General

Question 1

What is FEV1

Answer 1

Forced expiratory volume in 1 second

Person takes maximum inspiration and exhales maximally as fast as possible

Question 2

What % of vital capacity could a normal person expire in 1 second

Answer 2

80%

Question 3

See graph of Volume Time plot for forced expiratory volumes and make slides?

Answer 3

Plateaus

Rapid at start

Question 4

Draw Flow (L/s) against Volume (x axis) graph of forced expiratory volume

Answer 4

Flow is greatest at the start of expiration, it declines linearly with volume. FEF25 = flow at point when 25% of total volume to be exhaled has
been exhaled

Question 5

What is FVC

Answer 5

Forced vital capacity

The total amount of air forcibly expired

Question 6

How would you use FEV1 to assess lung health

Answer 6

Result is compared with the predicted values

If the FEV1 is 80% or greater than predicted value = NORMAL

Question 7

FEV1 below what % compared to predicted would be low

Answer 7

Less than 80% predicted would be abnormal

Question 8

How would you use FVC to assess lung health

Answer 8

The result is compared with the predicted values, if the FVC is 80% or greater than the predicted value = NORMAL
Thus is the FVC is less than 80% of the predicted value = LOW i.e abnormal

Question 9

What is healthy FEV1/FVC ratio

Answer 9

Greater than or equal to 0.7

Question 10

How would you diagnose an airway obstruction

Answer 10

FEV1/FVC ratio <0.7

Question 11

How would you diagnose an airway restriction

Answer 11

FVC < 80% predicted

Question 12

Patient has
FEV1 = 1.1
FVC = 1.2
(Predicted FEV1=3.6; FVC=4.55)

Answer 12

FEV1/FVC = 1.1/1.2 = 0.92
(normal)
FVC = 26% predicted
Therefore patient has airway restriction

Question 13

Patient has
FEV1 = 1.8
FVC = 3.3
(Predicted FEV1=2.94; FVC=3.70)

Answer 13

FVC = 89% predicted
(normal)
FEV1/FVC = 1.8/3.3 = 0.55
Therefore patient has airway obstruction

Question 14

Describe Type 1 respiratory failure

Answer 14

pO2 (partial O2 pressure) is low
pCO2 (partial CO2 pressure) is low or normal

(type 1 means 1 definite change = low pO2)

Question 15

Most common cause of Type 1 respiratory failure

Answer 15

Pulmonary embolism

form of ventilation-perfusion mismatch

Question 16

Describe Type 2 respiratory failure

Answer 16

pO2 is low
pCO2 is high

(2 definite changes in type 2)

Question 17

Example of cause of type 2 respiratory failure

Answer 17

Hypoventilation

Question 18

Causes of respiratory failure

Answer 18

Impaired ventilation
Impaired perfusion (extensive)
Impaired gas exchange defects (severe)

Question 19

Causes of impaired ventilation and thus respiratory failure

Answer 19

Neural problems e.g. narcotics, encephalitis, motor neurone disease (causing neuro-muscular weakness), cerebral space-occupying lesion etc

Mechanical problems e.g. airway obstruction (obstructive sleep apnoea), trauma, muscle disease and pleural effusion

Question 20

How does obstructive sleep apnoea cause airway obstruction and thus respiratory failure

Answer 20

Relaxation of pharynx during sleep results in occlusion causing stimulation and wakening

Question 21

Causes of impaired perfusion resulting in respiratory failure

Answer 21

Cardiac failure

Multiple pulmonary emboli

Question 22

Causes of impaired gas exchange defects resulting in respiratory failure

Answer 22

Emphysema

Diffuse pulmonary fibrosis

Question 23

What is hypercapnoea

Answer 23

High CO2 (see in type 2 resp failure if also has low O2)

Question 24

Signs of hypercapnoea

Answer 24

Bounding pulse
Flapping tremor
Confusion
Drowsiness
Reduced consciousness

Question 25

Examples of airways obstruction diseases

Answer 25

``` Asthma COPD (also airways restriction) Bronchiectasis Obstructive Sleep Apnoea Pneumonia ```

Question 26

Examples of diseases causing hypoventilation

Answer 26

``` COPD (emphysema) Neuromuscular weakness Obesity (OHS) Chest wall deformity Reduced drive (e.g. narcotics) ```

Question 27

Examples of diseases causing diffusion problems

Answer 27

Idiopathic Pulmonary Fibrosis Other Interstitial Lung Diseases Emphysema

Question 28

What type of airway issue is asthma

Answer 28

Reversible | Variable airflow obstruction

Question 29

What type of airway issue is COPD

Answer 29

Relatively fixed airflow obstruction | May be mixture of restrictive and obstructive disease

Question 30

Describe appearance restrictive lung disease

Answer 30

Lung volumes are small due to restriction Most breath is out in first second (low FEV1 and FVC)

Question 31

Example of restrictive lung disease

Answer 31

Interstitial lung disease e.g: | Fibrosing Alveolitis or Sarcoid

Question 32

What is transfer co-efficient

Answer 32

Measure of ability of oxygen to diffuse across the alveolar membrane

Question 33

How do you calculate transfer co-efficient

Answer 33

Can calculate by inspiring a small amount of carbon monoxide then hold breath for 10 seconds at total lung capacity (TLC) Then measure the gas transferred

Question 34

When would transfer co-efficient be low?

Answer 34

- Severe emphysema - Fibrosing alveolitis - Anaemia - Pulmonary hypertension - Idiopathic pulmonary fibrosis - COPD

Question 35

When would transfer co-efficient be high?

Answer 35

Pulmonary haemorrhage - can absorb O2 very efficiently due to bleeding resulting in more red blood cells being available

Question 36

Airways restriction is from scar tissue as restricted in how much can expand

Answer 36

True