COPD

Question 0

What is COPD characterised by?

Answer 0

Airflow obstruction
Usually progressive
Not fully reversible
Does not change markedly over several months
Predominantly caused by smoking

Question 1

What is COPD?

Answer 1

An umbrella term encompassing emphysema and chronic bronchitis

Question 2

Causes of COPD?

Answer 2

Smoking
α-1 antitrypsin deficiency
Occupational eg coal dust
Pollution

Question 3

What does α-1 antitrypsin do?

Answer 3

Counteracts neutrophil elastase which breaks down alveoli

Question 4

What is seen in spirometry of emphysema?

Answer 4

Reduced FEV

Reduced FEV1/FVC ratio

Question 5

What is the pathological process of emphysema?

Answer 5

Destruction of the terminal bronchioles and distal airspaces
Leads to loss of alveolar surface area and therefore impairment of gas exchange
Progresses to bullae

Question 6

Why is emphysema an obstructive disease?

Answer 6

Get destruction of tissue supporting the small airways

They therefore tend to close during expiration when the pressure outside the airway rises

Question 7

Why in emphysema do you get hyperinflation of the lungs?

Answer 7

Loss of elastic tissue in the lung causes lungs to hyperinflate because lungs are unable to resist the natural tendancy of the ribcage to expand outwards

Question 8

What is chronic bronchitis?

Answer 8

Chronic mucus hypersecretion that frequently occurs in smokers

Question 9

What is the hypersecretion of mucus in chronic bronchitis caused by?

Answer 9

Inflammation in the large airways (normally due to cigarette smoke) leading to proliferation of mucus-producing cells in the respiratory epithelium.

Question 10

What does the hypersecretion of mucus lead to?

Answer 10

Productive cough

Frequent respiratory infections

Question 11

Why is chronic bronchitis an obstructive disease?

Answer 11

Get narrowing and remodelling of the airways

Question 12

Symptoms of COPD?

Answer 12

Cough and sputum production
Progressive breathlessness

Exacerbations associated with increased breathlessness and increased cough and sputum production, often infective

Question 13

Stages of the dyspnoea score?

Answer 13

1. Only breathless on strenuous exercise
2. Short of breath when walking uphill
3. Walk slower than contemporaries on level ground due to breathlessness, or have to stop for breath when walking at own pace
4. Stop for breath after walking 100m/few mins on level ground
5. Too breathless to leave the house, breathless when dressing/undressing

Question 14

Signs of COPD?

Answer 14

Purse-lip breathing
Tachypnoea
Prominent sternocleiodomastoid from accessory muscle use
Hyperinflation
Wheeze/quiet breath sounds on auscultation
Cyanosis and CO2 retention
Right heart failure with oedema in legs

Question 15

What investigations are done in diagnosing COPD and why?

Answer 15

Spirometry - FEV1, severity of airflow obstruction
CXR to exclude other diagnoses
HRCT scanning to assess degree of alveolar destruction in emphysema
ABG to assess resp failure
α-1 antitrypsin blood test for younger patients

Question 16

What drugs are used in treatment of COPD?

Answer 16

Bronchodilator - β2 agonists to cause relaxation of smooth muscle
Anticholinergics - synergistic with β2 agonists
Methylxanthines
Inhaled corticosteroids - reduce inflammation
Mucolytics - reduce thickness of sputum aiding airway clearance

Question 17

How do methylxanthines work?

Answer 17

Inhibit phosphodiesterases which normally break down cAMP
So get increased cAMP -> bronchodilation
Also increase respiratory drive and increase strength of respiratory muscles
Anti-inflammatory

Question 18

Side effects of β2 agonists?

Answer 18

Tachycardia
Tremor
Anxiety
Palpitations
Hypokalaemia

Question 19

Side effects of anticholinergics?

Answer 19

Dry mouth
Cough
Sore throat
Pharyngitis
Upper respiratory tract infection
Nausea
Supraventricular tachycardia
AF
Urinary difficulty and retention
Constipation

Question 20

Name some anticholinergics

Answer 20

Atropine
Ipatropium
Tiotropium

Question 21

Side effects of methylxanthines?

Answer 21

Tachycardia, SVT, nausea, seizures

Question 22

Why do COPD patients need pulmonary rehabilitation?

Answer 22

They try to avoid physical activity which leads to increased social isolation and inactivity
Makes symptoms worse - deconditioning

Question 23

What is pulmonary rehabilitation?

Answer 23

6-12 week programme of supervised exercise, unsupervised home exercise, nutritional advice and disease education

Question 24

Why do some COPD patients require long-term oxygen therapy?

Answer 24

Extended periods of hypoxia can lead to renal and cardiac damage

Question 25

How many hours a day is long term oxygen therapy (LTOT) required for?

Answer 25

16 hours to see a survival benefit

Question 26

At what point is LTOT offered?

Answer 26

If pO2 falls below 7.3kPa consistently
Or
Below 8kPa with cor pulmonale

Question 27

What requirements are there for patients before they can go on LTOT?

Answer 27

Non-smokers

Not retain high levels of carbon dioxide

Question 28

What are the problems with LTOT?

Answer 28

Loss of independence

Reduced activity

Question 29

Surgical options for COPD?

Answer 29

Lung volume reduction to reduce hyperinflation

Lung transplant in younger patients

Question 30

Management of acute exacerbations of COPD?

Answer 30

Oxygen therapy to increase SATS to 88-92%
Nebulisers - bronchodilators 
Oral/IV steroids
Antibiotics if infective 
IV aminophylline
Repeat ABG