Lecture 12: Bronchiectasis Flashcards Preview

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Flashcards in Lecture 12: Bronchiectasis Deck (45)
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1
Q

Bronchiectasis: definition

A

Permanent, abnormal dilatation of the bronchi

2
Q

Bronchiectasis: hypothesis

A

External insult –> respiratory tract damage –> infection –> inflammation –> damage (repeat)

3
Q

What is the etiology of the initial external insult? (5)

A

Infection, aspiration, autoimmune, toxic inhalation, radiation

4
Q

Bronchiectasis: pathophysiology

A

Once airways are irreversibly dilated, defense mechanisms are disturbed (no cilia, bacterial colonization, abnormal collapsible airways)

5
Q

In bronchiectasis, small airways are often?

A

Inflamed, obstructed

6
Q

Bronchiectasis: infections causes

A

Measles/pertussis, TB, MAC, allergic bronchopulonary aspergillosis

7
Q

But recurrent infections are not common, what can cause this? (3 main causes and details)

A

Airway obstruction (tumor, foreign body, thick mucus); impaired mucous clearance (CF, primary ciliary dyskinesia); defect in host defenses (humoral/cellular immunity deficiency)

8
Q

Patterns of bronchiectasis (3)

A

Cylindrical: smooth dilation; varicose: focal narrowings along dilated bronchus, cystic: progressive dilation of bronchus which terminates in cysts or saccules

9
Q

Do you only get one bronchiectasis pattern per patient?

A

Nope–they can have all three!

10
Q

Most prominent symptom of bronchiectasis

A

Cough w/ copious sputum

11
Q

Why can a patient with bronchiectasis get hemoptysis?

A

Result of inflammation –> increased bronchial blood supply –> erosion/mechanical trauma –> hemoptysis

12
Q

Bronchiectasis: physical exam

A

May have wheezing/ronchi/crackles, clubbing

13
Q

Bronchiectasis: gas exchange

A

May be normal if disease is still localized

14
Q

Bronchiectasis: pulmonary function test

A

Normal, or obstructive ventilatory defect w/ air trapping

15
Q

Bronchiectasis: treatment (3)

A

Antibiotics, bronchopulmonary drainage, bronchodilators

16
Q

When are bronchodilators indicated?

A

W/ partially reversible co-existing airway obstruction

17
Q

Why would we want to do airway clearence techniques? What do these techniques do?

A

Because ciliary elevator isn’t working; loosen mucous via rubbing or vibration

18
Q

Why do we want to treat the hemoptysis in bronchiectasis? How do we treat?

A

It can be life-threatening via asphyxiation (block of gas exchange); electrical cauterization

19
Q

Cystic fibrosis is an _________ __________ genetic disorder

A

Autosomal recessive

20
Q

Describe CFTR

A

Epithelial Cl- channel regulatory domain

21
Q

CFTR function in different tissues

A

Sweat: salt but not volume absorbing; Airways: volume absorbing; Pancreas, intestine: volume-secreting

22
Q

In the lungs, how does cystic fibrosis affect?

A

Hyperabsorption of NaCl + water –> decreased ability for cilia to move –> decreased clearance AND bacterial adhesion

23
Q

How does CFTR gene affect Na+ channels when airway surface liquid volume is high?

A

CFTR gene keeps Na+ channel open to allow Na+ into cell –> negative EC gradient –> Cl- abosrbed; water follows

24
Q

How does CFTR gene affect Na+ channels when airway surface liquid volume is low?

A

CFTR gene closes Na+ channel –> positive EC gradient –> Cl- excreted –> water follows

25
Q

How does CFTR gene affet Na+ channels in someone w/ CF?

A

Na+ channel open always

26
Q

CFTR in pancreas. In CF?

A

CFTR needed to secrete HCO3- and water into pacreatic ducts; in CF –> viscous, acidic secretions –> retention of pancreatic enzymes –> tissue destruction

27
Q

CFTR in intestine. In CF?

A

CFTR needed for Cl- and water secretion; in CF –> instestinal epithelium fails to flush secreted mucins and other molecules from intestinal crypts –> dehydrated intraluminal contents

28
Q

CFTR in sweat glands. in CF?

A

F

29
Q

Class II mutation. What do we need to know?

A

Transcribe, translate, but misfolded and destroyed; most common = deltaF508 missense mutation w/ aa deletion

30
Q

Various CFTR mutations mean what?

A

Different organs can be affected to different degrees

31
Q

CF: pulmonary pathology

A

Thick, uncleared mucous plugs in bronchi –> pneumonitis, frank bronchiectasis, abscess formation

32
Q

Where does CF affect the lungs the most?

A

Bronchioles (which are plugged by secretons)

33
Q

CF: pathophysiology

A

Recurrent infection and bronchiectasis –> colonization with unusual bugs (pseudomonas, staph aureus) –> obstructive airway disease

34
Q

How does CF present neonatally?

A

10-20% during neonatal period (meconium ileus = obstruction)

35
Q

What would a CF childhood presentation look like?

A

Pancreatic insufficiency, recurrent bronchial infections

36
Q

Five CF pulmonary complications

A

Pneumothorax, hemoptysis, ABPA, pulmonary hypertension, respiratory failure

37
Q

Three classes of non-pulmonary CF complications

A
  1. GI: exocrine pancreatic insufficiency, obstruction, rectal prolapse; 2. Renal/endocrine: loss of salt –> hypovolemia; 3. GU: azoospermia
38
Q

Dx of CF

A

Clinical features plus abnormal sweat electrolytes, electrical potential differences, or gene

39
Q

Tx of CF

A

Diminish clinical consequences: antibiotics, bronchopulmonary drainage, bronchodilators

40
Q

How could we decrease secretion viscosity?

A

Inhale recombinant deoxyribonuclease or hypertonic saline (draws water onto airway surface)

41
Q

Newer therapies in CF are…

A

Mutation-specific

42
Q

Ivacaftor: function and the class it helps

A

Increases time activated CFTR channels at cell surface remain open (help Class III mutations)

43
Q

Lumacaftor: function and the class it helps and how it should be delivered

A

Partially corrects CFTR misfolding (helps Class II), give with Ivacaftor to help resulting Class III defect

44
Q

What is primary ciliary dyskinesia?

A

Heterogenous group of deficits involving the axoneme, spokes, or dynein arms, etc.; autosomal recessive

45
Q

Describe Kartagener’s syndrome and describe why

A

Characterized by bronchiectasis, sinusitis, and situs inversus; normal cilia determine position of internal organs during early embryological development –> embryos with PCD have 50% chance of developing situs inversus