COPD

Question 1

def

Answer 1

chronic progressive lung disorder characterized by airflow obstruction with either or both:
1 chronic bronchitis
-chronic cough & sputum for >3months per year over 2 consecutive years
2 emphysema
-permanent destructive enlargement of air spaces distal to terminal bronchioles

Question 2

aetiology

Answer 2

bronchial & alveolar damage due to environmental toxins (cigarette smoke)
in young patients or non-smokers a1-antitrypsin deficiency should be considered
COPD overlaps & may co-present with asthma

Question 3

aetiology of chronic bronchitis

Answer 3

narrowing of airways due to bronchiole inflammation & bronchi with mucosal oedema, mucous hypersecretion

Question 4

aetiology of emphysema

Answer 4

destruction & enlargement of alveoli
this results in loss of elastic traction which keeps small airways open in expiration
progressively larger spaces develop called bullae (diameter >1cm)

Question 5

epi

Answer 5

very common in middle age or later with smokers

more common in males but likely to change with increased female smokers

Question 6

history

Answer 6

chronic cough & sputum production
breathlessness, wheeze
decreased exercise tolerance`

Question 7

examination

Answer 7

INSPECTION
-respiratory distress
-use of accessory muscles
-barrel shaped overinflated chest & decreased cricosternal distance
-cyanosis
PERCUSSION
-hyper-resonant chst
-loss of liver & cardiac dullness
AUSCULTATION
-quiet breath sounds
-prolonged expiration
-wheeze

Question 8

examination findings in CO2 retention

Answer 8

bounding pulse
warm peripheries
flapping tremor of hands (asterixis)
signs of RHF (raised JVP, ankle oedema)

Question 9

investigations

Answer 9

1 spirometry & pulmonary function tests
-obstructive picture as reflected by decreased PEFR, decreased FEV1: FVC ratio, increased lung volumes
2 CXR
-may show hyperinflation (>6 ribs visible anteriorly, flat hemidiaphragms)
-elongated cardiac silhouette
3 blood
-FBC (increased Hb & PCV due to secondary polycythemia)
4 ABG
-may show hypoxia, and normal or increased PaCO2
5 ECG for cor pulmonale
6 sputum & cultures in acute exacerbations for treatment
7 consider a1-antitrypsin levels in young or non-smokers

Question 10

what are the mild, moderate, and severe gradings for FEV1: FVC ratio

Answer 10

mild 60-80%
moderate 40-60%
severe <40%

Question 11

what indicates alveolar destruction in COPD

Answer 11

decreased carbon monoxide gas transfer coefficient

Question 12

management of COPD

Answer 12

1 stop smoking
2 bronchodilators
-SABA (salbutamol) & anticholinergics (ipratropium) by inhalers/nebulisers
-LABA if >2 exacerbations PA
3 steroids
-inhaled beclometasone with FEV1 <50% predicted or >2 exacerbations PA
4 pulmonary rehabilitation
5 oxygen therapy for those who stop smoking
indications
-PaO2 <7.3kPa on air during period of clinical stability
-PaO2 7.3-8kPa & signs of secondary polycythaemia, nocturnal hypoxaemia, peripheral oedema, pulmonary HTN

Question 13

management of acute infective exacerbations of COPD

Answer 13

1 24% O2 via a non-variable Venturi mask
2 increase slowly if no hypercapnia & still hypoxic
3 corticosteroids
4 antibiotics
5 respiratory physiotherapy is essential to clear sputum
6 prevention of infective exacerbations by pneumococcal & influenza vaccination

Question 14

complications

Answer 14

acute respiratory failure
infections (streptococcus pneumonia, haemophilus influenzae)
pulmonary HTN & RHF
pneumothorax from bullae rupture

Question 15

prognosis

Answer 15

high morbidity
3yr survival of 90% at <60yrs & FEV1 >50% predicted
3yr survival of 75% at >60yrs & FEV1<50% predicted