Random Resp Questions

Question 1

What is normal PaO2?

Answer 1

10.5 - 13.5 pKa

Question 2

What is normal PaCO2?

Answer 2

4.8 - 6.0 pKa

Question 3

What is the PaO2 and PaCO2 level in type I respiratory failure?

Answer 3

PaO2 is < 8 pKa

PaCO2 is normal or low (below 4.8)

Question 4

What is the PaO2 and PaCO2 level in type II respiratory failure?

Answer 4

PaO2 is usually low (hypoxaemia) (< 10.5)

PaCO2 is > 6.5 pKa

Question 5

How can hypoxaemia be corrected?

Answer 5

By small increases in FIO2 (fraction of inspired air which is oxygen) which increases PAO2 in poorly ventilated alveoli, thus increasing diffusion rate

Question 6

What is shunt?

Answer 6

Blood passing from R to L side of heart without contacting ventilated alveoli therefore not taking part in gas exchange

Question 7

What is deep vein thrombosis (DVT)?

Answer 7

When thrombus forms in the venous system, usually in the deep veins of legs

Question 8

What is pulmonary embolism (PE)?

Answer 8

Acute disease when thrombus forms in the deep veins of the legs, dislodges and embolises to pulmonary arteries

Question 9

What is venous thromboembolism (VTE)?

Answer 9

A disease that includes both deep vein thrombosis (DVT) and pulmonary embolism (PE)

Question 10

What is pulmonary hypertension?

Answer 10

A chronic disease where blood pressure is elevated in the pulmonary arterial tree. Defines by mean pulmonary artery pressure of >25mmHg.

Question 11

What is a pleural effusion?

Answer 11

Collection of fluid in pleural space

Question 12

What is a pneumothorax?

Answer 12

Collection of air in the pleural cavity

Question 13

What is a hydropneumothorax?

Answer 13

The collection of both air and water in the pleural cavity

Question 14

What is mesothelioma?

Answer 14

Primary pleural malignancy

Question 15

What is empyema?

Answer 15

Pus in the pleural space

Question 16

What is a haemothorax?

Answer 16

Blood in the pleural space

Question 17

Give examples of pleural disease

Answer 17

Pleural effusion (most common), pneumothorax, hydropneumothorax, mesothelioma, empyema, haemothorax

Question 18

What is COPD

Answer 18

Chronic obstructive pulmonary disease, includes chronic bronchitis and emphysema

Question 19

What is chronic bronchitis?

Answer 19

Cough productive of sputum most days in at least 3 consecutive months for 2 or more consecutive years

Question 20

What FEV1:FVC ratio is considered obstructive?

Answer 20

<0.7

Question 21

What is a bulla?

Answer 21

Abnormal emphysematous air space in the lung greater than 1cm diameter. Patient with a bulla should avoid air travel. Called bleb if less than 1cm diameter or if under the pleura

Question 22

What is asthma?

Answer 22

A disease characterised my increased responsiveness of trachea and bronchi to various stimuli manifested by widespread narrowing or airways that changes in severity spontaneously/ as a result of therapy. Characteristics are wheezing, panting/gasping, variability

Question 23

Where are central chemoreceptors located?

Answer 23

Medulla

Question 24

Where are peripheral chemoreceptors located?

Answer 24

Carotid and aortic bodies

Question 25

What do central chemoreceptors respond to?

Answer 25

Respond directly to changes in hydrogen ion concentration, detect changed in arterial partial pressure of CO2 (PCO2)

Question 26

What do peripheral chemoreceptors respond to?

Answer 26

Primarily respond to PO2 (less to PCO2) and plasma (H+)

Question 27

What is the primary ventilatory drive?

Answer 27

Central chemoreceptors

Question 28

What is the secondary ventilatory drive?

Answer 28

Peripheral chemoreceptors

Question 29

What is fibrosis?

Answer 29

Increased thickening of the alveolar membrane, decreased gas exchange

Question 30

What is oedema?

Answer 30

Fluid in the interstitial space increasing the diffusion distance

Question 31

What is emphysema?

Answer 31

Air spaces become bigger than normal, distal to the terminal bronchiole arising either from dilatation or from destruction of their walls and without obvious fibrosis Reduced SA for gas exchange Easy to get air in but elasticity lost

Question 32

What values cannot be measured by spirometry?

Answer 32

RV, TLC and FRC cannot be measured by spirometry

Question 33

What is pulmonary (minute) ventilation?

Answer 33

Total air moving in and out of the lungs

Question 34

What is alveolar ventilation?

Answer 34

Fresh air moving into the alveoli and therefore available for gas exchange (more significant)

Question 35

What has an impact on alveolar ventilation?

Answer 35

Anatomical dead space

Question 36

Where is alveolar ventilation highest?

Answer 36

At the base of the lung are the lungs where compliance is highest due to the lungs being slightly compressed by the diaphragm

Question 37

What is infant respiratory distress syndrome?

Answer 37

Insufficient surfactant production

Question 38

Where is intrapleural pressure lowest (most negative)?

Answer 38

At the apex of the lung, least negative at base due to gravity pulling down the lung

Question 39

What is anaemia?

Answer 39

Defined as any condition where O2 carrying capacity of the blood is compromised and is decreased

Question 40

Does anaemia affect the oxyhemoglobin binding curve?

Answer 40

No, the oxyhemoglobin binding curve is unaffected in anaemia

Question 41

What is Nitrous oxide used for in ventilation?

Answer 41

A common sedative/ light anaesthetic agent, blunts peripheral chemoreceptors response to falling PaO2. Problematic if given t hypoxia patients and can aggregate their situation

Question 42

What do barbiturates and opioids do in ventilatory control?

Answer 42

Depress the respiratory centres, overdoses often cause death due to respiratory failure. Decrease sensitivity to pH and decrease peripheral chemoreceptors response to decreased PO2, respond to PCO2

Question 43

What is the main function of CFTR?

Answer 43

Transport of Cl ions from the interstitium into the airway lumen

Question 44

The activation of which channel results in a reduction in airway surface liquid (ASL) volume?

Answer 44

ENaC

Question 45

What does standing up do?

Answer 45

Decreases EDV, preload, SV, CO & MAP

Question 46

What is normal FEV1?

Answer 46

3.5 - 4L

Question 47

What is normal FVC?

Answer 47

5L

Question 48

What is a normal FEV1:FVC ratio?

Answer 48

0.7-0.8

Question 49

Characteristics that would define fluid as an exudate

Answer 49

Protein - pleural fluid/ serum fluid ration > 0.5 LDH - pleural fluid/ serum fluid ration > 0.6 Pleural fluid LDH >2/3rd ULN serum LDH

Question 50

Are exudates or transudates mostly caused by pulmonary causes?

Answer 50

Exudates