Session 6- Obstructive Lung Diseases Flashcards Preview

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Flashcards in Session 6- Obstructive Lung Diseases Deck (26)
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1
Q

what is asthma

A

a chronic inflammatory disorder of the airways characterised by intermittent airway obstruction.
Obstruction of the airways- reversible

2
Q

what is the difference between the obstruction inn COPD and asthma

A

in asthma its reversible- improves with bronchodilators

3
Q

Pathophysiology of asthma

A

Macrophages process and present antigens to t lymphocytes

This activates T cells with Th2 cells being preferentially activated

Th2 cells release cytokines which attract and activate inflammatory cells

Th2 cells activate B cells which produce IgE

Exposure to antigen results in a 2 phase response consisting of an intermediate response followed by a late phase response

4
Q

What inflammatory cells are involved in asthma

A

Th2 cells aka Cd4+

5
Q

What is The immediate response and what causes it

A

Type 1 hypersensitivity

Caused by an interaction of the allergen and specific IgE antibodies leading to mast cells degranulation and release of mediators

6
Q

What does type 1 hypersensitivity lead to

A

Bronchial smooth muscle contraction and bronchoconstriction

7
Q

What is the late phase response

A

Type 4 hypersensitivity

Involves inflammatory cells, including eosinophils, mast cells, lymphocytes and neutrophils.

Cause airway inflammation

8
Q

What do the eosinophils release and what does it cause

A

Leukotriene C4 and other mediators which are toxic to epithelial cells causing shedding of the cells

9
Q

How does the inflammation affect the airways

A

Mucosal swelling

Thickening o bronchial walls- infiltrated by inflammatory cells

Mucus over production- dry or productive white sputum

Smooth muscle contraction

Epithelium shed and incorporated into mucus

10
Q

What does long term asthma often result in

A

Airway remodelling

  • hypertrophy and hyperplasia do smooth muscle
  • hypertrophy of mucus glands
  • thickening of basement membrane
11
Q

Effects of airways narrowing during investigation

A

Wheezing
Obstructive pattern on spirometry
Air trapping with increased residual volume
-increased FRC

12
Q

what type of resp failure can unmanaged mild to moderate asthma lead to

A

Airway narrowing leads to V/Q mismatch in affected alveoli area

Hyperventilating of better ventilated areas can’t compensate for the hypoxaemia but can for co2 retention = type 1 Resp failure

13
Q

In severe cases of asthma what type of Resp failure does it show

A

Type 2 - blockage of airways and exhaustion limits the amount of co2 which can be breathed out

14
Q

Treatment of asthma

A

Patient education
Drug treatment- bronchodilators and steroids
Up to date vaccinations

15
Q

how can you differentiate between asthma and COPD on spirometry

A

Spirometry- when you give spirometers to an asthma patient their FEV will increase when you give bronchodilatprs it needs to increase by 12% in order to be asthma

16
Q

what is the triad of characteristics of asthma

A

Triad of characteristics

  • muscle constraction
  • airway inflammation
  • increased secretions
17
Q

how does asthma present

A
cough
wheeze
breathlessness
chest tightness 
atopy
18
Q

prepipating factors for an asthma attack

A
allergens 
dust
cigarette smoke
cold weather
exercise
infections
aerosols
19
Q

what is difference between the coughs in COPD vs Asthma

A

COPD- Productive

Asthma- Dry

20
Q

what pattern is seen on a spiromter in COPD and asthma

A

obstructive

21
Q

what pattern is seen on a spiromter in COPD and asthma

A

obstructive

22
Q

reversibility of COPD

A

poor- no improvement with bronchodilator

23
Q

what is step 1 in asthma management - treatment

A

short acting beta-2-agonist

  • bronchial smooth muscle relaxation
  • binds to b2 receptor activates Galpha s which dissociated and binds to adenylyl cyclase converting ATP to cAMP which activates protein kinase A

Inhaled corticosteroid
-anti inflammatory

24
Q

what is step 2 in asthma management

A

combined inhaler
-long acting beta-2-agonist- bronchial smooth muscle relaxation

-anti-inflammatory

25
Q

what is step 3 in asthma management

A
  • can increase dose of inhaled corticosteroid

- add a leukotriene receptor antagonist

26
Q

what are rhonchi

A

“large airway sounds,” are continuous gurgling or bubbling sounds typically heard during both inhalation and exhalation. These sounds are caused by movement of fluid and secretions in larger airways