Respiratory failure + airways restriction and obstruction

Question 1

How would you measure airways restriction/obstruction and respiratory failure?

Answer 1

ABG (resp failure)

Spirometry (airways restriction/obstruction)

Question 2

What is the spirometry definition of airways obstruction?

Answer 2

FEV1/FVC

Question 3

Give an example of a disease that is characterised by airways obstruction

Answer 3

Asthma (intermittent), COPD (constant), bronchiectasis

Question 4

What is airways restriction characterised by?

Answer 4

Normal or increased FEV1/FVC but decreased FVC

Question 5

Give some examples of diseases characterised by airways restriction

Answer 5

interstitial lung disease (sarcoidosis, idiopathic pulmonary fibrosis, rheumatoid disease, asbestosis), extrinsic allergic alveolitis

Question 6

What characterises Type 1 respiratory failure?

Answer 6

Hypoxia (low PaO2) but normal PaCO2

Question 7

What causes Type 1 respiratory failure?

Answer 7

Hypoventilation, V/Q mismatch, R->L cardiac shunt, abnormal diffusion

Question 8

What defines type 2 respiratory failure?

Answer 8

Hypoxia + hypercapnia (^ PaCO2)

Question 9

What causes type 2 respiratory failure?

Answer 9

Hypoventilation, decreased alveolar ventilation