Diagnostics: PFT

Question 1

Most accurate measure of Pulmonary fxn

Answer 1

Pleth Box

Question 2

Signs of Air Trapping/Pseudorespiration

Answer 2

Decreased FVC, Increased TLC

Question 3

Three types of pulmonary fxn testing?

Answer 3

Spirometry Lung Volumes Diffusing Capacity

Question 4

Types of Spirometry tests

Answer 4

Methacholine Cronchodilator Challenge Neuromuscular Protocol

Question 5

Types of Lung Volume Tests

Answer 5

Helium dilution Nitrogen washout Plethysmography

Question 6

Why do PFTs?

Answer 6

Explain Dyspnea, hypoxemia Objectively Follow Disease Pre-Op Exams

Question 7

Total Lung Capacity =

Answer 7

Inspir. Reserve + Tidal + Expiratory Reserve + Residual

Question 8

Vital Capacity =

Answer 8

Insp. Reserve + Tidal + Exp. Reserve

Question 9

Functional Residual Capacity =

Answer 9

Expiratory Reserve Vol + Residual Vol.

Question 10

What do patients do in spirometry?

Answer 10

Maximal breath to TLC, then blows out as hard/fast as possible

Question 11

Name for total volume expired in a spirometry test

Answer 11

Forced Vital Capacity

Question 12

Name of the volume expired in the first second of a spirometry test?

Answer 12

FEV1

Question 13

Most reproducible measure of flow rate over time

Answer 13

FEV1

Question 14

In PFTing curves, the portion above the axis is _______ and the portion below the axis is ______

Answer 14

Exhalation Inhalation

Question 15

Criteria for an acceptable PFT?

Answer 15

Smooth, Continuous curve Good Start Finish w/ plateau for 1 sec

Question 16

Obstructive pattern should make you suspect…

Answer 16

Asthma, emphysema, Chronic Bronchitis

Question 17

Restrictive pattern of PFT should make you suspect…

Answer 17

Pulm. fibrosis, Hypersensitivity pneumonitis, sarcoidosis, silicosis, neuromuscular probs

Question 18

What happens in an extrathoracic resp probs

Answer 18

Closure on insp. Opening on expiration (Flat on bottom of loop) Example – Laryngeal Cancer, Vocal Cord Adduction

Question 19

What happens in intrathoracic resp probs

Answer 19

Open on inspiration, Closure on expiration (Flat on top, normal curve below)

Question 20

If no confidence intervals are given, what is the cutoff for diagnosing an obstruction?

Answer 20

70% FEV1/FVC Look for a scooped loop

Question 21

With an FEV1/FVC ration below 70%, you determine the patient has an obstructive disease. They have a normal FVC. What do you assess next?

Answer 21

Post-dilator FEV1 and FVC. If Albuterol fixes it, its Asthma. If not, its COPD

Question 22

How do you distinguish which type of COPD you have?

Answer 22

DLCO Down in emphysema Normal in Chronic bronchitis

Question 23

How do you determine is a restrictive lung disease patient has a parenchymal or extrapulmonary restriction?

Answer 23

DLCO Down in parenchymal Normal in extrapulmonary

Question 24

Sign of a positive bronchodilator change

Answer 24

FEV1 or FVC increase of 12% AND absolute chance of 200 mL after bronchodilaton

Question 25

In mathacholine testing, a FEV1 drop of ______ at a low concentration is diagnostic of hyperresponsiveness

Answer 25

more than 20%

Question 26

Neuromuscular disease presents as...

Answer 26

Restriction

Question 27

What do you do in neuromuscular testing

Answer 27

Assess resp. muscle strength (make patient forcibly inhale/exhale against a closed mouthpiece attached to a pressure gauge).

Question 28

Normal Max Inspiratory Pressure? Expiratory?

Answer 28

Insp. -- 65 Expiratory -- 80

Question 29

Normal Maximal Voluntary Ventillation

Answer 29

Normal is FEV1 x 35

Question 30

How does a Helium Dilution test work?

Answer 30

Known volume of inert gas (He) at a known concentration is inhaled. Gas is diluted by air volume already in lungs. Concentration of exhaled gas is measured, reflects the initial volume of gas in the lungs.

Question 31

How does a Nitrogen Washout test work?

Answer 31

Put a person on 100% Oxygen, measure the amount of Nitrogen being released with their breaths over time.

Question 32

What happens in plethysmography?

Answer 32

Subject makes an inspiratory effort against a closed airway, which increased the volume of the lung. Airway pressure decreases and the box pressure increases. Use P1V1=P2V2

Question 33

Volume measured by He dilutiona nd Nitrogen washout?

Answer 33

Functional Volume Does NOT measure areas with Trapped Gas Inaccurate in severe obstructive lung disease

Question 34

What are you learning in a DLCO test?

Answer 34

The amoutn of gas that is able to diffuse across the alveolar-capillary membrane

Question 35

How do you measure diffusing capacity?

Answer 35

Inhale known conc. of CO + Helium to TLC. Hold breath for 10 seconds Exhale and measure the CO and Helium in expired gas

Question 36

Main determinants of diffusing capacity?

Answer 36

Surface Area Capillary Flow Membrane Diffusing Capacity (kCO)

Question 37

DLCO =

Answer 37

KCO X VA

Question 38

In a patient with normal lung volumes and spirometry, a low DLCO indicates...

Answer 38

Pulmonary vascular disorder.

Question 39

Interpret

Answer 39

Normal PFT

Question 40

Interpret

Answer 40

PFT Obstructive

Question 41

Intrepret

Answer 41

PFT - Restrictive

Question 42

Fixed, Variable Extrathoracic, or Variable Intrathoracic?

Answer 42

Fixed

Question 43

Fixed, Variable Extrathoracic, or Variable Intrathoracic?

Answer 43

Variabe Extrathoracic

Question 44

Fixed, Variable Extrathoracic, or Variable Intrathoracic?

Answer 44

Variable Intrathoracic