Obstructive Airway Diseases Flashcards
What is chronic bronchitis and emphysema better now as?
COPD (COAD or COLD)
What factors determine predicted FVC?
Sex, age and height
Besides FEV1/FVC - how else may obstructive lung disease be demonstrated?
Peak Expiratory Flow Rate (PEFR)
What is the normal value of PEFR?
400-600litres/min
What is considered a marked fall in PEFR value?
<50% of best
How can FEV1/FVC demonstrate obstructive lung disease?
FEV1/FVC value < 0.7
What are the common aetiologies of chronic bronchitis and emphysema?
SMOKING (just don’t do it kids - not cool)
Atmospheric pollution
Rarely: Alpha-1 antiprotease (antitrypsin) deficiency is a rare cause of emphysema (not CB)
What is the clinical definition of chronic bronchitis?
Cough productive of sputum most days in at least 3 consecutive months for 2 or more consecutive years
Why the complicated time constraints of the clinical definition of chronic bronchitis?
It excludes other lung diseases such as TB, Bronchiectasis and chronic bronchial asthma
What qualifies complicated chronic bronchitis?
When mucopurulent (acute infective exacerbation) occurs or when FEV1 falls
What are the morphological changes that occur in the large airways with chronic bronchitis?
Mucous gland hyperplasia
Goblet cell hyperplasia
(Inflammation and fibrosis to small extent)
What are the morphological changes that occur in the small airways with chronic bronchitis?
Goblet cells appear
Inflammation and fibrosis in long standing disease
What the pathological definition of emphysema?
Increase beyond the normal size of airspaces distal to the terminal bronchiole arising either from dilatation or or destruction of their walls without obvious fibrosis
What are the five forms of emphysema?
Centriacinar Panacinar Periacinar Scar/Irregular Bullous emphysema
What are the clinical features of centriacinar emphysema?
Emphysematous tissue around the terminal bronchiole
How is panacinar emphysema characterised?
Dilatation of alveoli - massively destructive
What are the clinical features of periacinar emphysema?
Emphysematous tissue just under pleural membrane
What is a bulla?
An emphysematous space greater than 1 cm
Bulla are not much to worry about - what happens when they burst though?
Spontaneous pneumothorax
Describe the common pathogenesis of emphysema?
Smoking leads to an Alpha-1 antiprotenase (antitrypsin) deficiency - this upsets the elastin framework in alveolar tissue
What do pharmacological treatments for COPD tackle?
Smooth muscle tone and inflammation in the small airways
What effect does a reduction in the elastin framework of the alveoli have?
Loss of alveolar attachments responsible for keeping bronchioles open
What is chronic (hypoxic) cor pulmonale?
Hypertrophy of the right ventricle resulting from disease affecting the function and/or the structure of the lung
What factors contribute to pulmonary hypertension?
Pulmonary vasoconstriction Pulmonary arterioles - muscular hypertrophy and intimal fibrosis (fibrosis of inner most endothelium) Loss of capillary bed Secondary polycythaemia (increased [RBC] leads to increased blood viscosity)
