Session 8: COPD

Question 2

What is COPD?

Answer 2

Airflow disease (obstructive) caused by two conditions. Usually progressive and associated with an abnormal inflammatory response to noxious particles and gases.

Question 3

COPD is an umbrella term for two conditions, which?

Answer 3

Chronic bronchitis Emphysema

Question 4

Aetiology of COPD

Answer 4

90% due to tobacco smoking. <10% due to alpha1-antitrypsin deficiency.

Question 5

When does COPD most commonly present?

Answer 5

In older patients which have smoked more or less their entire lives.

Question 6

Explain how alpha1-antitrypsin deficiency leads to COPD.

Answer 6

Alpha1-antitrypsin is an antiprotease. In this condition there is an imbalance between proteases and antiproteases in the lung. This leads to destruction of the alveolar walls and elastin leading to emphysema.

Question 7

When does alpha1-antitrypsin-associated COPD most commonly occur?

Answer 7

In young ages as it is inherited.

Question 8

Broad pathophysiology of COPD.

Answer 8

Exposure to tobacco smoking and other noxious particles leads to a chronic inflammatory response. This leads to oxidative injury which damages the parenchyma of the lungs, the peripheral airways, the vasculature as well as the alveoli.

Question 9

Two broad pathological changes occur in COPD, which?

Answer 9

Increased production of mucus and reduced clearance of mucus and associated pathogens. Respiratory defects + vasculature.

Question 10

Explain the cause of disrupted clearance of mucus and pathogens in COPD.

Answer 10

Enlargement of the mucus-secreting glands in the airways. Metaplasia of ciliated respiratory epithelium to normal columnar with increased expression of goblet cells. This also leads to ciliary destruction and dysfunction.

Question 11

Explain the respiratory defects and vasculature changes of COPD.

Answer 11

Breakdown of elastin leads to reduced elastic recoil. Also causes narrowing of bronchioles due to loss of radial traction. Also causes alveoli to collapse and form larger alveoli (formation of bullae). This leads to reduced surface area and reduced exchange. The vascular bed changes causes hypoxia, vasoconstriction and pulmonary hypertension.

Question 12

What is emphysema caused by?

Answer 12

Breakdown of elastin.

Question 13

Consequences of chronic bronchitis.

Answer 13

Increased mucus production and reduced clearance.

Question 14

Is COPD reversible?

Answer 14

No

Question 15

COPD leads to airway resistance. What causes it (think 3 changes)?

Answer 15

1 - Luminal obstruction because of increased mucus secretions and reduced clearance. 2 - narrowing of small bronchioles as radial traction is lost (outward pull) by elastin of surrounding alveoli. 3 - Elastin loss leads to reduced elastic recoil -> reduced expiratory force.

Question 16

What is the consequence of reduced expiratory force?

Answer 16

Hyperinflation

Question 17

State a cardiac consequence of COPD

Answer 17

Right heart failure (cor pulmonale)

Question 18

Explain how cor pulmonale can occur in COPD.

Answer 18

Hypoxia due to the obstructive nature of the disease. This leads to vasoconstriction of the pulmonary vessels. This vasoconstriction leads to pulmonary hypertension. This can lead to RV hypertrophy and subsequent R heart failure.

Question 19

What is the common history of a patient with COPD?

Answer 19

Older with a long history of smoking.

Question 20

What is the most common initial symptom of COPD?

Answer 20

Coughing

Question 21

Describe the initial cough associated with COPD.

Answer 21

Usually a morning cough that becomes more constant as the disease progresses. It is usually a productive cough meaning it produces sputum.

Question 22

The sputum of the cough in COPD may change. Due to what?

Answer 22

Exarcerbations or superimposed infections related to COPD.

Question 23

Give an example of another common initial symptoms of COPD.

Answer 23

Shortness of breath that may get worse upon exertion. This can progress to shortness of breath even on rest as the disease gets worse.

Question 24

Upon physical examination of a patient with COPD, what might you find? (Early to middle stages)

Answer 24

Tachypnoea Use of accessory muscles to aid the patients breathing Barrel chest Hyper-resonance upon percussion. Reduced intensity breath sounds Reduced air entry Wheezing (not as common)

Question 25

Cause of barrel chest.

Answer 25

Hyperinflation and air trapping secondary to incomplete expiration

Question 26

Cause of hyper-resonance upon percussion.

Answer 26

Hyper inflation and air trapping

Question 27

Late features upon physical examination in COPD.

Answer 27

Central cyanosis Flapping tremors Signs of right-sided heart failure.

Question 28

Cause of flapping tremors in late stage COPD.

Answer 28

Hypercapnia

Question 29

What are the signs of right-side heart failure in COPD?

Answer 29

Ankle oedema Distended neck veins (JVP) Hepatomegaly

Question 30

Investigations of COPD.

Answer 30

Spirometry DLCO (Decreased diffusing capacity of the lung for carbon monoxide) CXR Sputum sample

Question 31

In the case of acutely unwell COPD patients, what other investigation might you do?

Answer 31

Pulse oximetry and ABG levels

Question 32

In the case of a young person with COPD, what other investigation might you do?

Answer 32

Alpha-1 antitrypsin levels.

Question 33

How would spirometry show up on a patient with COPD?

Answer 33

FEV1/FEV ratio <70% Obstructive pattern with scooped curve Pattern doesn’t reverse upon use of bronchodilators.

Question 34

What might the CXR show on COPD?

Answer 34

Flattened diaphragm Hyperlucent lungs Increased diameter of the antero-postero chest.

Question 35

What else might the CXR show? (Not as common)

Answer 35

Complications of the COPD such as pneumonia or a pneumothorax

Question 36

Upon doing all the investigations for COPD. How will the results differ between COPD and asthma?

Answer 36

The spirometry patterns would reverse upon the use of bronchodilators. There would also be no decreased DLCO. Sputum sample in asthma might show eosinophils and can also be found in blood.

Question 37

Preventive and non-medical treatment of COPD.

Answer 37

Smoking cessation Patient education Pneumococcal vaccination to prevent pneumonia Pulmonary rehabilitation

Question 38

Medical treatment of COPD.

Answer 38

Bronchodilators (SABA, LABA, SAMA, LAMA) Inhaled corticosteroids Long term oxygen therapy Surgical intervention

Question 39

Explain why pulmonary rehabilitation is important.

Answer 39

As COPD gets worse the patient will get increased SOB upon exertion. This makes a lot of patients discouraged to exercise. This causes atrophy of respiratory muscles and leads to a vicious cycle of worsening symptoms. Can also lead to social isolation and depression.

Question 40

Why is long term oxygen therapy important?

Answer 40

Because extended periods of hypoxia causes pulmonary hypertension. This can lead to cor pulmonale.

Question 41

Explain how long term oxygen therapy is carried out.

Answer 41

Continuous low doses of oxygen at home or at least 16 hours in a day.

Question 42

Give examples of surgical interventions done in severe COPD.

Answer 42

Removal of large bull. Lung volume reduction. Lung transplant

Question 43

Definition of acute exacerbation of COPD.

Answer 43

Event characterised by change in the patient’s baseline (not general baseline) of dyspnoea, cough and sputum production and is acute onset.

Question 44

Give an example of why acute exacerbation of COPD might occur.

Answer 44

Infection

Question 45

What is the usual presentation of acute infectious exacerbation of COPD?

Answer 45

Severe SOB Fever Chest pain

Question 46

Management of acute exacerbation of COPD.

Answer 46

Pulse oximetry and ABG levels. Close monitoring of O2 sat Appropriate antibiotics Nebulised bronchodilators Oral steroids 24% or 28% O2 therapy with close monitoring of CO2 levels Non-invasive ventilation to not cause type 2 respiratory failure.

Question 47

Appropriate antibiotics are usually used to cover what pathogens?

Answer 47

Haemophilus influenzae Streptococcus pneumoniae

Question 48

What is the antibiotics usually used for these pathogens?

Answer 48

Amoxicillin

Question 49

Complications of COPD

Answer 49

Recurrent pneumonia Pneumothorax Respiratory failure Cor pulmonale