COPD Flashcards
Define COPD
COPD is a progressive disorder characterised by airway obstruction with little or no reversibility, associated w/ an abnormal inflammatory response (typically to cigarette smoke)
What conditions comprise COPD?
Chronic Bronchitis (inc airway resistance)
Bronchiolitis
Emphysema (dec outflow pressure)
What is Chronic Bronchitis?
Inflammation of bronchi –> mucus production
Cough & sputum production on most days for 3/12 of 2 successive years
What is Emphysema?
Enlarged air spaces distal to terminal bronchioles w/ destruction of alveolar walls but no fibrosis
Breathlessness
What is bronchiolitis?
Inflammation of airways <2mm in diameter –> scarring and narrowing
-first change in COPD
What are the pathological features of chronic bronchitis?
Hypertrophy/Hyperplasia of mucous glands
Frequent LRTIs - 2o inflammation, sq metaplasia
What is the Reid index?
Ratio of gland:wall thickness in bronchus
What causes alveolar destruction in emphysema?
Extracellular proteases (inflam cells)
What is the most common form of emphysema?
Centrilobular emphysema
- changes limited to central part of lobule
- normal alveoli elswhere
What is panacinar emphysema?
Destruction/distension of whole lobule
-more common in a1-antitryspin deficiency
What are the risk factors for COPD?
Cigarette smoke exposure Occupational dust exposure a1-antritrypsin deficiency Recurrent chest infections in childhood Low socioeconomic status Asthma/atopy
How does COPD present?
Productive morning cough Increased LRTIs Progressive dyspnoea w/ wheeze Resp failure RHF (cor pulmonale)
What are the signs of COPD?
Mild - widespread wheeze
Severe
- tachypnoea, cyanosis, flapping tremor
- hyperinflation, intercostal recession, resp distress
- raised JVP, poor chest exapnsion, hyper-resonant chest
- decreased breath sounds, prolonged exp phase, polyphonic wheeze
NEVER CLUBBING
What are the common complications of COPD?
Acute exacerbations Polycythaemia Resp failure Cor pulmonale Pneumothorax Lung carcinoma
What are the two main groups of COPD pts?
Blue bloaters
Pink puffers
What are blue bloaters?
Pts w/ severe COPD who are insensitive to CO2
Rely on hypxoic drive to stimulate resp effort
What are the features of blue bloaters?
Not breathless
Cyanosed & oedematous
What ABG features are common in blue bloaters?
Type 2 resp failure
What is the key management difference in blue bloaters?
Give O2 w/ care, can compromise resp drive
What are pink puffers?
Pts sensitive to CO2
What are the features of pink puffers?
Tachypnoeic
Tachycardic
Breathless but not cyanosed
Can progress to Type 1 resp failure
What investigations are appropriate in suspected COPD?
Clinical diagnosis if typical sx in pt >35 w/ risk factor Post-bronchodilator spirometry CXR FBC (anaemia, polycythaemia) Sputum culture ECG (RV hypetrophy) ABG DLCO
How can spirometry be used to stage COPD?
Stage 1 (mild) - FEV1 <80% predicted Stage 2 (mod) - FEV1 50-79% predicted Stage 3 (sev) - FEV1 30-49% predicted Stage 4 (v. sev) - FEV1 <30% predicted
What features on CXR are suggestive of COPD?
Hyperinflation (6ant, 10post) Flattened hemidiaphragms Large central pulmonary aa Reduced periph vasc markings Bullae
