COPD

Question 1

What does COPD stand for?

Answer 1

Chronic Obstructive Pulmonary Disease.

Question 2

What is COPD?

Answer 2

This is a disease characterised by chronic bronchitis (inflammation of the lungs) and/or emphysema (constriction of the lungs) associated with airway obstruction and airway hyperreactiveiy. The disease cannot be cured, and is only partially reversible.

Question 3

How does the disease start and then develop?

Answer 3

The disease starts off as obstructive, then develops to restrictive, destroying alvaeoli and reducing lung capicity.

Question 4

What is the difference between Obstructive and Restricitve?

Answer 4

Obstructive: REduced airflow due to partial or complete obstruction. No change in total lung capacity.
Restrictive: Characterised by reduced lung expansion therefore leading to reduced total lung capcaity.

Question 5

The cause of almost all COPD:

Answer 5

Smoking

Question 6

What is the goal of management of COPD?

Answer 6

No cure, therefore goal is to reduce exacerbations and improve quality of life.
Stop Smoking is the best way to manage the progression of the disease.

Question 7

What is the first-presnetaton that we would supect COPD?

Answer 7

> 35, with a ‘smoker’s cough’. Unlikely to see COPD any sooner because it takes time to progress.

Question 8

What are the possible causes of COPD in the small % that are not smokers?

Answer 8

Passive smoking,
pollutants (where they used to work e.g. miners or cotton factory)
Rare genetic disease causing lung changes.

Question 9

What is the COPD pathology.

Answer 9

Partially-reversible airflow obstruction. Inflammation is mainly driven by Neutrophils and not eosinophils (in ashtma), and predominently invades in the peripheral lung (towards the edges of the lung).
There is epithelial shedding, damage to cilia, oedema, and irreversible loss of lung elasticity. There is Emphysema also. There is no thickening of the basement membrane, no hypertrophy or hyperplasia which is different to asthma. COPD patients also have a hyper-reactive airway.

Question 10

Is there mucous hypersecretion?

Answer 10

Yes but is less viscous than in asthma

Question 11

What is Emphysema:

Answer 11

This is lung damage by inflammation of the alveoli, enlargement of the air spaces distal to the terminal bronchioles, reduced surface area and elasticity, airway collapse and therefore increased effort to breathe and flushed cheeks.

Question 12

What Lymphocyte is involved in the COPD mechanism?

Answer 12

Type 1 T-helper lymphocyte (Th1)

Question 13

What is teh mechanism of the disease?

Answer 13

Smoking or other irritants will cause a cascade of immune response mainly through resident macrophages in the lung through Th1. The end result is thinning (fibrosis) of the airways, Emphysema (less surface area for gas exchange), Alveolar wall destruction and mucous hypersecretion.

Question 14

What are the Treatmetn options for managing the disease:

Answer 14

Main is remove irritant.
Corticosteroids
Beta agonists
Anticholinergics
Oxygen

Question 15

How do corticosteroids work in this disease?

Answer 15

Work against eosinophils, not neutrophils therefore these are not effective for COPD. They also increase the risk of pneumonia

Question 16

What is the first-line pharmacological treatment?

Answer 16

Sort acting bronchodilator inhaler:
1) SABA = short-acting Beta2 adrenoerceptor agonist.
e.g. Salbutamol or Terbutaline.
Immediate symptomatic relief by causing bronchodilation. They should be used before excericse to avoid an asthma attack.
or
2) Anticholinergics (Antimuscarinic inhalers) which block acetylcholine from causing bronchoconstriction e.g. Ipratropium
Both of these are used when required.

Question 17

What can be used if the 1st line treatment isn’t sufficient?

Answer 17

If more sever, regular inhaled treatment is required: A long-acting bronchodilator inhaler.
1) LABA = Long-acting Beta2adrenorecptor agonist e.g. Salmeterol with a onger duration of action of >12 hours. This drug must be given with a corticosteroid to avoid breakthrough attack e.g. Salmeterol + Fluticasone. Combination inhalers are available.
or
2) Long-acting antimuscarinic inhaler e.g. Tiotropium

Question 18

What if 2nd line therpay isn’t sufficient?

Answer 18

Triple therapy: Use a Combination inhaler of LABA and corticosteroid along with another inhaler of Long-acting antimuscarinic inhaler.

Question 19

If inhaled therapy isn’t sufficeint, what are the next steps?

Answer 19

Use oral Theophylline (xanthines) tablets which may prevent inflammatory cell activation and smooth muscle relaxation. They don’t give immediate relief of an attack, so still need SABA inhaler.

Question 20

What is the treatemtn in an emergancy episode of COPD exacerbation when B-agonists don’t work?

Answer 20

Aminophyline IV.

Question 21

What is the oxygen treatment?

Answer 21

RElieve symptoms, but patients have to carry it around in canisters which is bothersome.
Also danger of respiratory depression when too much oxygen is given.

Question 22

What is the efficacy of Corticosteroids in treating COPD?

Answer 22

Only reduce the exacerbations, they are not as effective as treating asthma because they targer eosinophils and not neutrophils.

Question 23

What are the investigations carried out to diagnose COPD?

Answer 23

1) spirometry - measure lung flow and capacity. Measure FEV1 and FVC. results are compared against predicted normal ranges and are base don sex, age, height, race. If the FEV <80%, and the FEV/FVC ratio is <0.7 then COPD possible
2) History and examination, smoking?
3) Chest x-ray
4) Full blood count
5) BMI