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Flashcards in COPD Deck (44)
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1
Q

Define COPD.

A

COPD is a progressive disorder characterized by airway obstruction with little or no reversibility. COPD is an umbrella term encompassing chronic bronchitis and emphysema.

2
Q

What is the obstructive picture seen with CODP patients who undergo lung function tests?

A

FEV1 of less than 80% predicted.
FEV1/FVC of less than 70% predicted.
FVC might be increased.

3
Q

Will the DLCO of a patient with COPD be changed?

A

Yes. Classically it will be decreased due to the large amount of residual air stuck in the lungs.

4
Q

What is the DLCO?

A

Diffusing Capacity of the Lung for Carbon Monoxide. It measures the extent to which oxygen gets from the air sacs into the blood.

5
Q

What does the DLCO assume about the patient?

A

That they have a normal levels of Hb.

6
Q

What might hide a low DLCO in a COPD patient?

A

Polycythaemia. Chronic hypoxia may lead to increased proportions of Hb in the blood.

7
Q

How many people die of COPD in the UK every year?

A

30,000.

8
Q

What are the main risk factors for COPD? (Name 3)

A

Smoking
Occupational exposure (such as mining)
Cooking on open fires
Alpha 1-antitrypsin deficiency

9
Q

What is used to define severity of COPD? What are the different levels of severity?

A

FEV1.
Mild - FEV1 greater than or equal to 80% predicted.
Moderate - FEV1 50-79% predicted.
Severe - FEV1 30-49% predicted.
Very Severe - FEV1 less than 30% predicted.

10
Q

What is step 1 in the approach to the treatment of COPD with regard to inhalers?

A

Short acting beta-2 agonist (salbutamol) or short acting anticholinergic (ipratropium) given PRN.

11
Q

What is step 2 in the approach to treatment of COPD with regard to inhalers (FEV1 >50%)?

A

Short acting bronchodilators PRN + regular long acting beta-2 agonist (salmeterol).

12
Q

What is step 3 in the approach to treatment of COPD with regard to inhalers (FEV1 <50%)?

A

Long acting beta-2 agonist + regular low dose inhaled steroids (beclomethasone).
OR
Regular long acting anticholinergic (tiatropium)

13
Q

What is step 4 (final step) in the approach to treatment of COPD with regard to inhalers?

A

Long acting beta-2 agonists + regular low dose inhaled steroids + regular long acting anticholinergic.

14
Q

What is the oral steroid used to treat an exacerbation of COPD and what is the standard dose?

A

Prednisolone, 30 mg

15
Q

What is a potential side effect of taking inhaled steroids? (Name at least 1)

A
Ora Candida infection
Other opportunistic infections
Hoarse voice
Cushing's syndrome
Addisonian crisis coming off the steroids
Steroid induced diabetes
Hypokalaemia
16
Q

What is the main treatment option for someone suffering from type II respiratory failure during an exacerbation of COPD who is not responding to medical therapy such as inhaled medication?

A

Non invasive ventilation.

17
Q

What should be done before someone is given non invasive ventilation (NIV)?

A

A clear plan is needed covering what to do in the event of deterioration. Ceilings of therapy should be agreed. This includes DNAR forms.

18
Q

What colour are DNAR forms?

A

Purple

19
Q

Name a short and a long beta agonist used in inhalers for COPD patients.

A

Short - salbutamol

Long - salmeterol

20
Q

Name a short and a long acting anticholinergic drug used in inhalers for COPD patients.

A

Short - Ipratropium

Long - tiotropium

21
Q

Name three combination inhalers and give the names of the individual drugs in the mixture.

A

Seretide - salmeterol and fluticasone
Fostair - formoterol and beclametasone
Symbicort - formoterol and budesonide

22
Q

What is the first step in an acute exacerbation of COPD?

A

2.5 mg of salbutamol through a nebuliser. Remember to record in drug chart whether this was driven by air or oxygen.

23
Q

Name at least 3 side effects of beta-2 agonists.

A
Tachycardia
Arrhythmia
Tremor
Anxiety
Promote glycogenolysis
Hypokalaemia
24
Q

In what type of patients might beta-2 agonists be less effective?

A

Cardiac patients on beta blockers.

25
Q

What is a standard dose of inhaled beclametasone?

A

100-400 micrograms BD

26
Q

What antibiotics would be used to treat someone with an infective exacerbation of COPD? What are the most common bacteria you are worried about?

A

Broad spectrum to cover S. pneumoniae, H. influenzae and M. catarrhalis. This could be amoxillin, co-amoxiclav, doxycycline or clarithromycin.

27
Q

Would a chest x-ray of someone with an infective exacerbation of COPD show any consolidation?

A

Not likely. This would be seen with a pneumonia.

28
Q

Which key test would we want to do on a patient who was having a severe exacerbation of COPD?

A

ABG

29
Q

What is the underlying cause of death in patients who die during a severe exacerbation of COPD?

A

Respiratory acidosis

30
Q

What is the normal DLCO range at rest?

A

24-36 ml/min/mmHg

31
Q

How is the DLCO measured?

A

Air with a known concentration of CO is inhaled, held for ten seconds and exhaled back into a bag. The difference is used to measure the flow rate into the blood.

32
Q

What is the KCO?

A

The transfer coefficient. It is an expression of gas transfer ability per unit volume of lung. It is the DLCO divided by the alveolar volume.

33
Q

What factors are the normal values of KCO dependent on?

A

Age and sex.

34
Q

What is the KCO used for?

A

It is used to interpret a reduced DLCO. If the patient has a reduced DLCO but normal KCO, then the likely cause is a reduction in lung volume. However, if both the DLCO and KCO are reduced then the underlying cause is damage to lung parenchyma, e.g. emphysema.

35
Q

Will the DLCO and KCO both be reduced in pulmonary fibrosis? Explain why.

A

Yes. The DLCO will be reduced because there is a reduced lung volume due to the scarred tissue. KCO is also reduced, despite the fact that the lung volume is decreased because the lung parenchyma itself is damaged and this means that it is not efficient at transferring oxygen from alveoli.

36
Q

Will the DLCO and KCO both be reduced in a patient with COPD who suffers more from chronic bronchitis than emphysema? Explain why.

A

The likelihood is that both will be reduced but not as much as in a patient who suffers from emphysema. This is because neither the lung volume nor the lung parenchyma are affected in chronic bronchitis, therefore diffusion capacity in the lung actually stays normal and the concentration of CO in the exhaled sample will be reduced by a normal amount. The only reason that the likelihood is that both will be slightly reduced is that most COPD patients will always have an element of emphysema.

37
Q

What are the possible complications of COPD?

A

Respiratory failure
Polycythaemia
Cor pulmonale
Pneumothorax - ruptured bullae

38
Q

What is the most likely underlying mechanism of emphysema? Describe it.

A

The protease anti-protease mechanism.

The walls of acinus are destroyed when there is an imbalance between proteases and anti-proteases in the lung. Protease is an enzyme like elastase, which can digest connective tissue elements. Proteases are found throughout the body, especially in neutrophils and macrophages. To counterbalance the destructive effects of proteases, nature provides inhibitors such as alpha-antitrypsin. Smoking increases the level of lung proteases while impairing the action of anti-proteases. Patients with panacinar emphysema may lack alpha-antitrypsin.

39
Q

What is chronic bronchitis?

A

A chronic inflammation of the trachea, bronchi and bronchioles, which is characterized by hypersecretion of mucous and thickening of the walls of respiratory tree.

40
Q

What parts of the respiratory system are affected by centriacinar emphysema?

A

The respiratory bronchiole (proximal and central part of the acinus) is expanded. The distal acinus or alveoli are unchanged. Occurs more commonly in the upper lobes.

41
Q

What parts of the respiratory system are affected by panacinar emphysema?

A

The entire respiratory acinus, from respiratory bronchiole to alveoli, is expanded. Occurs more commonly in the lower lobes, especially basal segments, and anterior margins of the lungs.

42
Q

What parts of the respiratory system are affected by distal acinar (paraseptal) emphysema?

A

The distal respiratory acinus, including alveolar duct and alveoli, is expanded. Occurs primarily adjacent to the pleura and connective tissue septa, especially in the upper lobes.

43
Q

Emphysema can be divided into four subgroups. Can you name them?

A

Centriacinar
Panacinar
Distal acinar (paraseptal)
Irregular (Paracicatritial)

44
Q

What causes the narrowing of the airways in chronic bronchitis?

A

Smoking causes increased secretion of mucus into the lumen of the respiratory tree. There is a marked increase in the size of the mucus secreting glands of the submucosa in the trachea and large bronchi. There is also a marked increase in goblet cells in the small bronchi and bronchioles. There will also be squamous metaplasia and dysplasia of bronchial epithelium.