Chronic Obstructive Pulmonary Disease

Question 1

Define COPD?

Answer 1

COPD is characterised by chronic air flow obstruction which is not fully reversible.

It is a spectrum of disease ranging from chronic bronchitis to emphysema.

Airway obstruction: is defined as FEV1/FEV less than 0.7

Question 2

Define the typical history of a patient with COPD?

Answer 2

Breathless on exertion
Chronic cough
Regular sputum production
Frequent winter ‘bronchitis’ or wheeze

Patient aged >35 years
Significant smoking history +/- occupational history

Question 3

Describe the pathology of COPD and emphysema.

Answer 3

Chronic Inflammation causing peribronchial fibrosis and build up of scar tissue.

Mucocillary dysfunction:
Smoking and inflammation enlarge the mucous glands and cause goblet cell metaplasia and leading to healthy cells being replaced by more mucus-secreting cells. This leads to excess mucous blocking the airways and increasing the risk of infection.

Destruction of the structures supporting and feeding the alveoli causing the small airways to collapse during exhalation, which reduces the elastic recoil making exhalation more difficult.

Question 4

What are the risk factors of developing COPD?

Answer 4

Significant Smoking History
Inhalation of occupational dusts and fumes
Air pollution
Chronic bronchitis
Genetic (alpha 1 antitrypsin)

Question 5

What are the signs of COPD?

Answer 5

Respiratory Distress:
Exertional/Rest breathlesness
Tachypnoea
Increased use of accessory muscles (pec minor)

Respiratory:
Wheezing
Quiet breath sounds
Prolonged forced expiratory time 
Pursed lip breathing 
Abnormal posture patient may lean forward to aid breathing.
Cyanosis

Signs of CO2 retention:
CO2 flap
Drowsiness
Confusion

General signs:
Being underweight
Peripheral oedema
Hyperinflation of the chest
Downward displacement of the liver

Question 6

What investigations would you do for a patient with suspected COPD and what might you see?

Answer 6

FBC (anaemia of chronic disease or polycythaemia due to compensatory chronic hypoxia)

CXR-hyperinflation, flat diaphragm

Spirometry (will show an obstructive picture) needed for diagnosis. Including post bronchodilator therapy

ABG (may show CO2 retention with metabolic compensation)

Question 7

How is stable COPD managed?

Answer 7

Smoking cessation, annual flu and one off pneumoccal vaccine
Pulmonary rehab

Step 1:
-Salbutamol or Short acting anti muscarinic*

Step 2:

• If signs of steroid responsiveness e.g. raised eosinophils or hx of atopy then steroid and LABA
• if no signs of steroid responsiveness then add LAMA and LABA

Step 3:
-if on steroid then add LAMA in

Can give oral theophylline in severe cases
Mucolytics if productive cough

Question 8

What are the indications for long term oxygen therapy in COPD?

Answer 8

LTOT is indicated in patients with COPD who have:

• a PaO2 less than 7.3 kPa when stable on 2 ABG

OR

• aPaO2 7.3-8.0 when stable and one of the following:
• secondary polycythaemia
• peripheral oedema
• pulmonary hypertension.

Cannot be given to someone who is still smoking despite numerous resources being given to help stop

Question 9

What is long term oxygen therapy?

Answer 9

It is oxygen therapy at home which should be used for at least 15hours a day to receive benefit.

Greater benefit is seen in use of greater than 20hours a day.

It provides symptomatic relief as well as improving mortality. It is thought to improve mortality as it slows the progression into cor pulmonale and reduces the risk of secondary polycythaemia.

Question 10

What is important to bear in mind when using oxygen in a patient with COPD?

Answer 10

Aim for saturations between 88-92%

Due to chronically high levels of CO2 patients hypercapnic drive desentises so they rely on their hypoxic drive to breathe.

Question 11

When should non invasive ventilation be considered for use in patients with COPD?

Answer 11

If pt remains acidotic etc depsite maximal treatment for exacerbation

Question 12

What are the different methods of smoking cessation?

Answer 12

Nicotine replacement therapy

Varencline- partial nicotine agonist
-SE include nausea

Buporpion- norepinepherine and dopamine receptor uptake inhibitor and nicotine antagonist

• can increase risk of seizures
• contra indicated in epilepsy, pregnancy and breastfeeding

Question 13

Describe the management of an acute exacerbation of COPD?

Answer 13

Oxygen (aiming for 88-92%) consider NIV

Regular inh/neb salbutamol

Prednisolone po 30mg 5 days

If infection consider amoxicillin/clarithromycin/doxycycline
-if purulent sputum or signs of infection

If in hospital serial ABG monitoring if worried. CXR

Question 14

What is the most common cause of infective exacerbation?

Answer 14

H.influenzae

Question 15

What are the different stages of COPD?

Answer 15

All must have FEV1:FVC <0.7

1- FEV1 >80%
2- FEV1 50-79%
3- FEV1 30-49%
5- <30%

Question 16

When is prophylactic abx recommended in COPD?

Answer 16

Not smoke
Optimised standard treatments and continue to have exacerbations

Question 17

What is prophylactic abx of choice in COPD?

Answer 17

Azithromycin 250mg three times pr week.

Need LFTs and ECG to check QT interval (can cause prolongation)

Question 18

What spirometry results are consistent with COPD?

Answer 18

FEV1 reduced
FEV1:FVC reduced