Pulmonary Function Tests Flashcards Preview

Year 1: Respiratory > Pulmonary Function Tests > Flashcards

Flashcards in Pulmonary Function Tests Deck (15):
1

in spirometry of an asthmatic: FEV1 is _____

reduced

2

in spirometry of an asthmatic: FVC is ______

preserved

3

only situation in which FVC is reduced is when ______

the patient has COPD
(An exception is when asthma has remodelled the airways, causing FVC to decrease).

4

Expiratory flow rate is from TLC to RV. What are the units?

L/s (litres per second)

5

PEFR is _____ in obstructive, and _____ in restrictive

reduced, normal

6

FEV1 is _____ in obstructive, and _____ in restrictive

reduced, reduced

7

FVC is _____ in obstructive, and _____ in restrictive

normal in asthma and reduced in COPD, reduced

8

FEV1/ FVC ratio is _____ in obstructive, and _____ in restrictive

reduced, normal (sometimes high)

9

FEV1 response to B2-agonist is ______ in obstructive, and ______ in restrictive

>15% in asthma and <15% in COPD, no response

10

bronchial challenge testing

using a marker of airway hyper-responsiveness (e.g. histamine). Finding the concentration required to produce a 20% drop in FEV1. Or using allergens/ chemicals to diagnose occupational asthma

11

exercise testing

for asthmatics: they will have decreased FEV1 and decreased PEFR post-exercise.
In Interstitial Lung disease: there is decreased SaO2 during exercise

12

static lung volumes

these are effort independent tests e.g. helium dilution/ N2 washout to find the functional residual capacity.

13

Transfer factor (Diffusing Capacity)

CO's diffusion across alveolar-capillary barrier (AKA single breath diffusing capacity).
TLCO (total lung transfer for CO) is decreased in anaemia (not enough Hb), emphysema (not enough lung tissue - holes), Interstitial lung disease (fibrotic), pulmonary oedema (fluid), pulmonary emboli, bronchiectesis

14

how is airway resistance measured?

whole body plethymography, or (more easily) by impulse oscillometry

15

why is exhaled breath condensate measured?

Exhaled breath NO is a non-invasive marker of eosinophilic airway inflammation in asthma. This is not useful in COPD (NO is supressed by smoking). High NO levels reflect uncontrolled asthmatic inflammation