L7 18 Mar 2019 Flashcards
Asthma
1
Q
What are the three types of chronic obstructive pulmonary disease?
A
- emphysema: alveolar wall destruction, over inflation
- chronic bronchitis: productive cough, airway inflammation
- asthma: reversible obstruction
2
Q
emphysema
A
- irreversible enlargement of airspaces, distal to terminal bronchiole
- most smokers suffer from this
- too much coughing –> elasticity is lost, also tar deposit
3
Q
chronic bronchitis
A
- persistent cough with sputum production for at least 3 mths in two consecutive years; may progress to COPD and may overlap with emphysema –> hypersecretion of mucus and if persistene marked increase in goblet cells in small airways
- therapy: mucolytics
4
Q
asthma
A
- chronic disorder of airways, usually caused by immunological reaction, marked by bronchoconstriction
- increased airway sensitivity to various stimuli
- inflammation of bronchial walls
- increased mucus secretion
- bronchial hyperresponsiveness
5
Q
symptoms of asthma
A
- recurrent episodes of wheezing
- breathlessness
- chest tightness
- dry cough
6
Q
four types of asthma
A
- atopic asthma
- non-atopic asthma
- drug-induced asthma
- occupational asthma
7
Q
atopic asthma
A
- triggered by environmental allergens (dusts, pollens, roach or animal dander, foods)
- type I IgEmediated hypersensitivity reaction
- hereditary, and also common type of asthma
8
Q
non-atopic asthma
A
typically virus-induced inflammation lowers threshold to irritants
9
Q
drug-induced asthma
A
salicylate (aspirin)-induced is a typical example
10
Q
occupational asthma
A
exposure to fumes (plastics, organic solvents, chemical dusts)
11
Q
common precipitating factors in aetiology of asthma
A
- common cold/other viral infections, sinusitis, bronchitis/bronchiolitis
- pollens (weeds, grasses, trees), dusts, feathers, animal fur, furniture stuffing, fungal spores
- fumes (petrol, paint, tobacco, industrial chemicals), cold air, air pollutants
- laughter, physical exertion, psychological stress, drugs
12
Q
how is asthma diagnosed?
A
- perisistent cough
- wheezing (via stethoscope)
- shortness of breath - stethoscope
- spirometry - most common lung function test
13
Q
complication of diagnosis(/misdiagnosis) with asthma
A
- anaphylaxis: need epinephrine
- pulmonary embolism: need blood thinning - warfarin
14
Q
spirometry
A
measures FEV (forced expiratory volume)
- not safe to do spirometry with methacoline and exercise challenges
15
Q
pathologenesis of atopic asthma
A
Type I IgE-mediated hypersensitivity immediate reaction
- alleren stimulates TH2 response
- class switching from IgG (B cells) to IgE
- IgE binds to Fc receptors on mast cells
- subsequent exposure to allergen = mast cell activation
16
Q
atopic asthma pathologenesis
mast cell mediators
A
- ECF: eosinophil chemotactic factor
- NCF: neutrophil chemotactic factor
- PAF: platelet activating factor
late phase reaction = chemotactic factors + leukotrines
