COPD Flashcards Preview

Respiratory System > COPD > Flashcards

Flashcards in COPD Deck (33)
Loading flashcards...
1
Q

Describe COPD

A

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

2
Q

Describe emphysema

A

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)

3
Q

Describe chronic bronchitis

A
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
4
Q

Name some causes of COPD

A

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

5
Q

Approximately what percentage of smokers develop COPD?

A

15%

6
Q

What are the symptoms of COPD?

A

Cough
Sputum production
Breathlessness

7
Q

What is the MRC dyspnoea score?

A

Grade of breathlessness

8
Q

Describe the stages of the MRC dyspnoea score

A
  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
9
Q

What are the signs of COPD?

A
Purse lip breathing 
Tachypnoea 
Using accessory muscles
Hyperinflation 
Wheeze/reduced breath sounds
Advanced = cyanosis, CO2 retention, RH failure with oedema
10
Q

Why does a COPD patient purse their lips on breathing?

A

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

11
Q

What is essential for diagnosing COPD?

A

A measurement of airflow obstruction

Spirometry

12
Q

How is spirometry performed and what does it measure?

A

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

FEV1 and FVC measured

13
Q

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

A

< 70%

14
Q

What ratio from spirometry would suggest mild obstruction?

A

50-80% predicted

15
Q

What ratio from spirometry would suggest moderate obstruction?

A

30-49% predicted

16
Q

What ratio from spirometry would suggest severe obstruction?

A

<30% predicted

17
Q

What features of a Hx are most suggestive of COPD?

A

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

18
Q

How is a COPD Hx different to asthma?

A
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
19
Q

What investigations would we do for COPD?

A

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)

20
Q

Describe the COPD care bundle (Mx)

A
Smoking cessation 
Pulmonary rehab 
Bronchodilators 
Antimuscarinics 
Steroids 
Mucolytics 
Diet supplements 
Supportive things eg. Flu vaccine
21
Q

What do we consider as management for severe COPD patients?

A

Long term oxygen therapy

Lung volume reduction (surgery)

22
Q

Describe how beta 2 agonists work in obstructive diseases

A
Bind to beta 2 adrenoreceptors 
Activates adenyl cyclase 
Increased production of cAMP
Activates PKA
Phosphorylation of targets 
Inhibits SM contraction 
Relaxation of SM occurs
23
Q

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

A

Tachycardia/palpitations
Tremor
Anxiety
Hypokalaemia

24
Q

How do methylxanthines work?

A

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

25
Q

Give some side effects of long term steroid use

A
Thin skin/easy bruising
Cataracts 
Adrenal insufficiency 
GI symptoms 
Oestoporosis 
Diabetes 
Increased weight 
Mental disturbance
26
Q

What is pulmonary rehabilitation?

A
Exercise programme run at hospital 
6 weeks
All supervised
Be able to walk further and easier 
Give advice on disease 
Peer support
27
Q

Describe deconditioning

A

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

28
Q

When would we offer long term oxygen therapy for COPD?

A

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

29
Q

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

A

At least 16 hours/day

30
Q

What is the management for acute exacerbation of COPD?

A
Bronchodilators via nebulisers
Steroids 
Abx if infective features 
Consider IV aminophylline 
Repeat ABG to check improvement
31
Q

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

A

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

32
Q

Why is the BIPAP machine not always a good option?

A

Patient must be conscious to use it

Need to breathe in sync with the machine

33
Q

Name some contraindications of non-invasive ventilation

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