COPD

Question 1

What is COPD?

Answer 1

Chronic obstructive airway disease

- incompletely reversible poor airflow + inability to breathe OUT fully

Question 2

Give 2 examples of COPD. Why are they classified as COPD?

Answer 2

Emphysema
Chronic bronchitis
- poor airflow due to breakdown of lung tissue
- small airway disease
- results in poor absorption and release of respiratory gases

Question 3

When is there the greatest reduction of airflow in COPD and why?

Answer 3

Breathing out/exhalation

The pressure in the chest compresses the airways

Question 4

What are the risk factors for COPD?

Answer 4

1. Smoking (BIGGEST risk factor)
   - -> women more susceptible to harmful effects than men
2. Air pollution
3. Occupational exposure
4. Genetics (⍺-1-antitrypsin deficiency)

other risk factors may include:

• asthma + airway hyperactivity
• LBW
• HIV/AIDS and TB

Question 5

When should COPD be suspected?

Answer 5

In anyone over the age of 35-40 who has:

• SOB
• chronic cough
• sputum production
• frequent winter colds
• history of exposure to risk factors

Question 6

How is COPD diagnosed?

Answer 6

1. Spirometry:
   - FEV1:FVC is < normal range (~0.75-0.8)
2. Decrease in DLCO/TLCO (due to decreased surface area int he alveoli, as well as capillary bed)

*in the elderly spirometry would over-diagnose COPD
therefore, COPD symptoms, low FEV1:FVC and an FEV! < 80% of predicted is required for diagnosis

Question 7

Why can smoking lead to COPD?

Answer 7

• Smoking inactivates the elastase inhibitor ⍺-1-antitrypsin
• there is release of serine elastase
• elastic tissue of lung is destroyed

Question 8

Describe the different GOLD grades for severity of COPD.

Answer 8

1. Mild/GOLD1 = ≥ 80% of predicted FEV1
2. Moderate/GOLD2 = 50-79%
3. Severe/GOLD3 = 30-49%
4. Very severe/GOLD4 = <30%

Question 9

Describe the MRC shortness of breath scale in determining the severity of COPD.

Answer 9

1. grade 1 = only on strenuous activity
2. grade 2 = vigorous walking
3. grade 3 = with normal walking
4. grade 4 = after a few minutes of walking
5. grade 5 = with changing clothes

Question 10

What would a CXR of a COPD patient show?

Answer 10

• overexpanded lungs
• flattened diaphragm (most reliable sign)
• increased retrosternal airspace
• bullae

Question 11

What is the differential diagnoses for COPD?

Answer 11

1. congestive heart failure
2. pulmonary embolism
3. pneumonia
4. pneumothorax
5. bronchopulmonary dysplasia

Question 12

What are the goals of treatment for COPD?

Answer 12

1. reduce risk factors
2. manage stable COPD
3. prevent and treat acute exacerbations
4. manage associated illnesses

Question 13

Which vaccines must a person with COPD have and how often?

Answer 13

• influenza vaccine once a year

- pneumococcal vaccine every 5 years

Question 14

What are the treatment options for a COPD patient?

Answer 14

1. smoking cessation (reduce mortality)
2. O2 supplementation (reduce mortality)
3. exercise (pulmonary rehabilitation, ideal BMI)
4. bronchodilators
5. corticosteroids
6. long-term antibiotics (to reduce frequency of exacerbations)
7. surgery (transplant, or volume-reduction)

Question 15

When should O2 supplementation be given to a COPD patient?

Answer 15

When their ppO2 is <50-55mmHg or SaO2 <88%

**do not let SaO2 rise above 92%

Question 16

What kinds of bronchodilators are given? (give examples)

Answer 16

Major types are: 𝛃2 agonists and anticholinergics (long and short-term)

• reduce SOB, wheeze, exercise limitation, improve QOL
• long-acting partly work by reducing hyperinflation

Short-acting 𝛃2 agonists = salbutamol, terbutaline
Long-acting 𝛃2 agonists = formoterol, salmeterol, indacterol

*the anticholinergics used in COPD are antimuscarinics = ipratropium (short-acting) and tiotropium (long-acting)

Question 17

What is the MOA of antimuscarinics (anticholinergics)?

Answer 17

• blocks muscarinic receptors (some block M3 - tiotropium -, some are non-specific - ipratropium)
• this promoted the degradation of cyclic guanosine monophosphate (cGMP)
• decreased intracellular cGMP
• reduces intracellular cGMP
• reduces intracellular Ca2+
• prevents contraction if smooth muscle = bronchodilator etc

Question 18

What can trigger COPD exacerbations?

Answer 18

1. environmental pollutants (poor air quality)
2. infections
3. personal smoke and second-hand smoke
4. cold temperature

*bear in mind that pulmonary embolism can worsen the S+S of COPD

Question 19

How would a person with an acute exacerbation of COPD present?

Answer 19

• SOB
• increased sputum production
• change in colour of sputum (clear –> green/yellow)
• increase in cough
• tachypnoea
• tachycardia
• sweating
• active use of accessory muscles
• cyanosis
• confusion
• crackles on auscultation

Question 20

What happens/changes occur in a COPD patient when there is increased airway inflammation?

Answer 20

• increased hyperinflation
• reduced expiratory flow
• worsening of gas transfer
• can lead to insufficient ventilation = low SaO2
• result in narrowing of arteries of the lungs + breakdown of capillaries (emphysema)
• increased BP in pulmonary arteries

**can lead to cor pulmonale

Question 21

What is cor pulmonale?

Answer 21

abnormal enlargement of the right side of the heart

- can be caused by increased BP in pulmonary arteries as a result of COPD exacerbation

Question 22

How should a COPD exacerbation be treated/managed?

Answer 22

• usually by increasing the use of SABA
• can also combine with short-acting anticholinergics
• in this case you SHOULD give O2 as SaO2 is <88%
• continue to monitor pulse oximetry and ABGs
• corticosteroids could improve recovery and reduce duration of symptoms