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 (chronic smoker changes)

Spirometry (will show an obstructive picture) needed for diagnosis.

ABG (may show CO2 retention with metabolic compensation)

Question 7

How is stable COPD managed?

Answer 7

Smoking cessation

Step 1:
-Salbutamol or Short acting anti muscarinic*

Step 2:

• If FEV1 is greater than 50%: Add in a LABA or a LAMA
• If FEV1 is less than 50%: Add in a LABA + inh corticosteroid OR a LAMA

Step 3:
-Add in the medication which is not being taken aka if on just a LABA add in inh corticosteroid. If on a combo add in LAMA.

If patients remain breathless on inhalers these medications can be given via a nebuliser

Oral theophylline can be used in advanced disease. A trial of oral corticosteroids may also be given.

Mucolytic medication can be used as an adjuvant therapy throughout. (Carbocisteine)

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.

OR

• aPaO2 greater than 7.3 and less than 8 kPa when stable and one of the following:
• secondary polycythaemia
• nocturnal hypoxaemia
• peripheral oedema
• pulmonary hypertension.

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

In an acute setting were a patient is decompensated despite O2 therapy.

In a non acute setting it should be considered in COPD patients with chronic hypercapnic respiratory failure who have previously needed NIV that are acidotic/hypercapnic despite LTOT.

Question 12

What are the different methods of smoking cessation?

Answer 12

Nicotine replacement therapy can be offered aka patches, e cigarettes, gum

Appointments with a HCA to monitor progress.

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 7-14days

+/- doxycycline 100mg od if infective (or local guidelines)

If in hospital serial ABG monitoring if worried. CXR