COPD

Question 1

What is the pathophysiology of COPD?

Answer 1

• Repeated injury to airways leads to structural and physiological changes and chronic inflammation
• These changes include narrowing and remodeling of airways, increased number of goblet cells, enlarged mucus glands, alveolar loss and changes to vascular bed leading to pulmonary hypertension.
• Elastin breakdown and loss of alveolar integrity leads to emphysema.
• Increased goblet cell size and number causes excessive mucus secretion.

Question 2

What is the physiological definition of COPD?

Answer 2

Increased airway resistance.
This is caused by reduced elastic recoil, fibrotic changes and luminal obstruction by secretions. The loss of elastic recoil leads to air trapping and therefore hyperinflation

Question 3

What are the causes of COPD?

Answer 3

• Smoking,
• Alpha-1 antitrypsin deficiency
• Others: Coal, cotton, cement, grain

Question 4

What is alpha-1 antitrypsin deficency?

Answer 4

Autosomal recessive condition which causes a lack of alpha-1 antitrypsin, a protease inhibitor normally produced by the liver.
It’s role is to protect cells from enzymes such as neutrophil elastase

Question 5

What are the features of alpha 1 antitrypsin deficiency?

Answer 5

Disease normally manifests in PiZZ genotype.
Lungs: Panacinar emphysema mostly in lower lobes.
Liver: Cirrhosis and hepatocellular carcinoma in adults, cholestasis in children.

Question 6

What are the investigations for alpha-1 antitrypsin deficiency?

Answer 6

A1AT concentrations
Spirometry - obstructive picture

Question 7

what are the symptoms and exam findings of COPD?

Answer 7

Symptoms - Productive cough, dyspnoea, wheeze, and in severe cases right sided heart failure which results in peripheral oedema.

Exam findings - Barrel chest, hyper-resonant percussion, wheezing, coarse crackles

Question 8

What is the definition of chronic bronchitis?

Answer 8

Production of sputum on most days for at least 3 months in at least 2 years.
Affects large airways greater than 4mm in diameter. Inflammation leads to scarring and thickening of airways.

Question 9

What is the definition of emphysema?

Answer 9

Abnormal, permanent enlargement of airspaces distal to the terminal bronchioles

Question 10

What are the features of ‘blue bloaters’

Answer 10

Type 2 respiratory failure (high CO2 and low O2) due to COPD which presents with following symptoms:
- Cyanosis,
- Warm peripheries,
- Bounding pulse,
- Flapping tremor,
- Confusion/drowsiness,
- Right heart failure,
- Oedema
- Raised JVP

Question 11

What are the features of ‘pink puffers’

Answer 11

Type 1 respiratory failure (low O2 and low CO2) due to COPD which presents with following:
- Desaturates on exercise,
- Pursed lip breathing,
- Use of accessory muscles,
- Wheeze,
- Indrawing of intercostals,
- Tachypnoea

Question 12

What are the different types of emphysema?

Answer 12

• Centri-acinar: damage occurs around bronchioles more in upper airways. Associated with smoking
• Pan-acinar: Uniformly enlarged from level of** terminal bronchiole distally**. Large bullae and associated with alpha 1 anti-trypsin deficiency.
• Paraseptal: Bullae are at risk of rupture and causing pneumothroax. Associated with fibrosis

Question 13

What are the investigations for COPD?

Answer 13

Post-bronchodilator spirometry - FEV1/FVC ratio less than 70%.
Chest X ray - Hyperinflattion (>6 anterior ribs), flat hemidiaphragm, bullae
FBC - exculse secondary polycythaemia
Sputum culture
BMI

Question 14

How do you classify severity of COPD

Answer 14

Based on % of predicted FEV1
Stage 1 = FEV1 >80%
Stage 2 = FEV1 of 50-79%
Stage 3 = FEV1 of 30-48
Stage 4 = FEV1 of < 30%

Question 15

What is the management of stable COPD?

Answer 15

Step 1 - SABA or SAMA
Step 2 with NO asthmatic features - Add LABA and LAMA. If already taking a SAMA then discontinue and switch to SABA
Step 2 with asthmatic features - Add ICS and LABA. If already taking a SAMA then discontinue and switch to SABA
Step 3 - Trial triple therapy with LABA, LAMA and ICS
Additions: Mucolytics if severe congestions

Smoking cessation

Question 16

When should oral theopylline be used in COPD?

Answer 16

People who cannot use inhaled therapy.
Dose should be reduced if macrolide or flouroquinolone is co-prescribed

Question 17

When are phosphodiesterase inhibitors recommended for COPD?

Answer 17

In severe asthma with FEV1 <50% predicted or 2+ exacerbations in last year despite triple therapy.

Question 18

What is the most common infective cause of COPD exacerbation?

Answer 18

Haemophilus influenza

Question 19

What are the features of an acute exacerbation of COPD?

Answer 19

Increase in dyspnoea, cough and wheeze.
Increase in sputum which may suggest infective cause
Hypoxia and confusion

Question 20

What is the primary care management of acute exacerbation of COPD

Answer 20

Increase frequency of bronchodialtor, consider nebs.
Give 30mg Prednisolone for 5 days
Antibiotics if sputum is purulent - Amoxicillin, doxycycline

Question 21

When should you admit a patient with IECOPD?

Answer 21

Severe breathlessness,
Acute confusion or low GCS,
Cyanosis,
O2 sats less than 90%
Social reasons
Significant comorbidity

Question 22

What is the management of IECOPD in secondary care?

Answer 22

Oxygen therapy - Aim sats 88-92%
Nebulised bronchodilator - Salbutamol or ipratropium
Steroids - Oral pred or IV hydrocortisone
IV theophylline if not responding to bronchodilators
If in type two resp failure with acidosis of <7.35 then use NIV.

Question 23

When should patient’s be offered long term oxygen therapy?

Answer 23

When pO2 < 7.3 kPa or pO2 of 7.8-8 kPa with one of following:
Secondary polycythaemia,
Peripheral oedema,
Pulmonary hypertension