cochrane Database of Sys Rev. 2006;(4):CD00284.
6. Lobue PA. Inhaled tobramycin: Not just for cystic fibrosis anymore? Chest. 2005;127:1098.
MISCELLANEOUS
See also: Cystic fibrosis; Chronic obstructive pulmonary disease; Asthma; Pulmonary tuberculosis; Aspergillosis; Kartagener syndrome