103 - COPD

Question 1

What makes up COPD?

Answer 1

Chronic bronchitis
Emphysema
(assoc with small airways disease)

Question 2

What is bronchitis?

Answer 2

Cough, purulent sputum for 3+ months of the year for 2 years

Question 3

What changes occur in bronchitis?

Answer 3

Inflammation and narrowing - epithelium infiltrated by neutrophils - fibrosis
Increased mucous secretion
Squamous metaplasia - loss of cilia

Question 4

What is emphysema?

Answer 4

Destruction of lunch tissue distal to terminal bronchioles - loss off elasticity + radial traction

Question 5

What changes occur in emphysema?

Answer 5

Inflammation, proteases released, collagen and elastic breaks down - floppy airways, collapse on expiration
Hyperinflation

Question 6

What deficiency might cause an increased risk of emphysema?

Answer 6

Alpha-1 antitrypsin deficiency

Question 7

There are 2 types of respiratory failure in COPD, what are they?

Answer 7

Type 1 - pink puffers - emphysema - low PaO2, normal/low PaCo2, respiratory drive is maintained

Type 2 - Blue bloaters - Bronchitis - Low PaO2, High PaCo2 - Can’t keep high enough resp effort to keep PaCo2 down

Question 8

What types of bronchodilators are there?

Answer 8

B2 agonists - Salbutamol (SABA), Salmetrol (LABA)

Muscarinic antagonists - anticholinergics = Ipatropium, Tiotropium

Question 9

What is a side effect of an anticholingeric drug (eg. ipatropium)

Answer 9

Dry mouth

Question 10

What are the phyiological 4 aspects of respiration?

Answer 10

Ventilation
Diffusion
Perfusion
Ventilation-perfusion relationships

Question 11

How do you measure ventillation?

Answer 11

Spirometry

Total ventilation = tidal vol X resp frequency

Question 12

What drives air in and out of the lungs?

Answer 12

convection - pressure gradient

Question 13

What determines the functional residual capacity?

Answer 13

Balance of elastic recoil of lungs inwards, and the chest outwards

Question 14

What is fick’s law?

Answer 14

The rate of diffusion is proportional to the area of alveoli, inversly proportional to the thickeness

Question 15

What does tha Va/Q relationship determine?

Answer 15

Gas exchange

Question 16

What is the optimum Va/Q?

Answer 16

1

Normal lung is 0.84

Question 17

What is the Va/Q of the apex of the lung, why?

Answer 17

More than 1
Apex is poorly perfused
Both perfusion and ventilation is reduced due to gravity, bur gravity affects blood most

Question 18

What is the Va/Q of the base of the lungs? Why?

Answer 18

Less than 1
Base poorly ventilated
Both increased due to gravity, but affects blood most

Question 19

What condition do you get a lower than expected Va/Q?

Answer 19

Chronic bronchitis, asthma

Poor ventilation, impairs gas exchange, low PaO2 and impaired CO2 excretion

Question 20

What condition causes a higher than expected Va/Q?

Answer 20

Pul embolism
COPD

Poor perfusion means you get a high PaO2 but a low PaCO2, ventilation is wasted

Question 21

What does a Va/Q of 0 mean?

Answer 21

There is no ventilation - there must be a shunt

Question 22

What does a Va/Q of infinity mean?

Answer 22

There is no perfusion

occurs in dead space

Question 23

Which nerve supplies the respiratory muscles involved in control of ventilation?

Answer 23

Phrenic nerves

Question 24

What is the most important factor involved in controlling ventilation in normal people?

Answer 24

PaCO2

Question 25

Where is PaCO2 levels detected?

Answer 25

Central - medulla PaCO2 (80% of drive)
Peripheral - Carotid and aortic bodies PaCO2 and PaO2
Stretch receptors

Question 26

Where is lymph from the lungs drianed?

Answer 26

Bronchopulmonary nodes - tracheobronchial nodes - Bronchomediastinal nodes

Question 27

What level are the inferior boarders of the lung and plura?

Answer 27

Lung - 6, 8, 10th rib

Pleura - 8, 10, 12th rib