Natalie - Lung Ventilatory Capacity and Disease

Question 1

Name two diseases that alter the volumes of the lung

Answer 1

Asthma

Cigarette-relating lung disease

Question 2

List the effects of lung diseases such as asthma on the lungs
(3)

Answer 2

Alter the volumes that can be contained within and expired from the lungs

Increase the resistance to gas flow

Cause breathing to become difficult and impair gas exchange

Question 3

What is vital capacity

Answer 3

The volume of air expelled from the lungs by the deepest possible expiration after they have been filled by the deepest possible inspiration

Question 4

What is forced vital capacity

Answer 4

When a vital capacity manoeuvre is carried out with maximal effort to expel all the vital capacity in the minimal possible time interval

FEV1 = forced vital capacity in 1 second

Question 5

What is the normal ratio of FEV1/FVC

Answer 5

FEV1 is normally 80%

Question 6

What may cause stroke volume to reduce?
(7)

Answer 6

Diseases of the thoracic cage

Acute injuries to thoracic cage

Diseases affecting nerve supply to respiratory muscles- muscular dystrophy

Abnormalities of the pleural cavity - pneumothorax

Pathology in the lung itself - fibrosis

Space-occupying lesions - cysts

Increased pulmonary blood volume - left heart failure

Question 7

What may cause a change in vital capacity
(2)

Answer 7

A change in stroke volume which is caused by a range of injuries and diseases

Diseases of the airways such as asthma and bronchitis

Question 8

What may affect Forced Expiratory Volume

Answer 8

Airway resistance affects this

Question 9

What will reduce airway resistance?
(5)

Answer 9

Bronchoconstriction - asthma

Inhalation of irritants - cigarette smoke

Structural changes in airways - chronic bronchitis

Obstruction in airways - inhaled foreign body or excess mucous

Destructive processes in lung parenchyma - emphysema

Question 10

List the obstructive disorders
(4)

Answer 10

Asthma

Chronic obstructive pulmonary disease = chronic bronchitis or emphysema or both together

Cystic fibrosis

Lung cancer/tumours

Question 11

What happens to air in terms of obstructive disorders?

Answer 11

Air inhaled normally but slow to come out

Question 12

What are the characteristic FVC results of an obstructive disorder?
(3)

Answer 12

Normal or slightly low FVC

Low FEV1

Low ratio e.g. 40-50%

Question 13

Write a note on chronic bronchitis
(6)

Answer 13

Blue bloaters

Daily productive cough for three months or more, in at least two consecutive years

Overweight

Peripheral oedema

Wheezing

Elevated hemoglobin

Question 14

Write a note on emphysema
(5)

Answer 14

Permanent enlargement and destruction of airspaces distal to the terminal bronchiole

Older and thin

Severe dyspnea

Quiet chest

X-Ray hyperinflation with flattened diaphragms

Question 15

List the restrictive disorders
(5)

Answer 15

Pulmonary fibrosis

Damage to rib cage

Skeletal disorder e.g. scoliosis

Muscular disorder e.g. Muscular dystrophy

Pulmonary oedema e.g. cor pulmonale

Question 16

List the test results of someone with restrictive disorder
(3)

Answer 16

Very low FVC

Low FEV1

High or normal ratio e.g. 90%

Question 17

Explain what happens to the air in a restrictive disorder

Answer 17

Air does not get in because of restriction

Question 18

Why are lung diseases a major problem in ireland

Answer 18

High incidence of smoking in young people

High incidence of cystic fibrosis

Question 19

Why are lung function tests so important
(2)

Answer 19

To diagnose patients early

Because once a patients develops COPD treatment is often disappointing

Question 20

What do you measure with a spirometer

Answer 20

Vital Capacity

Question 21

What information does a spirometer give us
(4)

Answer 21

Vital capacity

Tidal volume

Inspiratory capacity

Expiratory reserve volume

Question 22

What do we use to measure vital capacity

Answer 22

Spirometer

Question 23

What information does a spirometer not give us
(3)

Answer 23

residual volume

Functional residual capacity

Total lung capacity

Question 24

How are functional residual capacity and residual volume measured?

Answer 24

Using a body plethysmograph

Question 25

Write a note on the measurement of functional residual capacity

Answer 25

Measured using the body box

Body plethysmograph is used to measure this volume

Question 26

Why can’t we use a spirometer to measure FRC

Answer 26

FRC is the volume of air that cannot be moved out of the lung

Therefore we cant measure it using a spirometer

Question 27

What does FRC detect

Answer 27

Detects disease in the small airways which is caused by smoking

Question 28

What is residual volume

Answer 28

The volume of gas left in the lungs after maximal forced expiration

Question 29

What is the residual volume of a healthy person

Answer 29

About 2.5L

Question 30

Why would residual volume increase in emphysema?

Answer 30

Air cannot escape the lung

The inward alveolar elastic recoil is diminished -> airways collapse -> air gets trapped -> Barrel Chest syndrome

Question 31

Why is RV increased in obstructive diseases?

Answer 31

RV is raised because airway closure occurs too early and air becomes trapped in the lung

Question 32

When is reduced FRC and RV seen?

Answer 32

In patients with reduced lung compliance

Question 33

Explain in what conditions there is a reduced FRC and RV and why this is the case
(2)

Answer 33

Fibrosis -> lung is stiff and recoils to a smaller resting volume -> patient doesn’t get much air into the lung

Obesity -> can reduce compliance of chest wall also

Question 34

What happens to test results in an emphysema patient

Answer 34

Air in but slow to come out

Very high residual volume in emphysema

Question 35

What happens to test results in pulmonary fibrosis

Answer 35

Air does not get in - very low volumes

Low volume overall