Pathology of Obstructive Lung Disease Flashcards
What is localised obstruction?
Obstruction of a large airway
What can localised obstruction be caused by?
Lung cancer
Inhaled foreign bodies
Chronic scarring diseases like bronchiectasis and secondary tuberculosis
What is generalised small airway obstruction?
Bronchiolar obstruction
Other names for COPD include
- Chronic Obstructive Airways Disease
- Chronic Obstructive Lung Disease
How rare is it for patients to have only chronic bronchitis or only emphysema?
Very rare
Aside from spirometry, what can obstructive lung disease be demonstrated by?
Peak expiratory flow rate (PEFR)
What is the normal peak expiratory flow rate?
400-600L/min
What is the normal range, moderate fail and marked fail of PEFR?
80-100% of best value is normal 50-80% is moderate fail <50% is marked fail
How does obstructive lung disease affect spirometry and peak expiratory flow rate?
Always airflow limitations
Peak expiratory flow rate is reduced
FEV1 is reduced
FVC may be reduced
FEV1 is less than 70% of FVC
What is bronchial asthma?
Type 1 hypersensitivity in the airways
What is bronchial asthma mediated by?
Immunologically mediated, leading to the degranulation of mast cells that releases a number of chemical factors
What are the 2 main effects of the chemical factors released by mast cell granules?
- induce inflammation by attracting a number of inflammatory cell types into the airway leading to swelling and edema within the bronchial mucosa
- chemicals which have a direct effect on the bronchial smooth muscle leads to airway inflammation and constriction
What is important about bronchial asthma?
Reversible airway obstruction either spontaneously or as a result of medical intervention
What can bronchial smooth muscle contraction and inflammation be modified by?
Drugs
Do asthmatics have airflow limitations all the time?
No, only during an asthma attack
What is the aetiology of chronic bronchitis and emphysema?
Smoking
Atmospheric pollution
Occupational dust
Alpha-1-antitrypsin deficiency
Effects of age and susceptibility
What is Alpha-1-antiprotease(antitrypsin) deficiency?
A rare inherited disease where the patient suffers from a deficiency in antitrypsin or antiprotease enzymes causing emphysema alone
Do more men or woman have COPD and why?
Men because they smoke more
What is chronic bronchitis?
Cough production of sputum most days in at least 3 consecutive months for 2 or more consecutive years (excludes TB, bronchiectasis)
What is chronic bronchitis easily confused with?
Chronic bronchial asthma
Complicated chronic bronchitis refers to
when sputum becomes infected, mucopurulent, yellow or green during an acute infection
What is morphological?
Size, shape and structure of a given organ
What are morphological changes in the large airways due to chronic bronchitis?
Mucous gland hyperplasia
Goblet cell hyperplasia
Inflammation and fibrosis is a minor component
What is hyperplasia?
Enlargement of an organ or tissue caused by an increase in the reproductive rate of its cells
What are morphological changes in the small airways due to chronic bronchitis?
Goblet cells appear
Inflammation and fibrosis in long-standing disease
What is emphysema?
Increase beyond the normal in the size of airspaces distal to the terminal bronchiole arising either from dilation of from destruction of their walls and without obvious fibrosis
What is an acinus?
gas exchange tissue part of the lung defined by everything distal to the terminal bronchiole
What is the size of the normal acinus duct?
1-2cm, cannot see where one ends and where another begins
What are the different forms of emphysema?
Centriacinar
Panacinar
Periacinar
Scar ‘irregular’
Bullous emphysema