Spirometry

Question 1

What is seen in an obstructive picture?

Answer 1

FEV1 is reduced <80%

FVC is reduced but not as much, so the FEV to FVC ratio is reduced

Question 2

What is seen in a restrictive picture?

Answer 2

Both FEV and FVC are reduced, so the RATIO is normal

Question 3

What are the stages of COPD and what can it be useful for?

Answer 3

FEV1 stage 1 … 70% or above

Stage 4 - 30% or below

Question 4

What is FEV1?

Answer 4

The forced expiratory volume - how much air you can breathe out after maximal inhalation within 1 second

Question 5

What is FVC?

Answer 5

The maximum out of air you can breathe out after maximal inhalation in a timed setting

Question 6

What is the normal FEV1 to FVC ratio?

Answer 6

Normally, FEV1 is about 80% of the FVC

Question 7

What happens to the FEV1 in obstructive lung disease?

Answer 7

In obstructive lung disease, there is a problem getting the air OUT the lung, so FEV1 is greatly reduced.

Question 8

What happens to the FVC in obstructive lung disease?

Answer 8

The FVC is also reduced, but to a less extent than the FEV1

Question 9

What happens to the FEV1 to FVC ratio in obstructive lung disease?

Answer 9

Overall reduced

Question 10

How do you diagnose obstructive lung diseases (from lung function tests)? (Which two things do you look at)

Answer 10

FEV1 to FVC ratio - reduced below 70%

Assess severity by looking at FEV1 alone

Question 11

What happens to the FEV1 in restrictive lung disease?

Answer 11

In restrictive disease, there is a problem with getting air IN. So as you have less air inhaled to begin with, the FEV1 exhalation will also be reduced, but to a less extent than FVC reduction.

Question 12

What happens to the FVC in restrictive lung disease?

Answer 12

In restrictive disease, there is a problem with getting air IN. So as you have less air inhaled to begin with, so FVC is greatly reduced.

Question 13

What happens to the FEV1 to FVC ratio in restrictive lung disease?

Answer 13

Could be normal, or could be increased if the denominator (FVC) is smaller than the numerator (FEV1)

Restrictive lung disease RAISES the ratio or makes it REMAIN normal

Question 14

How do you assess severity of restrictive lung disease?

Answer 14

Look at TLC but also look at all volumes as they will all be low

Question 15

Once you have diagnosed obstructive lung disease (FEV1/FVC <80), how do you distinguish between asthma and COPD?

Answer 15

Give bronchodilators and repeat the tests, if FEV1 is greatly increased, it’s reversible obstruction

Question 16

What do you see in a mixed (restrictive and obstructive) lung disease picture?

Answer 16

Low total lung capacity (restrictive)

Low FEV1/FVC ratio as well (obstructive)