Lung function tests Flashcards
1
Q
what are lung funtion tests?
A
- Pulmonary function tests are non-invasve that allow us to evaluate monitor and manage
- can measure lung air flow, volumes and rates
- lung volumes and capacities
2
Q
what are the two most common PFTs
A
- PEFR -> use a peak flow meter
- Spirometery
3
Q
what is a peak flow meter
A
- maximal expiration
- blow out as hard as you can
4
Q
what is residual volume
A
after full expiration, you still have some air left in your lungs
4
Q
what is residual volume
A
after full expiration, you still have some air left in your lungs
5
Q
label this graph
A
6
Q
label this diagram
A
7
Q
what does vital capacity rely on
A
- it may be reduced due to to lungs not being fully filled in inspiration
- lungs not fully emptied on expiration
- could be both
- ## can be due to lungs being stiff eg, pulmonary lung fibrosis as a form of interstitial lung disease
8
Q
what is forced vital capacity
A
- during expiration small airways are compressed
- there is a point when no more air can be driven out the alveoli
- ## if expiratory flow is compromised much earlier in expiration then this produces an obstructuve deficit -> Chronic obstructuve lung disease
9
Q
what does it mean if FVC>0.7
and FVC<0.7
A
- FVC<0.7 =obstructive
- FVC>0.7 = restrictive
10
Q
what are some features of obstructive defect
A
- FVC nearly normal in early days but may decrease if there is ari trapping
- FEV1 is reduced
- FEV1/FEV < 0.7
- seen in asthma, COPD, bronchiastasis
11
Q
what are some features of a restrictive defect
A
- TLC is reduced
- FVC is reduced
- FEV1 is reduced proportionately
- FEV1/FVC is normal
- lung fibrosis, interstitual lung disease, myasthenia gravis
12
Q
mild obstructive flow chart
A
13
Q
moderate obstructive flow chart
A
14
Q
restrictive flow limitation
A
- vital capacity is reduced
- FEV1 is reduced
- there is an elevated FEV1 ratio due to reduced complications
15
Q
in which situaton does a bronchodialator help
A
significant improvement in asthma than in COPD
16
Q
label this
A
