COPD

Question 1

Describe COPD

Answer 1

Chronic obstructive pulmonary disease
Characterised by airflow obstruction
Obstruction is usually progressive, not fully reversible and does not change markedly over several months
Umbrella term for emphysema and chronic bronchitis

Question 2

Describe emphysema

Answer 2

Pathological destruction of terminal bronchioles and alveoli
Loss of alveolar SA, impairs gas exchange
Often progresses to development of large, redundant air spaces (bullae)
Destruction of supporting tissue (collapse during expiration)
Loss of elastic tissue (tend to hyperinflate - Barrel chest)

Question 3

Describe chronic bronchitis

Answer 3

Chronic mucus hypersecretion 
Frequently in smokers
Inflammation in the large airways 
Proliferation of mucus producing cells 
Chronic productive cough 
Frequent resp infections 
Air flow obstruction due to remodelling

Question 4

Name some causes of COPD

Answer 4

Smoking (commonest)
Alpha 1 antitrypsin deficiency
Occupational exposure (coal, dust)
Pollution

Question 5

Approximately what percentage of smokers develop COPD?

Answer 5

15%

Question 6

What are the symptoms of COPD?

Answer 6

Cough
Sputum production
Breathlessness

Question 7

What is the MRC dyspnoea score?

Answer 7

Grade of breathlessness

Question 8

Describe the stages of the MRC dyspnoea score

Answer 8

1. Not troubled except on strenuous exercise
2. Short of breath when hurrying or walking up a slight hill
3. Walks slower on level ground because of breathlessness or has to stop for breath when walking at own pace
4. Stops for breath after walking about 100m or after a few minutes on level ground
5. Too breathless to the leave the house or breathless when dressing/undressing

Question 9

What are the signs of COPD?

Answer 9

Purse lip breathing 
Tachypnoea 
Using accessory muscles
Hyperinflation 
Wheeze/reduced breath sounds
Advanced = cyanosis, CO2 retention, RH failure with oedema

Question 10

Why does a COPD patient purse their lips on breathing?

Answer 10

Protective manoeuvre that increases pressure within the airways
Reduction/delay in closure therefore easier to breathe out

Question 11

What is essential for diagnosing COPD?

Answer 11

A measurement of airflow obstruction

Spirometry

Question 12

How is spirometry performed and what does it measure?

Answer 12

Blow out as hard and as much as possible into a sealed tube

FEV1 and FVC measured

Question 13

Obstruction in COPD leads to a FEV1/FVC ratio of …

Answer 13

< 70%

Question 14

What ratio from spirometry would suggest mild obstruction?

Answer 14

50-80% predicted

Question 15

What ratio from spirometry would suggest moderate obstruction?

Answer 15

30-49% predicted

Question 16

What ratio from spirometry would suggest severe obstruction?

Answer 16

<30% predicted

Question 17

What features of a Hx are most suggestive of COPD?

Answer 17

Smoker/ex-smoker
Older patient (>40 years)
Chronic productive cough
Breathlessness that is persistent and progressive

Question 18

How is a COPD Hx different to asthma?

Answer 18

Likely to be smoker
Rare to get it <40 years 
Chronic productive cough 
Progressive and persistent breathlessness
Unlikely to wake you up at night 
No diurnal variation

Question 19

What investigations would we do for COPD?

Answer 19

CXR (mandatory to rule out other diagnoses)
CT - detailed assessment of degree of destruction
ABG - assess for resp failure
Alpha 1 antitrypsin blood test (younger people)

Question 20

Describe the COPD care bundle (Mx)

Answer 20

Smoking cessation 
Pulmonary rehab 
Bronchodilators 
Antimuscarinics 
Steroids 
Mucolytics 
Diet supplements 
Supportive things eg. Flu vaccine

Question 21

What do we consider as management for severe COPD patients?

Answer 21

Long term oxygen therapy

Lung volume reduction (surgery)

Question 22

Describe how beta 2 agonists work in obstructive diseases

Answer 22

Bind to beta 2 adrenoreceptors 
Activates adenyl cyclase 
Increased production of cAMP
Activates PKA
Phosphorylation of targets 
Inhibits SM contraction 
Relaxation of SM occurs

Question 23

What are some of the adverse side effects of beta 2 agonists?

Answer 23

Tachycardia/palpitations
Tremor
Anxiety
Hypokalaemia

Question 24

How do methylxanthines work?

Answer 24

Bronchodilation
Increased respiratory drive
Anti-inflammatory effects
Inhibition of phosphodiesterase to promote SM relaxation

Question 25

Give some side effects of long term steroid use

Answer 25

Thin skin/easy bruising
Cataracts 
Adrenal insufficiency 
GI symptoms 
Oestoporosis 
Diabetes 
Increased weight 
Mental disturbance

Question 26

What is pulmonary rehabilitation?

Answer 26

Exercise programme run at hospital 
6 weeks
All supervised
Be able to walk further and easier 
Give advice on disease 
Peer support

Question 27

Describe deconditioning

Answer 27

A viscous cycle of increasing social isolation and inactivity leading to worsening of symptoms

Question 28

When would we offer long term oxygen therapy for COPD?

Answer 28

If partial pressure oxygen consistently < 7.3 kPa
Non-smokers
Not retain high levels of carbon dioxide

Question 29

How long do you need to be on oxygen per day to confer a survival advantage?

Answer 29

At least 16 hours/day

Question 30

What is the management for acute exacerbation of COPD?

Answer 30

Bronchodilators via nebulisers
Steroids 
Abx if infective features 
Consider IV aminophylline 
Repeat ABG to check improvement

Question 31

When would we use non-invasive ventilation (BIPAP) in COPD?

Answer 31

Useful for acute exacerbation
With type 2 resp failure
And mild acidosis

Question 32

Why is the BIPAP machine not always a good option?

Answer 32

Patient must be conscious to use it

Need to breathe in sync with the machine

Question 33

Name some contraindications of non-invasive ventilation

Answer 33

Untreated pneumothorax (can make worse)
Impaired conscious level (GCS<8)
Upper airways secretions +++
Constant cough 
Facial injury 
Vomiting 
Agitated 
Life threatening hypoxia