PFT Testing

Question 0

How many lung volumes are there?

Answer 0

4

Question 1

What are 3 measurement types?

Answer 1

• lung volumes/capacities
• flow rates
• gas diffusion

Question 2

How many lung capacities are there?

Answer 2

4

Question 3

What does one lung capacity equal?

Answer 3

2 or more lung volumes

Question 4

What are the directly measured lung volumes?

Answer 4

• IC
• IRV
• ERV
• VC
• VT

Question 5

What are the indirectly measured lung volumes?

Answer 5

• RV
• FRC
• TLC

Question 6

How do we measure indirect volumes?

Answer 6

Perform a SVC maneuver

Question 7

How would you instruct a patient to perform a SVC?

Answer 7

Take a maximal inspiration followed by a maximal expiration without force

Question 8

What kind of disease will the SVC provide important volumes for?

Answer 8

Restrictive diseases

Question 9

What is the definition of IRV?

Answer 9

Maximum volume of air inspired following normal inspiration. Not clinically significant

Question 10

What is the definition of the ERV?

Answer 10

Normal inhale followed by maximal exhalation (20-25% of VC)

Question 11

What is the definition of IC?

Answer 11

Normal exhalation followed by maximal inhalation

Question 12

What is the definition of VC?

Answer 12

• inspiration: maximal exhalation followed by inhaling deeply as possible
• expiration: maximal inhalation followed by exhaling maximally
• 80% of TLC
• obtained from VC maneuver

Question 13

What is pulmonary mechanics?

Answer 13

• Evaluates lungs ability to move large volumes quickly

- measures FLOWS

Question 14

What disease will FVC provide important flow rates for?

Answer 14

Obstructive

Question 15

How would you instruct a patient to perform a FVC maneuver?

Answer 15

Take a maximal inspiration followed by a maximal expiration as forcefully and rapidly as possible

Question 16

What are some important facts about FVC?

Answer 16

• effort dependent
• must begin exhalation quickly
• exhalation must be > or = to 6 seconds
• should equal SVC
• indicates obstruction if not completed in 3 seconds

Question 17

What is FEF25-75?

Answer 17

Small airways

Question 18

What is FEF200-1200?

Answer 18

Large airways

Question 19

What are some important facts about PEFR?

Answer 19

• effort dependent
• typical value 10 L/sec (600 L/min)
• sometimes used to evaluate asthmatic patients, pre/post bronchodilation
• ID in flow-volume graph as highest point

Question 20

What is FEV/FVC ratio?

Answer 20

FEV for a given interval expressed as a % of a FVC

Question 21

What is FEV1.0?

Answer 21

• volume of gas expired over a given 1 second

- best indicator of obstructive disease

Question 22

What does it mean if your FEV1/FVC ratio <70%?

Answer 22

Obstructive

Question 23

What does it mean if your FEV1/FVC ratio is >70%

Answer 23

Indicates no obstruction so normal or restrictive

Question 24

What is a flow volume loop?

Answer 24

Measures the volumes and flow rates of the FVC

Question 25

What are the directions of a flow volume loop?

Answer 25

- patient performs a FEV from TLC | - followed by a FIV from RV

Question 26

What is measured on the FVC vertical axis?

Answer 26

- flow rates measured directly on the vertical axis - expiratory flows above base line - inspiratory flows below base line

Question 27

What is measured on the FVC horizontal axis?

Answer 27

-volume measured directly on the horizontal axis

Question 28

What would the shape be of a restrictive flow-volume loop?

Answer 28

tall and skinny

Question 29

What would the shape be of an obstructive flow-volume loop?

Answer 29

scooped out

Question 30

What does fixed airway obstruction cause?

Answer 30

equal decreases in both expiratory and inspiratory flow rates

Question 31

How would you know if you had an intrathoracic airway obstruction?

Answer 31

- flattened on expiration | - flow limitation

Question 32

How would you know if you had an extrathoracic large airway obstruction?

Answer 32

flow limitation on inspiration

Question 33

What is the purpose of the pre and post bronchodilator PFT testing?

Answer 33

used to measure the reversibility of an obstructive pattern

Question 34

A bronchodilator post study is considered to be significant with an increase in how much?

Answer 34

15% or more

Question 35

When should all bronchodilator therapy be held?

Answer 35

8 hours prior to testing

Question 36

What is bronchial provocation?

Answer 36

looks for airway reactivity

Question 37

What are some ways bronchial provocation is done?

Answer 37

- methacholine challenge - histamine challenge - cold air challenge - exercise challenge

Question 38

How is it determined that a patient has reactive airways after bronchial provocation?

Answer 38

a 20% or more decrease in FEV1 occurs