What are the causes of bronchiectasis? (7-26)
1) Respiratory childhood infection
Pertussis
Measles
TB
2) Bronchial Obstruction
Foreign Body
Chronic Aspiration
Endobronchial tumour
Lymph nodes (TB, sarcoid, malignancy)
Granulomata (TB, Sarcoid, Chediak-Highashi Syndrome)
3) Fibrosis
Long standing pulmonary fibrosis
FIbrosis complicating TB/Sarcoid
Fibrosis complicating unresolved or suppuraitve pneumonia
4) Muco-ciliary clearance of defects
Cystic Fibrosis
Immotile cilia syndrome
Kartagener’s Syndrome
Young syndrome - triad of obstructive male azoospermia (infertility), chronic rhino-sinusitis, and bronchiectasis
5) Immunodeficiency
Congenital and acquired hypogammaglobulinaemia
AIDS
ABPA
6) Autoimmune
RA (Rheumatoid lung)
Sjogrens
IBD (UC>Chron’s)
7) Congenital anatomical defects
Bronchopulmonary sequestration
William Campbell syndrome
Mounier-Kuhn Syndrome
Swyer-James syndrome
Yellow Nail syndrome
What is the pathophysiology of bronchiectasis?
Abnormal bronchial wall dilatation, destruction, and transmural inflammation
Abnormal dilatation of proximal and medium sized bronchi (diameter >2 mm) due to destruction of muscular and elastic components of the bronchial walls.
This leads to inflammation, edema, scarring and ulceration of the bronchial walls
Severely impaired clearance of secretions cause colonization and infection.
This results in further bronchial damage, dilatation, impaired clearance of secretions, recurrent and more bronchial damage (a vicious cycle).
What is traction bronchiectasis?
Distortion of airways secondary to mechanical traction on the bronchi from fibrosis of the surrounding lung parenchyma, leading to airway dilatation and bronchiectasis. Traction bronchiectasis is seen in the setting of pulmonary fibrosis
What are the complications of bronchiectasis?
Pneumonia
Pneumothorax
Empyema
Collapse
Metestatic cerebral abscess (hematogenous spread/seeding)
Respiratory Failure
Pulmonary HTN
Amyloidosis
Is bronchiectasis associated with smoking?
Not per se, however smoking associated with COPD and 30% of patients with COPD have evidence of bronchiectasis on CT
What is the cause and significance of wheeze in a patient
Signifies airway obstruction
1) Airway collapsibility (destruction of muscular and elastic components in bronchial walls)
2) Airway obstruction (secretions, LN, granulomata, malignancy)
3) Co-existent obstructive airway disease
How can the anatomical distribution of bronchiectasis differentiate the cause or associated condition in bronchiectasis?
1) Infection - Lower lobe - RML, and lingula
2) Obstruction - RML
3) TB, Fungal Infections - UL
4) ABPA - UL, involving central bronchi (proximal bronchiectasis), or distal bronchial segments.
What is the role of CT in diagnosing bronchiectasis?
HRCT (resolution is 1-2mm thick compared to 10mm thick in standard CT) = gold standard for diagnosis bronchiectasis
Signet ring sign = bronchial diameter is greater than adjacent vessel diameter
What would the spirometry findings be in this patient?
PFTts = may be normal
Most common abnormality is obstructive pattern (FEV1:FVC <70%)
Not usually reversible (some patients may have airway hyperreactivity that will respond to bronchodilator therapy)
In severe advanced disease, may be restrictive pattern (>70%)
What are the most common resp organisms in bronchiectasis?
1) Staph aureus
2) Haemophilus Influenzae
3) Pseudoamonas Aerguinosa
4) Streptococcus Pneumonia
5) Klebsiella Pneumoniae
6) Aspergillus
What do you know about the different conditions associated with bronchiectasis?
1) Cystic Fibrosis
Autosomal Recessive - occurring in 1/2500. Defect on Cr 7 - delta F508 mutation that encodes CFTR chloride channel, which plays an important role in secretory function in the nasal epithelium, lungs, salivary glands, pancreas, intestines, and bile duct.
Respiratory manifestations: nasal polyps, otitis media, asthma, bronchiolitis, recurrent pneumonia, and bronchiectasis
GI manifestations: meconium ileus (birth), rectal prolapse (neonate), malabsorption, steatorrhea, meconium ileus equivalent (adults), gallstones, and secondary biliary cirrhosis
Other manifestations: non-erosive arthropathy, infertility (males)
2) ABPA
Hypersensitivtiy reaction to Aspergillus fumigatius in patients with asthma or CF => excessive mucus production in association with impaired ciliary function lead to mucoid impaction of the airways. These mucus plugs contain the organism and eosinophils, but the organism remain in bronchial lumen. Precipitating abs produce a type I HS reaction with release of IgE and IgG IG => immune complex and inflammatory cell deposition in bronchial mucosa => T3 HS resulting in damage to bronchial walls with subsequent development of bronchial dilatation and bronchiectasis in the proximal bronchi usually.
3) Chediak-Higashi syndrome
Granulation disorder of lysosomes with reduced myeloperoxidase secretion. Leads to chronic granulomatous disease of the lungs. Death by 10 years of age.
4) Yellow Nail syndrome
Slog rowing, excessively curved (both horizontal and longitudinal) and thickened yellow nails. Also get exudative pleural effusions, bronchiectasis, sinusitis and lymphedema.
5) William Campbell syndrome
Congenital absence of cartilage and a cause of bronchiectasis in the young.
6) Primary Ciliary Dyskinesia (immotile cilia syndrome)
AR - chronic sinusitis, recurrent otitis media, nasal polyps, hypoplastic frontal sinuses, chronic bronchitis, obstructive airway disease, immotile cilia, bronchiectasis (lower lobes) and infertility. Defect in the cilia (axonemel dynein heavy chain protein-DNAH5), making them unable to beat
**7) Kartagener syndrome
**
Variant of immotile cilia syndrome
Dextrocardia + Situs invertus
8) Young syndrome
triad of obstructive male azoospermia (infertility), chronic rhino-sinusitis, and bronchiectasis
Normal ciliary activity, but excessively thick mucous
**9) Mounier-Kuhn (Tracheobronchmegaly)
**
Multiple trachael diverticulae associated with marked dilatation of trachea and main bronchi, bronchiectasis and recurrent respiratory infections
10) Swyer-James Syndrome (MacLeod syndrome)
Manifestation of post-infectious bronchiolitis => diminished vascularity, arrest of progressive growth and alveolirazation of affected lung => hypoplastic lung.
Radiologically = pulmonary hyperlucency caused by over-distended alveoli and diminished arterial flow characteristics.
Caused by:
RSV
Mycoplasma
Influenza virus
Staphyloccal and strep infections
Lung grow by progressive alveolarization of 2-8 years of life, after that growth is by hyper-expanding existing alveoli.
How do you manage this patient iwth bronchiolitis?
1) General Measures
Stop Smoking
Nutritional intake and supplement
Imms for influenza and pneumococcus
Confirm immunity to measles, pertussis and rubella
LTOT in advanced cases
MDT in CF (all aspects of dx)
2) Abx
Oral, parental or nebulized antibiotics (depending on clinical situation)
Nebulized tobramycin for pseudomonas aerguinosa infections in CF
3) Postural drainage and physio
Postural drainage with percussion and vibration
Fltter devices and pneumatic compression to helpp
Nebulized saline and mucolytics
Good hydration (reduce viscosity secretions)
Nebulized recombinant human dnase in CF
4) Bronchodilator therapy
5) Anti-inflammatory
IHS or Oral CS (only if have COPD/Asthma/ABPA)
6) Surgery
Surgical resection
Bronchial artery embolization for massive haemoptysis
FB or tumour removal
Lung transplant in patients with CF.
