respiratory tests

Question 1

what are effort dependant tests?

Answer 1

-forced expiratory volumes/flow rates - spirometry

Question 2

what are effort independent tests?

Answer 2

-relaxed vital capacity - spirometry

other tests not involving forced expiration

Question 3

what are gas diffusion tests?

Answer 3

• CO transfer factor
• arterial blood gases
• Sa02 during exercise

Question 4

what is the difference between asthma and COPD in terms of FVC?

Answer 4

COPD do not reach normal FVC, it is reduced.

Asthma usually does get to the normal FVC, it just has a smaller FEV1 than normal

Question 5

what can you determine from a flow-volume curve?

Answer 5

• peak expiratory flow rate (PEF) (expressed in L/min)

- forced expiratory flow rate between 25 and 75 % of FVC (FEF25-75%)

Question 6

Describe the PEFR, FEV1, FVC, FEV1/FVC ratio, DLCO and FEV1 response to B2 agonist in asthma

Answer 6

PEFR - decreased
FEV1 -decreased
FVC -normal
FEV1/FVC ratio- less than 75%
DLCO - normal
FEV1 response to B2 agonist - greater than 15%

Question 7

Describe the PEFR, FEV1, FVC, FEV1/FVC ratio, DLCO and FEV1 response to B2 agonist in COPD

Answer 7

PEFR -decreased
FEV1 -decreased
FVC - decreased
FEV1/FVC ratio - less than 75%
DLCO - reduced in emphysema
FEV1 response - less than 15%

Question 8

Describe the PEFR, FEV1, FVC, FEV1/FVC ratio, DLCO and FEV1 response to B2 agonist in restrictive disease.

Answer 8

PEFR -normal
FEV1 - decreased
FVC - decreased
FEV1/FVC ratio - greater than 75% (normal)
DLCO - decreased
FEV1 response - no response

Question 9

what is DLCO?

Answer 9

• diffusion capacity of carbon monoxide
• measures gas diffusion across alveolar-arteriolar barrier.
• a decrease in DLCO may be due to anaemia, emphysema, interstitial lung disease, pulmonary oedema and pulmonary emboli.