Session 6- Obstructive Lung Diseases

Question 1

what is asthma

Answer 1

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

Question 2

what is the difference between the obstruction inn COPD and asthma

Answer 2

in asthma its reversible- improves with bronchodilators

Question 3

Pathophysiology of asthma

Answer 3

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

Question 4

What inflammatory cells are involved in asthma

Answer 4

Th2 cells aka Cd4+

Question 5

What is The immediate response and what causes it

Answer 5

Type 1 hypersensitivity

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

Question 6

What does type 1 hypersensitivity lead to

Answer 6

Bronchial smooth muscle contraction and bronchoconstriction

Question 7

What is the late phase response

Answer 7

Type 4 hypersensitivity

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

Cause airway inflammation

Question 8

What do the eosinophils release and what does it cause

Answer 8

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

Question 9

How does the inflammation affect the airways

Answer 9

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

Question 10

What does long term asthma often result in

Answer 10

Airway remodelling

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

Question 11

Effects of airways narrowing during investigation

Answer 11

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

Question 12

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

Answer 12

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

Question 13

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

Answer 13

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

Question 14

Treatment of asthma

Answer 14

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

Question 15

how can you differentiate between asthma and COPD on spirometry

Answer 15

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

Question 16

what is the triad of characteristics of asthma

Answer 16

Triad of characteristics

• muscle constraction
• airway inflammation
• increased secretions

Question 17

how does asthma present

Answer 17

cough
wheeze
breathlessness
chest tightness 
atopy

Question 18

prepipating factors for an asthma attack

Answer 18

allergens 
dust
cigarette smoke
cold weather
exercise
infections
aerosols

Question 19

what is difference between the coughs in COPD vs Asthma

Answer 19

COPD- Productive

Asthma- Dry

Question 20

what pattern is seen on a spiromter in COPD and asthma

Answer 20

obstructive

Question 21

what pattern is seen on a spiromter in COPD and asthma

Answer 21

obstructive

Question 22

reversibility of COPD

Answer 22

poor- no improvement with bronchodilator

Question 23

what is step 1 in asthma management - treatment

Answer 23

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

Question 24

what is step 2 in asthma management

Answer 24

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

-anti-inflammatory

Question 25

what is step 3 in asthma management

Answer 25

• can increase dose of inhaled corticosteroid

- add a leukotriene receptor antagonist

Question 26

what are rhonchi

Answer 26

“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