COPD & Bronchiectasis (12/7/16) - Hussain Flashcards Preview

M2 Pulmonary > COPD & Bronchiectasis (12/7/16) - Hussain > Flashcards

Flashcards in COPD & Bronchiectasis (12/7/16) - Hussain Deck (13)
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1
Q

What is bronchiectasis?

A

Permanent abnormal dilatation of bronchioles and bronchi → loss of airway tone results in air trapping

2
Q

What is bronchiectasis due to?

Causes (5)?

A

Due to necrotizing inflammation with damage to airway walls. Causes include:

  • Cystic fibrosis (thick secretions → mucus plug → inflammation)
  • Kartagener syndrome → inherited defect of dynein arm (necessary for ciliary movement)
    • Associated with sinusitis, infertility (poor motility of sperm), situs inversus (position of major organs reversed)
    • Don’t have cilia to pump mucus out of lungs
  • Tumor of foreign body → inc. risk of infection
  • Necrotizing infection
  • Allergic bronchopulmonary aspergillosis → hypersensitivity rxn to Aspergillus → chronic inflammatory damage
    • Usually seen in individuals w asthma or CF
3
Q

Clinical features

A
  • Cough (b/c of mucus trapping)
  • Dyspnea
  • Foul-smelling sputum (loaded w inflammatory junk)
4
Q

Complications

A
  • Hypoxemia w/ cor pulmonale and secondary (AA) amyloidosis
    • Deposition of misfolded protein
    • Chronic inflammation end product SAA converted to AA and deposited as amyloid
5
Q

Types of COPD

A
  • Chronic bronchitis
  • Emphysema
  • Asthma
  • Bronchiectasis
6
Q

Chronic Bronchitis

Characterization

A
  • Chronic productive cough - lasts at least 3 mo. over 2+ years
  • Highly associated with smoking
  • Diffuse process
  • Characterized by hypertrophy of bronchial mucinous glands
    • ​Smoking inc. production/thickness of mucus glands relative to bronchial wall thickness
7
Q

Chronic Bronchitis

Clinical features

A
  • Productive cough due to excessive mucus production
    • Difficulty clearing secretions b/c of poor ciliary function
  • Cyanosis (“blue bloaters”)
    • Mucus plugs trap CO2
      • Inc PaCO2 and dec. PaO2
  • Inc. risk of infection and cor pulmonale

Trapped <——- mucus in lumen ———-> cough

8
Q

What usually exacerbates chronic bronchitis?

A

Viral infections

9
Q

Emphysema

Characterization

A
  • Destruction of alveolar air sacs
    • Loss of elastic recoil and collapse of airways during exhalation
    • RESULT: obstruction and air trapping
10
Q

Emphysema

Cause

A

Imbalance of proteases and antiproteases

  • Inflammation in lung normally leads to release of proteases by neutrophils and macrophages
  • alpha1-antitrypsin (A1AT) neutralizes proteases
  • Excessive inflammation OR lack of A1AT → destruction of alveolar air sacs
11
Q

Most common cause of emphysema?

A

Smoking

Pollutants in smoke → excessive inflammation and protease-mediated damage

Result: centriacinar emphysema most severe in upper lobes

12
Q

A1AT deficiency

A
  • Rare cause of emphysema
    • Lack of antiprotease leaves air sacs vulnerable to protease-mediated damage
  • Results in panacinar emphysema most severe in LOWER LOBES
  • Liver cirrhosis may also be present
    • A1AT deficiency due to misfolding of mutated protein
    • Mutant A1AT accumulates in ER of hepatocytes → liver damage
    • Biopsy = pink, PAS-positive globules in hepatocytes
13
Q

Emphysema

Clinical features

A
  • Dyspnea and cough w MINIMUAL SPUTUM (NOT chronic bronchitis)
  • Prolonged expiration w/ pursed lips (“pink puffer”)
    • ​Back pressure from pursed lips will force walls open
  • Weight loss (all their calories are going into breathing)
  • Inc. A-P diameter of chest (‘barrel chest’)
  • Late complications:
    • Hypoxemia (due to destruction of capilllaries in alveolar sac)
      • Late b/ body will gravitate towards good lung units until there is no more
      • Inc ventilation of poorly perfused lung units (high V/Q ratio)
    • cor pulmonale