Lecture 8.1: COPD

Question 1

What is the long form of COPD?

Answer 1

Chronic Obstructive Pulmonary Disease

Question 2

What is COPD?

Answer 2

• The name for a group of lung
  conditions that cause breathing
  difficulties
• It includes: emphysema (damage to
  the air sacs in the lungs), chronic
  bronchitis (long-term inflammation of
  the airways)

Question 3

What is COPD predominantly caused by?

Answer 3

Smoking

Question 4

What is COPD characterised by (NICE)?

Answer 4

• COPD is characterised by airflow
  obstruction
• The airflow obstruction is usually
  progressive
• Not fully reversible
• Does not change markedly over
  several months

Question 5

How many people in the UK are living with COPD?

Answer 5

1.2 million

Question 6

Risk Factors for COPD (7)

Answer 6

• Smoking
• Coal Mining/Mining of any kind really
• Asbestos Exposure
• People with Asthma
• Exposure to fumes from burning fuel
• Occupational exposure to dusts and
  chemicals
• Genetics

Question 7

Causes of COPD (4)

Answer 7

• Vast majority in HICs due to smoking
• Alpha-1 anti-trypsin deficiency
• Occupational exposure (e.g. coal dust)
• Pollution (including indoor smoke
  pollution)

Question 8

What percentage of Smokers get COPD?

Answer 8

15%

Question 9

What is Emphysema?

Answer 9

• A pathological process in which there is
  destruction of the terminal bronchioles
  and distal airspaces
• Leads to loss of alveolar surface area
• Spaces get bigger to form bullae

Question 10

Why do small airways collapse in Emphysema?

Answer 10

• Spaces get bigger to form bullae
• Destruction of tissues removes
  ‘scaffolding’ support of small airways,
  which tend to collapse
• Leads to airflow obstruction

Question 11

What is Pulmonary Compliance?

Answer 11

A measure of the lung expandability

Question 12

What is the Equation of Pulmonary Compliance?

Answer 12

Compliance = Δvolume/Δpleural pressure

Question 13

What is the effect of loss of tissue in Emphysema?

Answer 13

• Loss of tissue increases compliance
• Lung recoil reduced so lungs have
  higher resting expiratory level
• Hyperinflation

Question 14

Centrilobular/Centriacinar Emphysema

Answer 14

• Primarily the upper lobes
• Occurs with loss of the respiratory
  bronchioles in the proximal portion of
  the acinus
• With sparing of distal alveoli

Question 15

Panlobular/Panacinar Emphysema

Answer 15

• Involves all lung fields
• Particularly the bases

Question 16

What is Chronic Bronchitis?

Answer 16

A daily productive cough that lasts for 3 months of the year and for at least 2 years in a row

Question 17

Pathophysiology of Chronic Bronchitis

Answer 17

• Chronic mucus hypersecretion
• Mucus hyper secretion caused by
  inflammation in larger airways
• Leads to chronic productive cough and
  frequent infections
• Get re-modelling and narrowing of
  airways

Question 18

Symptoms of COPD (5)

Answer 18

• Cough
• Sputum Production
• Progressive Breathlessness
• Dyspnoea
• Increasingly frequent exacerbations

Question 19

MRC Dyspnoea Score (5 Grades)

Answer 19

• Grade 1: not troubled except in hard
  exercise
• Grade 2: short of breath when hurrying
  or walking up slight hill
• Grade 3: walks slower than
  contemporaries on level ground
  because of breathlessness
• Grade 4: stops for breath after walking
  100m or so
• Grade 5: too breathless to leave the
  house, or breathless on dressing and
  undressing

Question 20

Signs of COPD (10)

Answer 20

• ‘Purse Lip’ Breathing
• Increases pressure within airways to
  delay closure
• Tachypnoea
• Use of accessory muscles
• Hyperinflation (harder to breath)
• May have wheeze or quiet breath sounds
• Cyanosis
• Carbon dioxide retention
• Right heart failure (cor pulmonale)

Question 21

Investigations for COPD

Answer 21

• Spirometry
• Chest X-Ray
• High Resolution CT
• ABGs (to assess respiratory failure)
• Alpha-1 anti trypsin assay for younger patients

Question 22

How is Airflow Obstruction Staged?

Answer 22

• Mild airflow obstruction: FEV1.0 50-80%
  predicted
• Moderate airflow obstruction: FEV1.0 30-49%
  predicted
• Severe airflow obstruction: FEV1.0 <30%
  predicted

Question 23

Pathophysiology of Emyphsema

Answer 23

• Parenchymal destruction
• Matched V/Q defect
• Mild hypoxia
• Cachexia

Question 24

Pathophysiology of Chronic Bronchitis

Answer 24

• Airway inflammation
• V/Q mismatch
• Severe hypoxia and hypercapnia
• Pulmonary hypertension and cor pulmonale

Question 25

Cor Pulmonale

Answer 25

What is abnormal enlargement of the right side of the heart as a result of disease of the lungs or the pulmonary blood vessels

Question 26

2 Types of Management of COPD

Answer 26

* Stable disease management * Management of exacerbations

Question 27

Stable COPD Management (10)

Answer 27

* Smoking cessation support * Pulmonary rehabilitation * Bronchodilators * Anti-muscarinics * Steroids * Mucolytics * Diet * Influenza vaccination * Long term oxygen therapy in advanced disease * Lung volume reduction if appropriate

Question 28

Drug Therapy for COPD: Bronchodilators

Answer 28

* A type of medication that make breathing easier by relaxing the muscles in the lungs and widening the airways (bronchi) * Beta-2 agonists (eg salbutamol) * May help with emphysema even if there is no improvement in FEV1

Question 29

Adverse Effects of Beta-2 Agonists (5)

Answer 29

* Tachycardia * Tremor * Anxiety * Palpitations * Hypokalaemia

Question 30

Drug Therapy for COPD: Steroids

Answer 30

* Steroids help reduce inflammation

Question 31

Drug Therapy for COPD: Mucolytics

Answer 31

* Mucolytics help clear mucus * Carbocysteine

Question 32

Drug Therapy for COPD: Anti-Muscarinics

Answer 32

* Also known as anticholinergic agents * Are effective bronchodilators used in the treatment of chronic obstructive pulmonary disease (COPD) * Used to alleviate dyspnea and improve exercise tolerance

Question 33

Adverse Effects of Anti-Muscarinics

Answer 33

* Dry Mouth * Upper Respiratory Tract Infection * Nausea * Pharyngitis * Supraventricular Tachycardia * Atrial Fibrillation * Urinary Difficulty/Retetention * Constipation

Question 34

What is the Effect of Anti-Muscarinics on the Urinary System

Answer 34

* Decreasing the motility of smooth muscle cells in the urinary tract and increasing the tone of the sphincters controlling urination * They do this by inhibiting parasympathetic. stimulation of the myenteric and submucosal neural plexuses * Anticholinergic agent that blocks the activity of the muscarinic acetylcholine receptor

Question 35

Adverse Effects of Corticosteroids (10)

Answer 35

* Thin Skin * Bruising * Cataracts * Adrenal Insufficiency * Osteoporosis * Diabetes * Increased Weight * Mental Disturbance * GI Symptoms * Proximal Myopath

Question 36

Managing Acute Exacerbations (6)

Answer 36

* Aim for oxygen saturation 88-92% with. controlled oxygen therapy * Use nebulised bronchodilators * Oral/sometimes IV steroids * Antibiotics if suspect infection * Consider IV Aminophylline * If ABGs do not improve consider ventilator

Question 37

Long Term Oxygen Therapy

Answer 37

* Help to stop long term hypoxia leading to renal and cardiac damage * Continuous oxygen for at least 16 hours each day * Offered if arterial pO2 consistently below 7.3kPa * Patients must be non-smokers * Patients must not be retaining high levels of carbon dioxide * Balance with loss of independence

Question 38

Endobronchial Valves

Answer 38

* A small one-way valve, which may be implanted in an airway feeding the lung or part of lung * The valve allows air to be breathed out of the section of lung supplied * Prevents air from being breathed in * This leaves the rest of the lung to expand more normally and avoid air-trapping

Question 39

Pulmonary Rehabilitation Encourages...?

Answer 39

6-12 week supervised MDT programme of: * Exercise supervised and unsupervised at home * Diet * Disease education

Question 40

Why can't we give too much oxygen to COPD patients?

Answer 40

* Normal oxygen threshold is reduced in COPD patients * Giving them O2 increases saturation in lungs enough that their body breaths less * This means less CO2 is blown off * This could leads to hypercapnia which can be very dangerous