Flashcards in Obstructive Airway Disease Deck (112)
what are the 3 conditions which fit into obstructive airway syndrome?
what is COPD/asthma overlap syndromes?
(generally smokers) with features of both asthma and COPD aka COPD with reversibility
what are the 3 parts of 'the asthma triad'?
reversible airflow obstruction
what is the dynamic progression of asthma?
2. chronic airway inflammation
3. airway remodelling
what is involved in the bronchoconstriction stage of asthma?
what is involved in the chronic airway inflammation stage of asthma?
exacerbations and airway hyper-reactivity
what is involved in the airway remodeling stage of asthma?
fixed airway obstruction
what are the 3 hallmarks of airway remodeling?
1. thickening of basement membrane
2. collagen deposition in submucosa
3. hypertrophy of smooth musce
what are the main type of immune cell infiltrate in asthma?
what are the 7 key features of the clinical syndrome of asthma/.
1. episodic symptoms and signs
3. non productive cough, wheeze
5. diurinal variability in episodes
6. associated atopy
7. family history of asthm
what is wheezing in asthma due to?
turbulent airflow in bronchioles
in an asthmatic patient what is the forced expiratory ratio?
FEV1/FVC below 75%
what is a bronchial challenge test?
a method of diagnosis asthma where the patient breathes in either nebulised methacholine (muscarinic agonist) or histamine and the resultant narrowing of airways is detected by spirometry.
how can you tell the difference between a patient without asthma and a patient with asthma on a bronchial challenge test?
patient with asthma will react to much lower doses of the nebulised spasmogens/bronchoconstrictors due to hyperreactivity of the airways
describe the diurnal variability in asthmatic episodes.
increased episodes in the morning morning
(PEFR markedly lower at this times)
how can use use a bronchial challenge test to distinguish between COPD and asthma?
by repeating bronchial challenge test after administration of salbutamol. if there is a reversibility to inhaled salbutamol >15%: asthma
what are the 3 factors involved in the development of obstruction and ongoing disease progression of COPD?
and what are they all caused by?
mucociliary dysfunction inflammation
caused by noxious particles or gases eg smoking
what are the 2 major symtpoms of COPD
what are the 2 major characteristics of the COPD?
reduced lung function
what is the main pathology behind emphysema?
disrupted alveolar attachments
what is the main immune cell involved in the infiltrate within airways in COPD?
what is the main pathology behind chronic bronchitis?
what causes emphysema and chronic bronchitis to occur?
proteases released from stimulated neutrophils causing proteolysis
what are the 4 features of chronic bronchitis?
chronic neutrophilic inflammation
smooth muscle spasm and hypertrophy
what are the 4 features of emphysema?
impaired gas exchange
loss of bronchial support
usually there are protease inhibitors which regulate the proteases produced by stimulated neutrophils, in COPD what happens to these protease inhibitors?
down-regulation causing increase proteolysis
what is the genetic element to acquiring COPD?
deficiency of protease inhibitors
what 3 things must you assess during the assessment of COPD?
assess degree of airflow limitation using spirometry
assess risk of exacerbations
what is an indicator of high risk COPD?
2 + exacerbations in 1 year
FEV1/FVC below 50%