Chronic obstructive pulmonary disease (COPD)

Question 1

Define COPD

Answer 1

COPD is a chronic progressive obstructive disease of the airways with the two main components being chronic bronchitis and emphysema.
It is an umbrella term for the those two, and you can have one and not the other or have both.

Question 2

What are the two components of COPD?

Answer 2

Chronic bronchitis
Emphysema

Question 3

How does tobacco smoking lead to COPD - aetiology?

Answer 3

Tobacco smoke has many noxious chemicals and ROS. These cause tissue damage inducing an inflammatory response resulting in IL-8 and TNF-a release. These cause macrophage and neutrophil activation and trafficking = release proteases (trypsin, elastase, MMPs) which degrade the structural proteins so more damage and tf more inflammation.
The protease damage is even worse as the initial noxious chemicals and ROS cause antiprotease inactivation.
The tissue damage also causes impaired muco ciliary clearance so increased risk/more resp infections -> more inflammation.
Long term tissue damage -> tissue remodelling + thickening -> obstruction -> decreased respiratory function.

Question 4

What is chronic bronchitis and describe its pathophysiology

Answer 4

It is long-term inflammation of the bronchi and characterised by chronic and excessive sputum production, coughing and airway obstruction.

Cilia damage + mucus hypersecretion → Impaired mucocilliary clearance → Inc. risk of (Recurrent) Infection
Inflamed and swollen airway tissue/oedema → Irritation of sensory neurones → Cough (also caused by the excess mucus)
Loss of elastin -> weakened airway structure and loss of airway patency (Airway collapses)

Question 5

What is emphysema and its pathophysiology (how it develops)?

Answer 5

This is pathological enlargement of the distal airspaces in the alveoli due to alveolar wall degradation (so leading to merging). This can be detected on imaging e.g. CT

Patho = Inflammation in the lungs is usually countered by antiproteases (e.g. alpha-1 antitrypsin). Tobacco smoke’s noxious chemicals/ROS cause inactivation of these antiproteases.

Tf proteolytic enzymes (e.g. elastase) produced by macrophages/neutrophils break down the alveolar walls leading to enlargement of the terminal air spaces, reducing the SA available for gas exchange (particularly elastin). Loss of elastin in emphysema is what causes most of the air trapping.

Question 6

What are the main causes of COPD?

Answer 6

Tobacco smoking causes 90% of cases (incl passive, in utero). However, only 10% of smokers develop it which means there are other co factors involved (e.g. genetic pre dispositions)

Other causes include:
Alpha-1 Antitrypsin Deficiency (particularly emphysema)
Occupational exposure to dusts and fumes
Household air pollution from wood or coal burning

Question 7

What risk factors may make prognosis worse for COPD?

Answer 7

Age, ongoing smoking, reduced body weight, severe obstruction on spirometry (measured low FEV1), poor exercise tolerance, cor pulmonale

Question 8

What are the clinical symptoms of COPD?

Answer 8

Productive cough
Dyspnea (worse in exertion)
Wheeze
Recurrent lower respiratory tract infections
In more advanced cases, systemic symptoms such as weight loss and fatigue may be present

Question 9

What are the clinical signs of COPD?

Answer 9

Wheeze, coarse crackles, Hyperinflation of lungs (barrel chest), Pursed lip breathing, Accessory muscle usage, Cyanosis

Signs of cor pulmonale in severe COPD:
- Peripheral oedema
- Left parasternal heave
- Raised JVP
- Hepatomegaly

Question 10

What are the differentials of COPD?

Answer 10

Asthma
Bronchiectasis
Heart failure
Pulmonary fibrosis
Lung cancer
TB

Question 11

What are the investigations to diagnose COPD?

Answer 11

• Post-bronchodilator spirometry is the diagnostic test and is key to classifying severity. A post-bronchodilator FEV1/FVC ratio <0.7 confirms obstruction.
• CXR = may show symptoms of hyperinflation, bullae, flat hemidiaphragm. Also important to exclude lung cancer/bronchiectasis
• Bloods = FBC to see if secondary polycythaemia (copd can cause) or anaemic (exacer factor),
• Bloods = Alpha-1 antitrypsin levels in young pts/little smoking
• Body mass index (BMI) calculation

CT scan if suspecting alternative diagnoses (fibrosis, cancer or bronchiectasis)

Question 12

Who does NICE recommend investigating for COPD?

Answer 12

NICE recommend considering a COPD diagnosis in pts over 35 years who are smokers or ex-smokers and have symptoms such as exertional breathlessness, chronic cough or regular sputum production.

Question 13

What confirms diagnosis of COPD?

Answer 13

a post-bronchodilator FEV1/FVC ratio of <0.7

Question 14

What investigations may be done if cor pulmonale is suspected in COPD?

Answer 14

• BNP levels in blood
• Echo

Question 15

How is COPD severity classified?

Answer 15

The severity can be graded using the forced expiratory volume in 1 second (FEV1):

Stage 1 (mild): FEV1 more than 80% of predicted (these pts require symptoms in order to be diagnosed)
Stage 2 (moderate): FEV1 50-79% of predicted
Stage 3 (severe): FEV1 30-49% of predicted
Stage 4 (very severe): FEV1 less than 30% of predicted

Question 16

Brief outline of COPD management?

Answer 16

All patients with COPD should be offered education, smoking cessation, vaccinations, pulmonary rehabilitation (if indicated) and pharmacotherapy (e.g. inhalers).

Question 17

What is the non-medical management of copd?

Answer 17

• Patient education, ensure all patients have a personalised self-management plan
• Smoking cessation support
• Nutritional support
• Annual Flu and one off pneumococcal vaccinations
• Pulmonary rehabilitation if indicated

Question 18

Where is pulmonary rehabilitation indicated + contraindication in COPD?

Answer 18

Ind: offered to any patient with COPD who view themselves as functionally disabled by their condition (usually MRC grade 3 and above)

Contraind: patients unable to walk, unstable angina or have had recent MI

Question 19

What is pulmonary rehabilitation?

Answer 19

PR is an exercise and education program for people with chronic lung disease tf COPD. It involves:
- Exercise training
- Breathing techniques
- Education

Question 20

When is pharm management offered to COPD pts?

Answer 20

Inhaler therapies are offered if needed to relieve shortness of breath that limits their activities e.g. exercise limitation

Question 21

What is first line management of COPD and examples?

Answer 21

Offer a SABA (e.g. Salbutamol) or SAMA (e.g. Ipratropium) for patients to use on as needed basis

Question 22

What is the second step of management if symptoms still persist in COPD or have acute exacerbations? give one example of each med

Answer 22

Offer LABA+LAMA if no evidence of steroid responsiveness or asthmatic features)
OR
Offer LABA+ICS if evidence of steroid responsiveness or asthmatic features
LABA = Salmeterol, LAMA = tiotropium, ICS = beclomethasone

Question 23

What is the third step of management if symptoms still persist in COPD or have acute exacerbations? when is it specifically indicated

Answer 23

Offer escalation to triple therapy - (LABA + LAMA + ICS)

Indicated if:
Clin features affect QoL then offer 3 month trial. If no improvement, revert back to LABA + LAMA only
Or
1 severe or 2 moderate acute exacerbations within one year

Question 24

Give example of LABA and ICS combination inhaler

Answer 24

Seretide (salmeterol/fluticasone)

Question 25

Give example of LABA and LAMA combination inhaler

Answer 25

Ultibro (indacaterol/glycopyrronium)

Question 26

Give example of a triple therapy combination inhaler for COPD

Answer 26

Trimbow (formoterol/glycopyrronium/beclometasone)

Question 27

Give examples of LABAs

Answer 27

Salmeterol, formoterol and indacaterol

Question 28

Give examples of LAMAs

Answer 28

tiotropium, glycopyronium

Question 29

Give an example of an inhaled corticosteroid (ICS)

Answer 29

Beclomethasone

Question 30

How are COPD patients assessed for long term oxygen therapy?

Answer 30

• Must have stable COPD (not recovering from recent exacerb)

Patients then have two ABGs in air at least 3 weeks apart to see if they meet the criteria.

Question 31

When is there indication for long term oxygen therapy in COPD (criteria) and how long is it used?

Answer 31

LTOT is reserved for patients with stable COPD and meet this criteria:

Arterial Pa02 < 7.3 kPa
OR
Arterial Pa02 < 8 kPa with any of:
Pulmonary hypertension
Peripheral oedema
Secondary polycythaemia

Required for at least 15 hours a day to see benefit. No smoking while using it bc risk of fire/burn.

Question 32

When is there indication for surgery in COPD, give example of surgery

Answer 32

Rarely, surgical intervention may be offered to some patients. Recommended NICE one is lung volume reduction surgery (removing emphysema areas so that the healthy lung can expand)

E.g. pts with severe COPD who remain breathless despite maximal medical therapy

Question 33

What are complications of COPD?

Answer 33

• Acute exacerbation
• Cor pulmonale
• Recurrent pneumonia
• Pneumothorax
• Respiratory Failure (T2)
• Secondary polycythemia

Question 34

What is emergency presentation of COPD?

Answer 34

An acute exacerbation of COPD.

This is sudden worsening in airway function and respiratory symptoms in patients with COPD
Pts often require admission to hospital for treatment.

Worsening breathlessness
Worsening cough
Increased sputum production/Change in colour
Wheeze

Question 35

Common causes of COPD acute exacerbations?

Answer 35

Bacterial or viral resp infections (most common = rhinovirus)
Smoking
Env pollutants

Most exacerb are not bacterial.

Question 36

What is emergency management of COPD severe acute exacerbation?

Answer 36

Bronchodilators: usually given as nebulisers (SABA or SAMA e.g. Salbutamol or ipratropium)

Oxygen therapy using venturi mask if needed: Do not over oxygenate (keep 88-92%) bc COPD pts at risk of hypercapnia (too much O2 -> reduced hypoxic drive -> hypovent -> worse hypercapnia)

Corticosteroid = Prednisolone 30 mg once daily should be given for 5 days

Only give ABs if sputum is purulent or there are clinical signs of pneumonia (1st line are amoxicillin, Clarithromycin, Doxycycline