B4.37 - Evaluating Pulmonary Function Tests

Question 1

Indications for PFT

Answer 1

Screening

Evaluation of respiratory symptom or sign

Grading severity of respiratory disease

Following progression of respiratory disease

Monitoring response to therapy

Monitoring occupational, drug or radiation toxicity

Predicting prognosis

predicting post op pulmonary risk

assessing disability/impairment

Question 2

what does spirometry measure

Answer 2

how fast and much you air you breath out

Question 3

what are teh ATS acceptability criteria for FVC

Answer 3

Good start of test

Smooth continuous curve

Satisfactory exhalation

Question 4

what determines if the start of the test was good enough

Answer 4

extrapolated voluem <5% of FVC or 150 mL

Question 5

what is the minimun time an exhalation must be for it to be acceptable

Answer 5

6 seconds

10 is prefered

Question 6

what are ATS reproducability criteria for FVC

Answer 6

after 3 acceptable maneuvers, the two largest FVC adn FEV1 are within i150 mL of each other

Question 7

what is depicted her

Answer 7

excellent effort

the goal

Question 8

what is depicted here

Answer 8

hesitating start

Question 9

what is depicted here

Answer 9

submaximal effort

Question 10

what is depicted here

Answer 10

rainbow curve

normal in young, non smoking females

Question 11

Answer 11

early termination

Question 12

Answer 12

coughing

Question 13

Answer 13

subject briefly stopped exhaling

Question 14

Answer 14

the “knee”

normal in young non smokers

Question 15

what are gas dilution methods

Answer 15

nitrogen washout and helium dilution

takes advantage of inert, poorly soluble gas of known concentration

a way to measure lung volume

Question 16

what is a non gas way of measuring lung volume

Answer 16

body box

Question 17

equation for Vf (unknown lung volume)

Answer 17

Vf = (change in V/change in P) (PB)

Question 18

what is TLC

Answer 18

total lung capacity

FRC + IC

or

RV + VC

Question 19

what is RV

Answer 19

residual volume

FRC - ERV

Question 20

what is the reference equation used for finding reference ranges for spirometry

Answer 20

from NHANESIII

FEV1 - 80-120

FVC - 80-120

Question 21

what is an obstructive pulmonary defect

Answer 21

a disporportionate reduction of maximal airflow from the lung with respect to the maximal volume (FVC) that can be displaced from the lung. Indicates expiratory airlow limitation

Question 22

what is a normal FEV/FVC

Answer 22

>.7 is the cutoff for normal

Question 23

what do these indicate and why

Answer 23

Obstructive pulmonary defect

because the FEV1/FVC ration is low and expiratory phase of flow/volume loop is lower than expected indicating an issue with exhalation

Question 24

causes of obstructive pulmonary defect

Answer 24

Asthma

COPD

bronchiectasis

Obliterative bronchiolitis

LAM

Diffues panbronchiolitis

Question 25

what is restrictive pulmonary defect

Answer 25

characterized physiologically by reduction in TLC below the 5th percentile of normal distribution.

Question 26

what can a restrictive pulmonary defect be inferred

Answer 26

when theres FVC that is reduced and FEV1/FVC ration is nromal or increased.

Question 27

what does this demonstrate

Answer 27

restrictive pulmonary defect Note: normal FEV1/FVC ration Narrower exhalation because of reduced overall volume

Question 28

what are restrictive defects in the lung

Answer 28

resection atelectasis stiff lung (fibrosis) CHF Thickened pleura tumor

Question 29

what are restrictive defects in the pleual cavity

Answer 29

effusion enlarged heart tumor

Question 30

what are restrictive defects in the chest wall

Answer 30

scleroderma ascites pregnancy obesity kyphoscoliosis splinting due to pain

Question 31

what are restrictive defects in muscle

Answer 31

neuromuscular disease old polio paralyzed diaphragm

Question 32

what is a mixed pulmonary defect

Answer 32

coexistence of obstruction and restriction defined physiologically when both the FEV1/FVC ratio and the TLC are decreased

Question 33

what are the categories of severity of spirometric abnormalities

Answer 33

Question 34

what is a bronchodilator response

Answer 34

usually four separate doses of albuterol is given by metered dose inhaler using a space. Tests repeated after 15 minute delay a \>12% and 200mL increased in FEV1 or FVC meets critera for bronchodilator response

Question 35

can you differentiate asthma and COPD with a bronchodilator response

Answer 35

no bitch

Question 36

differentiate between extrathoracic, intrathoracic, varable and fixed airway obstructions

Answer 36

extrathoracic - above suprasternal notch intrathoracic - between suprasternal notch and carina Variable - lesion narrows and decreases flow excessively during one phase of respiration fixed - narrowing causes decreased flow equally during both phases of respiration

Question 37

examples of variable extrathoracic lesions

Answer 37

vocal chord paralysis/dysfunction tracheomalacia goiter

Question 38

examples of variable intrathoracic lesions

Answer 38

traheomalacia malignant tracheal lesions tracheal stricture

Question 39

fixed lesions

Answer 39

tracheal stenosis vocal cord paralysis vocal cord malignancy

Question 40

name the type of obstruction

Answer 40

variable extrathoracic

Question 41

name the type of obstruction

Answer 41

variable intrathoracic

Question 42

name the obstruction

Answer 42

fixed major airway obstruction