Mx of COPD Flashcards
Is COPD reversible?
Nope
Describe the basic pathology of COPD and smoking
Paralysis of cilia + Direct mucosal toxicity
↓
Airway inflammation + Mucus gland hyperplasia
↓
Airway oedema + mucus hypersecretion
↓
Chronic Bronchitis
↑ alveolar macrophages
→ Release of proteases
↓
Destruction of collagen & elastase
↓
Damage to alveolar wall
↓
Emphysema
Define chronic bronchitis
Cough productive of sputum on most days for at least 3 months for 2 consecutive years
define emphysema
Abnormal permanent enlargement of distal airspaces accompanied by destruction of their walls without obvious fibrosis
describe the pathology of emphysema
alveolar wall destruction
enlargement of distal airspaces
loss of lung elastic recoil
signs and symptoms of chronic bronchitis
cough sputum production dyspnoea on exertion wheeze hypoxaemia hyperinflation pursed lip breathing central cyanosis flapping tremor cor pulmonale weight loss
signs and symptoms of emphysema
progressive dyspnoea
decreased breath sounds
hypoxaemia
how do we measure the extent of emphysema
CT scanning
Pulmonary function testing: Gas transfer reduces
(TLCOc/KCOc), increased residual volume
what does normal lung look like on CT
grey, no black spaces
why does hyperinflation make it hard to breathe?
Residual volume- gas trapping, causes barrel shaped chest as you don’t breathe out all the air your breathed in. diaphragm can’t move in the normal way
what causes airway obstruction in COPD
increased resistance to airflow caused by airway narrowing
what causes the airway narrowing in COPD
Combination of:
-Large airway disease
Mucosal inflammation → bronchoconstriction
Intra-luminal mucus
Smooth muscle hypertrophy
-Small airway disease
above
Loss of outward traction on airways due to alveolar destruction
Due to combined effects of chronic bronchitis + emphysema
How does emphysema cause airway obstruction
Alveoli act as springs to hold the airway open, mainly in expiration, pulling it open
In emphysema: destruction of alveolar walls leads to fewer connections in the airway, fewer springs holding the airway open.
how do we measure airway obstruction in COPD?
spirometry- FEV1, FVC, FEV1/FVC ratio
what spirometry results indicate obstructive disease
↓ FEV1 (<70 % pred) & FEV1/FVC < 0.7 indicates obstructive disease
