Physiology

Question 1

What are the cut offs for the GOLD classification of airflow limitation severity in COPD (FEV1 percentage predicted of normal)?

Answer 1

Mild - 80% or more
Moderate - 50-79%
Severe - 30-49%
Very severe - <30%

Question 2

Is a lung with low compliance stiff or easily inflated?

Answer 2

It is stiff

Question 3

In emphysema, is compliance decreased or increased?

Answer 3

Increased (easier to inflate them due to loss of elastic tissue)

Question 4

Name a condition that would decrease pulmonary compliance

Answer 4

Pulmonary fibrosis

Question 5

Can the functional residual capacity (amount left in lung after a normal expiration) be measured by spirometry?

Answer 5

No as can’t measure residual volume.

Question 6

What is the approximate functional residual capacity in a young adult man?

Answer 6

2.2litres

Question 7

What condition is associated with a barrel chest?

Answer 7

Emphysema

Question 8

Will the TOTAL (not vital) lung capacity be increased or decreased with emphysema?

Answer 8

Increased as more air is trapped in the lungs

Question 9

What effect does emphysema have on the lung diffusion capacity and why?

Answer 9

Decreases lung diffusion capacity

Loss of alveoli leads to loss of surface area

Question 10

What do nitrates do to relieve shortness of breath in acute pulmonary oedema?

Answer 10

Dilates veins so reduces cardiac preload

Question 11

What oral medication can you give to treat dyspnoea in patients receiving palliative care?

Answer 11

Lorazepam

Midazolam if can’t tolerate oral