Respiratory - COPD

Question 1

What is COPD?

Answer 1

A non-reversible deterioration in air flow through the lungs caused by the damage to lung tissue

Lung obstruction isn’t significantly reversible with bronchodilators like salbutamol

Question 2

Differentials of COPD

Answer 2

Lung cancer
Fibrosis
Heart failure

Question 3

Presentation of COPD

Answer 3

Chronic SOB
Chronic cough often with sputum production
Wheeze
Recurrent respiratory infections

Unusual for it to cause haemoptysis or chest pain - these symptoms should be investigated for a different cause

Question 4

Diagnosis and investigations

Answer 4

Based on clinical presentation and spirometry

Also:

• CXR - to exclude other pathology e.g. cancer
• FBC - polycythaemia or anaemia. Polycythaemia (raised haemoglobin) is a response to chronic hypoxia.
• Sputum culture - to assess for infections in exacerbation
• ECG and echo - heart function
• CT thorax - for alternative diagnoses e.g. fibrosis, cancer, bronchiectasis
• Serum alpha-1 antitrypsin to look for alpha-1 antitrypsin deficiency. Deficiency leads to early onset and more severe disease.
• Transfer factor for carbon monoxide (TLCO) is decreased in COPD.

Question 5

What will spirometry show in COPD?

Answer 5

An obstructive picture
(FEV1/FVC ratio <0.7)

Does not show dramatic response to reversibility testing with beta-2 agonists e.g. salbutamol (as would be seen in asthma)

Question 6

What are FVC and FEV1?

Answer 6

FVC - forced vital capacity (a measure of overall lung capacity)

FEV1 - ability to quickly blow out air
- Is lower in COPD - ability to blow air out is limited by the damage to their airways causing airway obstruction

Question 7

Conservative management of COPD

Answer 7

Stop smoking

Yearly pneumococcal and flu vaccine

Question 8

Medical management stepwise approach for COPD

Answer 8

1. SABA or SAMA - first line
2. Depends on patient:
   - If no asthma or features of steroid responsiveness - add LABA + LAMA
   - If they have asthma, features of steroid responsiveness - add LABA + ICS
3. Triple therapy - if patients are continuing to have exacerbation —LABA+LAMA+ICS

Long term oxygen therapy can also be used
- Used for some COPD patients - criteria

Question 9

Criteria for LTOT consideration in COPD patients

Answer 9

PaO2 <7.3

or PaO2 <8.0 with one of:

• Secondary polycythaemia
• Peripheral oedema
• Pulmonary hypertension
• Shown on 2 ABGs on separate occasions

Question 10

Investigations in exacerbation of COPD

Answer 10

ABG

CXR

ECG

FBC, U&Es

Sputum cultures

Blood cultures (if septic)

Question 11

Oxygen therapy in COPD - target saturations

Answer 11

If retaining CO2 - aim for saturations of 88-92% with venturi mask (24% or 28% ones usually)

If not retaining CO2 then can aim for saturations of >94% with NRB mask

Question 12

Management of COPD exacerbations

Answer 12

Well enough to remain at home:

• 30mg oral prednisolone for 5 days
• Regular inhalers or home nebulisers
• Antibiotics if signs of infection

Hospital:

• Nebulised bronchodilators e.g. salbutamol and ipratropium
• 30mg prednisolone PO for 5 days (or hydrocortisone 200mg IV)
• Antibiotics if signs of infection
• Physiotherapy can help clear sputum

If not responding to first line treatment:

• IV aminophylline
• Non-invasive ventilation
• Intubation and ventilation with admission to ITU