COPD

Question 1

What is the definition of COPD?

Answer 1

A condition characterised by airflow obstruction that is progressive, not fully reversible, and associated with an abnormal inflammatory response of the lung to noxious particles or gases. It Includes chronic bronchitis and emphysema.

Question 2

How many diagnosed cases of COPD are there in the UK?

Answer 2

900,000

Question 3

What is the estimated prevalence?

Answer 3

3.7 million living with the disease

Question 4

What characterises COPD patients?

Answer 4

Age of onset (>35yrs), smoking, pollution, chronic dyspnoea, Sputum production, minimal diurnal or day to day FEV1 variation

Question 5

How is chronic bronchitis defined?

Answer 5

Usually defined clinically - Inflammation of the bronchi, cough, sputum production on most days for 3 months of 2 successive years. If patient is a smoker then symptoms improve with cessation.

Question 6

How is emphysema defined?

Answer 6

It is a destruction of the lung parenchyma. Histologically it is defined as an enlarged air spaces distal to the terminal bronchioles, with destruction of alveolar walls. Clinically it can be seen that the entrapment of air leads to high lung volumes but vital capacity, peak flow and FEV1 are all reduced.

Question 7

What are pink puffers and blue bloaters?

Answer 7

The ends of the spectrum for COPD.
Pink Puffers – high alveolar ventilation, near normal Pa02 and normal/low PaC02. Breathless but not cyanosed. They may progress to type 1 respiratory failure.
Blue Bloaters – low alveolar ventilation, low Pa02 and high PaC02. They are cyanosed but not breathless, may develop cor pulmonale(enlargement and failure of the right ventricle of the heart as a response to increased vascular resistance or high blood pressure in the lungs, pulmonary heart disease). Resp centres are insensitive to C02, so they rely on hypoxic drive to maintain resp effort NB. Careful with administering 02

Question 8

What is the aetiology of COPD?

Answer 8

Smoking (more than occasional), open fires, alpha 1 antitrypsin deficiency

Question 9

What are the symptoms of COPD?

Answer 9

Cough, sputum, dyspnoea, wheeze

Question 10

What are the signs of COPD?

Answer 10

Tachypnoea, use of accessory muscle to aid breathing, hyperinflation, reduced cricosternal distance (

Question 11

What are the complications of COPD?

Answer 11

Acute exacerbations +/- infection, polycythaemia (high red blood cell count), respiratory failure, cor pulmonale (oedema and raised JVP), pneumothorax from ruptured bullae, lung carcinoma

Question 12

What are the tests for COPD?

Answer 12

FBC: raised PCV (packed cell volume)
Chest X-Ray: Hyperinflation, meaning >6 anterior ribs seen above diaphragm in the mid-clavicular line), flat hemidiaphragms, large central pulmonary arteries, reduced peripheral vascular markings, bullae.
ECG: Right atrial and ventricular hypertrophy from cor pumonale.
ABG: Low Pa02 +/- hypercapnia
Lung function: FEV1

Question 13

What are the NICE COPD guideline severity stages?

Answer 13

Stage 1: Mild – FEV1 ≥80% of predicted
Stage 2: Moderate – FEV1 50-79% of predicted
Stage 3: Severe – FEV1 30-49% of predicted
Stage 4: V. severe – FEV1

Question 14

What are the NICE guidelines for treating COPD? General:

Answer 14

Stop smoking, encourage exercise, treat poor nutrition (diet advice + supplements) or obesity, administer mucolytics for productive cough, screen for depression, influenza and pneumococcal vaccination, pulmonary rehab/palliative care.
Administer PRN short active bronchodilators (Beta-2 agonists or anticholinergics)

Question 15

What are the NICE guidelines for treating COPD?

Mild/moderate:

Answer 15

Inhaled long-acting antimuscarinic or Beta-2 agonist (+/- short acting bronchodilators)

Question 16

What are the NICE guidelines for treating COPD?

Severe:

Answer 16

Long-acting beta-2 agonist and low-dose inhaled steroids OR long-acting anticholinergic

Question 17

What are the NICE guidelines for treating COPD?

If still symptomatic after severe:

Answer 17

Long-actin beta-2 agonist + regular low-dose inhaled steroids + regular long acting anticholinergic
Refer to specialist, consider steroid trial, home nebulizers, theophylline

Question 18

What are the NICE guidelines for treating COPD?

Pulmonary hypertension:

Answer 18

Asses the need for long-term 02 therapy (LOT), treat oedema with diuretics

Question 19

When should you consider LTOT?

Answer 19

1) Clinically stable non-smokers with Pa02

Question 20

Name 3 types of bronchodilator and give two examples of each.

Answer 20

Beta-2 agonists – Salbutamol (short-acting), Slameterol (long-acting)
Anticholinergics – Ipatropium (short-acting), Tiotropium (long-acting)
Methylxanthines – Aminophylline (short-acting), Theophyline (long-acting)

Question 21

Name the immunosuppressants used in COPD.

Answer 21

Inhaled steroids – Beclametasone

Oral steroids - Prednisolone

Question 22

How are the drugs ideally administered?

Answer 22

Topically, via inhalation. This allows a much smaller dose that would be needed systemically, and allows the short acting beta-2 agonists to be administered PRN, but can but can be administered more regularly in acute exacerbations.

Question 23

How do beta-2 agonists work?

Answer 23

Stimulate beta-2 adrenoreceptors (smooth muscle of bronchi, GI tract, uterus, blood vessels), increase C-AMP in smooth muscle which causes relaxation.

Question 24

What are the adverse effects of Beta-2 agonists?

Answer 24

Dose related, unlikely at inhaled doses, but when given IV/orally:

• tachycardia
• Arrythmias
• Tremor
• Anxiety
• Promote glycogenolysis
• Hypokalaemia (also stimulates Na+/K+ ATPase pumps)

Question 25

Are there any interactions?

Answer 25

Beta-blockers may reduce the effectiveness of beta-agonists

Concomitant use with theophylline and corticosteroids can lead to hypokalaemia

Question 26

What are the characteristics of anticholinergics?

Answer 26

Given by inhaler or nebuliser as there is no oral preparation. They are possibly more effective in elderly patients. They have few unwanted side-effects as the therapeutic dose is low.

Question 27

How do anticholinergics work?

Answer 27

Given by inhaler or nebuliser as there is no oral preparation. They are possibly more effective in elderly patients. They have few unwanted side-effects as the therapeutic dose is low.

Question 28

How is beclametasone administered?

Answer 28

Low dose usually give twice daily e.g. beclametasone (100-400mcg BD)

Question 29

Are there unwanted side effects?

Answer 29

Yes, oral candida, hoarse voice. This mainly due to poor inhalation technique, and systemic effects are rare.

Question 30

How do corticosteroids work?

Answer 30

They bind to the glucocorticoid response elements in the DNA, where they up-regulate anti-inflammatory genes and down-regulate pro-inflammatory genes which produce substances such as cytokines and TNF alpha. It also has a direct effect on cells such as eosinophils and neutrophils.

Question 31

Name 5 metabolic effects of corticosteroids?

Answer 31

•	Immunosuppression
•	Increased breakdown of muscle and fat
- Increased circulating fatty acids and amino acids
- Increased gluconeogenesis
- leads to muscle wasting and hyperglycaemia
•	Increased catabolism
- skin thinning, easy bruising, gastritis
- osteoporosis
•	Mineralocorticoid actions
- hypertension
- hypokalaemia
- oedema
•	Mood and sleep disturbance

Question 32

What happens to the normal hypothalamo-adrenal axis with long term steroid use?

Answer 32

• There is a suppression of ACTH secretion
• The normal stimulus for adrenal cortisol production is switched off
• This can lead to adrenal atrophy and loss of endogenous cortisol secretion
• Sudden withdrawl of steroids can lead to an Addisonian crisis (no cortisol)

Question 33

How do you manage an acute exacerbation of COPD?

Answer 33

1. Careful with O2 therapy….CO2 retainers need hypoxive drive
2. Administer regular bronchodilator therapy via nebuliser
3. Oral corticosteroid 7-14 days (40mg prednisolone)
4. Consider broad spectrum antibiotics to cover the usual pneumonia pathogens of Streptococcus pneumonia, H. influenza, and M catarrhalis
   - Amoxicilin, co-amoxiclav, doxycycline, clarithromycin