COPD

Question 1

Give a general description of COPD

Answer 1

“COPD is characterised by airflow obstruction… usually progressive, not fully reversible and does not change markedly over several months. The disease is predominantly caused by smoking”

Question 2

What are the two main types of COPD?

Answer 2

Emphysema

Chronic bronchitis

Question 3

What is the aetiology of COPD?

Answer 3

SMOKING
Exposure to pollutants at work
Alpha 1 antitrypsin deficiency causes early onset.

Question 4

How does smoking cause COPD

Answer 4

Cigarette smoke causes mucous gland hypertrophy in the larger airways and leads to an increase in neutrophils, macrophages and lymphocytes in the airway walls.
These cells release inflammatory mediators which amplify the process. (elastases, proteases, Interleukins and TNF)
This produces a protease anti-protease imbalance—> breaks down lung parenchyma (emphysema)
alpha 1 antitrypsin is a major protease inhibitor which is inactivated by cigarette smoke.

Question 5

In chronic bronchitis airway narrowing causes airways obstruction. What causes airway narrowing?

Answer 5

Airway inflammation

Airway fibrosis, luminal plugs

Question 6

Emphysema is associated with decreased expiratory airflow and air trapping, what causes this?

Answer 6

Parenchymal Destruction
Loss of alveolar attachments
Decrease of elastic recoil

Question 7

What people most commonly get COPD?

Answer 7

elderly smokers with a male predominance

Without alpha 1 antitrypsin deficiency patients are usually symptomless until middle age

Question 8

What are clinical signs of COPD?

Answer 8

Shortage of breath
Cough, phlegm
Wheeze
Hyper-expansion/ barrel shaped chest
Cyanosis
Weight loss
‘cor pulmonale’ = ‘heart failure’ raised JVP, Swelling of ankles but CO maintained

Question 9

What is pink puffer associated with clinically?

Answer 9

mostly emphysema. Breathlessness is the main problem they are not cyanosed

Question 10

What is blue bloater associated with clinically?

Answer 10

Blue bloater- mostly chronic bronchitis. Cyanosed and may be oedematous, have features of CO2 retention.

Question 11

What is airway obstruction indicated by?

Answer 11

FEV1 <80% of predicted

FEV1 <70% of FVC

Question 12

What would reversibility testing show in a patient with COPD?

Answer 12

Less than 15% reversible

Question 13

What would Tco show?

Answer 13

Low due to fibrosis and emphysematous loss

Question 14

What would an ABG show>

Answer 14

Hypoxia

hypercapnia if severe

Question 15

What emphysematous changes may be seen on an Xray?

Answer 15

Emphysematous bullae

Question 16

Diagnosis made upon confirmation of airflow limitation and a history of breathlessness and sputum production in a smoker.
What is the differential diagnosis for SOB?

Answer 16

Heart failure, Pulmonary embolus, Pneumonia, Lung cancer, Asthma*, Bronchiectasis

Question 17

What lifestyle advice is recommended for patients?

Answer 17

SMOKING CESSATION

Question 18

What should COPD be treated with?

Answer 18

O2 to improve hypoxemia to target sats of 88- 92%

SABA for exacerbations

Systemic corticosteroids (prednisone) improve recovery time and lung function.

Antibiotics to patients with:
Increased dyspnoea, increased sputum volume and purulence or who require mechanical ventilation

Noninvasive ventilation (NIV)

Question 19

What are normal ranges for PaO2

SO2 and PaCO2

Answer 19

Normal PO2= 12-13 KPa or 90-100mmHg 
Normal SO2 (saturation) = 95-100% 
Normal PCO2= 4.6-6 KPa

Question 20

What prophylaxis should be offered to patients with COPD

Answer 20

Influenza and pneumococcal vaccination