Pumonary Function Testing

Question 1

Effort dependent tests

Answer 1

Forced expiratory volumes

Flow rates - spirometry

Question 2

Effort independent tests

Answer 2

Relaxed vital capacity - spirometry
Helium/N2 washout static lung volumes
Whole body plethysmography
Impulse oscillometry
exhaled breath nitric oxide

Question 3

Gas diffusion tests

Answer 3

CO transfer factor
Arterial blood gases (resting)
SaO2 during exercise

Question 4

Dynamic Lung Volumes (spirometry)

Answer 4

Volume (l) vs Time (s) curve

Forced expiratory manoeuvre from TLC to RV

Forced Expiratory Volume in 1 second FEV1 (l)

Forced vital capacity FVC (l)

Forced expiratory ration FER (FEV1/FVC ratio)

Relaxed vital capacity RVC

Question 5

Volume dependent expiratory airway closure

Answer 5

asthma

chronic bronchitis

Question 6

pressure dependent expiratory airway closure

Answer 6

emphysema

Question 7

Obstructive Statistics

Answer 7

PEFR = lower
FEV1 = lower
FVC = normal (asthma)
= lower (COPD)
FEV1/FVC = <75%
FEV1 response to B2 agonist = >15% (asthma)
= <15% (COPD)

Question 8

Restrictive Statistics

Answer 8

PEFR = normal
FEV1 = lower
FVC = lower
FEV1/FVC = >75% 
FEV1 response to B2 agonist = no response

Question 9

bronchial challenge tests

Answer 9

exercise

methacholine/histmaine/mannitol

• airway hyper-responsiveness marker
• concn to produce 20% - lower FEV1

allergens/chemicals

• early + late response
• diagnosis of occupational asthma

Question 10

exercise testing

Answer 10

lower FEV1/PEF post exercise = asthma
lower SaO2 during exercise in interstitial lung disease - monitor treatment response

full cardiopulmonary exercise tests

• differentiate cardiac vs respiratory dyspnoea
• heart rate vs O2 uptake vs ventilatory rate

Question 11

static lung volumes

Answer 11

effort independent tests
helium dilution/ N2 washout: functional residual capacity
RV = FRC - ERV
TLC = VC + RV
increase TLC = hyperinflation (emphysema)
decrease TLC = restrictive lung disease
gas trapping in COPD:
(RV/TLC%)
(RVC-FVC/RVC%)
TLC adds little to RVC + FVC

Question 12

Transfer Factor

Answer 12

CO diffusion across capillary barrier

TLCO = total lung transfer for CO

Question 13

TLCO

Answer 13

total lung transfer of CO

Question 14

lower TLCO

Answer 14

anemia
emphysema
int lung disease
pulmonary oedema
Po emboli
Bronchiectasis

Question 15

when is transfer factor used

Answer 15

monitor treatment in Int lung disease

Question 16

How is airway resistance measured

Answer 16

whole body plethysmography

impulse oscillometry