Pulmonary Function Tests

Question 1

What 3 things cause a variation in ventilatory performance?

Answer 1

Height
Age
Sex

Question 2

What is the standard deviation for vital capacity (VC)?

Answer 2

500ml

Question 3

What is ventilation?

Answer 3

The process of moving air in and out of the lungs

Question 4

What is the tidal volume?

Answer 4

The volume of air that enters and leaves the lungs during normal breathing

Question 5

What is the functional residual capacity?

Answer 5

The volume of gas within the lungs at the end of a normal expiration

Question 6

What is the total lung capacity?

Answer 6

The volume of gas in the lungs after a full inspiration

Question 7

What is the residual volume

Answer 7

The volume of gas remaining in the lungs after a full expiration

Question 8

What is the Vital Capacity

Answer 8

The volume of air expelled by a full expiration from a position of full inspiration

Question 9

How can we measure VC

Answer 9

Spirometry

Question 10

How are residual volume and total lung capacity measured?

Answer 10

Using gas dilution or plethysmography mehtods

Question 11

What is the most commonly used lung function test

Answer 11

Spirometry

Question 12

What does spirometry measure

Answer 12

The amount and the speed of airflow that can be exhaled

Question 13

What might reduce the FVC

Answer 13

Any condition that limits the lungs ability to achieve a full inspiration 
Lung fibrosis
Loss of lung volume 
Kyphoscoliosis
Ankylosing spondylitis
Muscle weakness (myopathy 
Myasthenia gravis
COPD

Question 14

What is FEV1

Answer 14

The volume of air expelled in the first second of a maximal forced expiration from a position of full inspiration

Question 15

What reduces the FEV1

Answer 15

Any condition that reduces VC

Question 16

How is an obstructive defect detected

Answer 16

When the ratio of FEV1/FVC is less than 0.7

Question 17

How is a restrictive defect detected

Answer 17

When the ratio is normal but there is a reduced FEV1 and FVC

Question 18

What is the Peak expiratory flow

Answer 18

The maximum rate of airflow that can be achieved during a sudden forced expiration from a position of full inspiration

Question 19

How many times is the PEF completed

Answer 19

3 times and and the best score is taken

Question 20

What causes a reduced TLC

Answer 20

Restrictive lung disease

Question 21

What causes an increased TLC?

Answer 21

Manifestation of hyperinflation

Question 22

Changes in PCO2 are termed as what

Answer 22

Respiratory

Question 23

Changes in HCO3 are termed as what

Answer 23

Metabolic

Question 24

What does a disturbance in one system tend to promt

Answer 24

A compensatory response in the other

Question 25

What is a general principle of compensation

Answer 25

Physiological copensatory mechanisms do not overcompensate. They often stop just short of total correction

Question 26

What is the most likely abnormality with an increased pH

Answer 26

Alkalosis

Question 27

What is the most likely abnormality with a decreased pH

Answer 27

Acidosis

Question 28

Describe the changes found in acute respiratory acidosis

Answer 28

Reduced pH Increase PCO2 Normal bicarbonate level

Question 29

Describe the changes found in chronic respiratory acidosis

Answer 29

pH normal Increased PCO2 High Bicarbonate level

Question 30

What can cause acute respiratory acidosis

Answer 30

Obstruction of the airway Overdose of sedative drugs Acute neurological damage

Question 31

What can cause chronic respiratory acidosis

Answer 31

Any process that results in sustained hypoventilation | COPD

Question 32

Describe the changes in respiratory alkalosis

Answer 32

pH raised PCO2 reduced Normal bicarbonate level

Question 33

Describe the changes in metabolic acidosis

Answer 33

pH reduced PCO2 reduced Bicarbonate reduced

Question 34

What can cause respiratory alkalosis

Answer 34

``` Hyperventilation Pulmonary ebp;os, Acute severe asthma Anxiety related hyperventilation Salicylate poisoning ```

Question 35

What can cause metabolic acidosis

Answer 35

Vomiting | Hypokalaemia - reabsorption of bicarbonate

Question 36

What is respiratory failure?

Answer 36

Failure to maintain oxygenation

Question 37

Describe what type 1 respiratory failure is

Answer 37

Hypoxaemia in the absence of hypercapnia Ventilation is normal Distubance of the VQ matching system within the lung

Question 38

What can cause type 1 respiratory failure?

Answer 38

Intrinsic lung disease Acute asthma Lung fibrosis Pulmonary embolism

Question 39

Describe what type 2 respiratory failure is

Answer 39

Hypoxaemia with hypercapnia

Question 40

What might cause type 2 respiratory failure

Answer 40

Sedative overdose Reduced neuomuscular power Resetting of the chemoreceptors that drive ventilation in chronic lung disease (COPD

Question 41

What is the oxyhaemoglobin dissociation curve

Answer 41

The relationship of PO2 to oxygen saturation

Question 42

What shape is the oxyhaemoglobin dissociation curve

Answer 42

Sigma