Chronic Obstructive Pulmonary Disease

Question 1

What is the clinical definition of COPD?

Answer 1

Airway obstruction with little or no reversibility
- FEV1 <80% of predicted
- FEV1/FVC ratio <0.7
Includes chronic bronchitis and emphysema

Question 2

What are the risk factors for COPD?

Answer 2

Age >35
Smoking (passive/active)
Air pollution 
Chronic dyspnoea 
Sputum production

Question 3

What are the most common causes of COPD?

Answer 3

Tobacco consumption

Alpha-1 antitrypsin deficiency

Question 4

What is the clinical definition of chronic bronchitis?

Answer 4

Cough and sputum production on most days for three months of two successive years
Stopping smoking improves symptoms
No excess mortality if lung function hasn’t deteriorated yet

Question 5

What is the clinical definition of emphysema?

Answer 5

Enlarged air spaces distal to the terminal bronchial and destruction of the alveolar walls
Seen on CT but normally a clinical diagnosis

Question 6

What is a pink puffer?

Answer 6

Increased alveolar ventilation, near normal PaO2 and increased PaCO2
Breathless, but not cyanosed
May progress to type 1 respiraotyr failure

Question 7

What is a blue bloater?

Answer 7

Decreased alveolar ventilation, decreased PaO2 and increased PaCO2
Cyanosed but not breathless
May develop into cor pulmonale
Hypoxic drive - careful with supplemental oxygenation

Question 8

What are the clinical features of COPD?

Answer 8

Cough
Sputum
Dyspnoea
Wheeze
Tachypnoea
Use of accessory muscles for respiration 
Hyperinflation 
Decreased cricosternal distance 
Decreased expansion 
Resonant or hyper-resonant percussive note
Quiet breath sounds 
Cyanosis

Question 9

What are the complications of COPD?

Answer 9

Acute exacerbation +/- infections
Polycythaemia 
Cor pulmonale (oedema + raised JVP)
Respiratory failure
Pneumothorax
Lung carcinoma

Question 10

What investigations would you do to diagnosis COPD (non-acute attack)?

Answer 10

Blood tests
- FBC (check for alpha-1 antitrypsin deficiency - increased haemoglobin and PCV)
- ABG (decreased PaO2 and increased PaCO2 in advanced disease)
Chest X-Ray
CT
ECG - might show right atrial and ventricular hypertrophy as large P waves (cor pulmonale)

Question 11

What changes would you expect on Chest X-Ray in COPD?

Answer 11

Hyperinflation
Flat hemidiaphragm 
Large central pulmonary arteries 
Decreased peripheral vascular markings 
Bullae

Question 12

What changes would you expect to see on CT in COPD?

Answer 12

Bronchial wall thickening
Scarring
Air space enlargement

Question 13

What would spirometry show in COPD?

Answer 13

FEV1 <80% of predicted 
FEV1:FVC ratio <0.7
Increased total lung volume
Increased reserve volume 
Decreased DLCO in emphysema

Question 14

What severity of COPD is associated with FEV1 percentages?

Answer 14

Mild > 80%
Moderate 50-79%
Severe 30-50%
Very severe <30%

Question 15

What are the indications for long term oxygen therapy?

Answer 15

PaO2 <7.3kPa (<8kPa if patient has polycythaemia, oedema, hypoxaemia or pulmonary hypertension)
FEV1 30-49% of predicated
Cyanotic

Question 16

What are the stages of pharmaceutical management for chronic COPD?

Answer 16

Stage 1
- initiate a SABA/SAMA 
Stage 2 (FEV1 <50%)
- introduce LAMA 
- or LABA and ICS in a combined inhaler
Stage 2 (FEV1 >50%)
- introduce LAMA
- or introduce LABA
Stage 3
- introduce LABA and ICS in combined inhaler if not already on it 
- last step is LAMA and LABA/ICS all at once

Question 17

What are the non-pharmaceutical options for chronic COPD management?

Answer 17

Exercise training - symptom control
Diet - promotes weight gain
Surgery 
- bullectomy if large emphysemous bullae
- lung transplant if end stage emphysema
Smoking cessation

Question 18

What is the appropriate management of acute COPD?

Answer 18

Controlled oxygen therapy (start at 24%)
- increase to 28% if ABG shows steady or decreased PaCO2 after 20 mins
- if PaCO2 increases give doxapram or assisted ventilation
Nebulisers
- 5mg salbutamol
- 0.5mg ipratropium bromide
7 days course of prednisolone 40mg
Treat the cause; usually a chest infection

Question 19

What are the most common causes of chest infection in COPD, and how is it treated?

Answer 19

Strep pneumoniae and haemophilus influenza
Clarithromycin 500mg
OR
Doxycycline 200mg - 100mg