Exam 2: Pulmonary Function Test

Question 1

What do pulmonary function tests (PFTs) measure?

Answer 1

Evidence of respiratory dx with respiratory symptoms (e.g. dyspnea, cough, cyanosis, wheezing, etc.)
Assess for progression of lung disease
Monitor the efficacy of a given treatment
Evaluate patients pre-operatively
Monitor for potentially toxic side effects of certain drugs

Question 2

What are some common respiratory symptoms that may indicate the need for a PFT?

Answer 2

• Dyspnea
• Cough
• Cyanosis
• Wheezing

Question 3

What is the purpose of conducting pulmonary function tests?

Answer 3

• Look for evidence of respiratory disease
• Assess for progression of lung disease
• Monitor treatment efficacy
• Evaluate patients pre-operatively
• Monitor for toxic side effects of drugs

Question 4

What does ERV stand for in pulmonary function tests?

Answer 4

Expiratory reserve volume: the max volume of air that can be exhaled from the end-expiratory position

Question 5

What is the definition of Total Lung Capacity (TLC)?

Answer 5

The volume in the lungs at maximal inflation, the sum of vital capacity (VC) and residual volume (RV)

Question 6

What does VC stand for in the context of lung volumes?

Answer 6

Vital capacity: the volume of air breathed out after the deepest inhalation

Question 7

What is the formula for Inspiratory Capacity (IC)?

Answer 7

IRV + TV (Total air that can be inspired)

Question 8

What is Forced Vital Capacity (FVC)?

Answer 8

Vol of air exhaled after maximal inhalation

Question 9

What is the significance of the FEV1/FVC ratio?

Answer 9

It indicates lung disease; normal is about 80%

Question 10

What FEV1/FVC ratio suggests obstructive lung disease?

Answer 10

FEV1/FVC < 80%

Question 11

What pattern is indicated by decreased FEV1, normal or decreased FVC, and decreased FEV1/FVC?

Answer 11

Obstructive Pattern

Question 12

What condition is suggested by an increase in FEV1 by 12% after bronchodilator use?

Answer 12

Asthma

Question 13

What characterizes a restrictive pattern in PFTs?

Answer 13

• Decreased TLC
• Decreased FEV1
• Decreased FVC
• Normal FEV1/FVC
• Low DLCO

Question 14

What does DLCO measure?

Answer 14

Diffusion capacity for carbon monoxide

Question 15

What is the normal range for FEV1/FVC ratio?

Answer 15

About 80%

Question 16

What does an FEV1 of 80-100% predicted indicate?

Answer 16

Mild obstruction (Stage 1)

Question 17

What does an FEV1 of <30% predicted indicate?

Answer 17

Very severe obstruction (Stage 4)

Question 18

What TLC percentage indicates restrictive disease according to ATS criteria?

Answer 18

TLC < 80%

Question 19

What TLC percentage range indicates mild restrictive disease?

Answer 19

70-80% predicted

Question 20

What TLC percentage indicates moderate restrictive disease?

Answer 20

60-70% predicted

Question 21

What TLC percentage indicates severe restrictive disease?

Answer 21

<50% predicted

Question 22

What does TLC >120% indicate?

Answer 22

Hyperinflation

Question 23

Residual Volume (RV)

Answer 23

The volume of air remaining in the lungs after a maximal exhalation (prevents lung collapse).
- vol that you cannot access with normal breathing

Question 24

Inspiratory Reserve Volume (IRV)

Answer 24

The maximum amount of air that can be inhaled beyond a normal breath.

Question 25

Tidal Volume (TV)

Answer 25

The volume of air inhaled and exhaled during normal breathing.

Question 26

Functional Residual Capacity (FRC)

Answer 26

ERV + RV (Air left in the lungs after normal exhalation)

Question 27

Forced Expiratory Volume (FEV)

Answer 27

Vol of air exhaled in one breath - the forced expiratory volume in one second is FEV1,

Question 28

restrictive lung disease typically has normal or increased

Answer 28

FEV1/FVC

Question 29

Obstructive Lung Disease Flow Volume Loop (Green)

Answer 29

-Scooped-out/concave expiratory curve due to airway obstruction. -Peak flow is reduced (decreased airflow). -Lung volumes may be increased due to air trapping/hyperinflation. -TLC may be higher (>120% predicted). -FEV₁ is significantly reduced, leading to a low FEV₁/FVC ratio (<70%). -Shift to L, smaller - Airflow obstruction--> prolonged and reduced expiration, leading to air trapping and difficulty exhaling

Question 30

Restrictive Lung Disease Flow Volume Loop (Blue)

Answer 30

Overall loop is smaller in size (due to reduced lung volumes). - FEV₁ and FVC reduced - FEV₁/FVC ratio remains normal or increased. -Peak expiratory flow may be near normal but TLV is significantly lower. -TLC is reduced (<80% predicted). -Flow volume loop generally normal in appearance, but has low lung volumes (shorter in time &vol) -Shift to R

Question 31

Flow Volume Loop

Answer 31

spirometry to diagnose and differentiate between obstructive and restrictive lung diseases Looks at flow vs volume Bottom of curve = inspiration Top of curve = exhalation Normal = upside down ice cream cone shape

Question 32

Memorize Flow Volume Loops/Differentiate on Pic

Answer 32

See Pic

Question 33

Obstructive Diseases

Answer 33

asthma, chronic bronchitis, or emphysema

Question 34

Restrictive Diseases

Answer 34

interstitial lung disease, severe skeletal abnormalities, or diaphragmatic paralysis