Lecture 8: COPD Flashcards

1
Q

What is the definition of COPD?

A

COPD is predominantly caused by smoking and is characterised by airflow obstruction that is not fully reversible

The airflow obstruction (AFO) does not change markedly over several months but is usually progressive in the long term

Exacerbations often occur, when there is a rapid and sustained worsening of the patient’s symptoms beyond normal day-to-day variations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In COPD, where are the sites of AFO?

A

Large Airway damage - bronchitis

Small airway damage - small airways disease obstruction ‘The silent zone’

Alveolar damage - emphysema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is chronic bronchitis?

A

Defined by symptoms

Epidemiological definition

  • Sputum production for 3 months per year
  • For at least two consecutive years

Histological correlate

  • Hyperplasia of mucus glands
  • Squamous metaplasia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is emphysema?

A

Defined by pathology

Destruction of alveoli distal to terminal bronchiole

Loss of elastic supporting tissue
Gas exchange affected as well as AFO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a bulla?

A

All sacs broken down – big airspace – would likely have this surgically removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the causes of COPD?

A

Smoking

Second Hand Smoke, especially in childhood

Globally: smoke inhalation from biomass fuels

Alpha-1 antitrypsin deficiency

Occupational: rail workers, coal miners, welders, painters, cleaners (but smoking is the main cause of COPD in all occupational groups)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a1-antitrypsin?

A

Alpha-1 antitrypsin (AAT) is aproteinthat is produced mostly in theliver

Its primary function is to protect thelungsfrom neutrophil elastase

Neutrophil elastase is an enzyme that normally serves a useful purpose in lung tissue - it digests damaged or aging cells and bacteria to promote healing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a1-antitrypsin deficiency?

A

Autosomal recessive inheritance

Homozygous PiZZ ~1 in 5,000

Not all develop emphysema

Smoking as co-factor, esp <40 years

~2% of all emphysema in UK

Minority also have liver disease

Heterozygotes not usually at risk if do not smoke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the typical symptoms of COPD?

A

Exertional breathlessness

Chronic cough

Regular sputum

Frequent winter bronchitis

Wheeze

Progressive SOB

Little/no reversibility

Constant symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the risk factors of COPD?

A

> 35 years

Significant smoking history

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What spirometry result would suggest COPD?

A

Post-bronchodilator FEV1/FVC < 70%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What FEV1 % of predicted suggests mild (stage1) COPD?

A

> 80%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What FEV1 % of predicted suggests moderate (stage2) COPD?

A

50-79%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What FEV1 % of predicted suggests severe (stage3) COPD?

A

30-49%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What FEV1 % of predicted suggests very severe (stage4) COPD?

A

<30

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the physiological effects of COPD?

A

Increased work of breathing

Reduced exercise tolerance

Impaired gas exchange

  • hypoxia
  • hypercapnia
  • raised pulmonary artery pressure
  • salt and water retention, RV dilatation
  • loss of Fat Free Mass
17
Q

What is first line pharmacological treatment for COPD?

A

SABA or SAMA

If symptoms persist use combinations

18
Q

What is the pulmonary rehabilitation scheme?

A
  • Supervised exercise training
  • Comprehensive educational programme
  • Psychosocial support

2 per week for 6 weeks

19
Q

What are the benefits to pulmonary rehabilitation?

A

Dyspnoea

Reduced SOB for a given amount or intensity of activity

Increased exercise capacity

Improved Health Related Quality of Life

20
Q

Why are ICSs only used for COPD as last choice?

A

ICS associated with increased incidence of CAP

21
Q

What are the benefits to inhaled therapy in COPD?

A

Reduce airflow obstruction

Reduce dynamic hyperinflation

Reduce symptoms

Reduce rate of exacerbations

22
Q

When is LTOT indicated for COPD?

A

LTOT is indicated in patients with COPD who have a pO2 < 7.3 kPa when stable

OR

pO2 7.3 – 8kPa and have one of:

  • secondary polycythaemia
  • nocturnal
  • hypoxaemia
  • peripheral oedema
  • pulmonary hypertension