Ch. 4

Question 1

What are the normal values for diagnosing pulmonary disease?

Answer 1

> 80% - <100%

Question 2

All methods use what _______ .

Answer 2

CO

Question 3

What is used to assess gas exchange and estimate lung volumes?

Answer 3

DLCO

Question 4

What is DLCO?

Answer 4

Measures the diffusion of CO across the alveolar capillary membranes.

Question 5

Why do we use DLCO?

Answer 5

Because carbon monoxide adheres to hemoglobin approximately 210 times more readily than O2.

Question 6

Significant ⬇️ of CO in exhaled example w/diffused 80% or more indicates what?

Answer 6

Good gas exchange

Question 7

If the measurements are the same or similar (diffused < 80%) what does that indicate?

Answer 7

Limited gas exchange

Question 8

What are the 3 types of DLCO?

Answer 8

DLCOsb - single breath (most commonly used)
DLCOrb - restricted breath (research)
DLCOib - intrabreath (exercising)

Question 9

How long do you hold DLCOsb?

Answer 9

10 sec

Question 10

DLCOsb is good for everything except?

Answer 10

Exercise

Question 11

DLCO will be inc. during exercise due to?

Answer 11

Inc. temp, ventilation, and flow.

Question 12

DLCO is very sensitive to?

Answer 12

Distribution of ventilation and V/Q mismatch

Question 13

Causes of V/Q mismatch?

Answer 13

Anything that hinders the body’s ability to deliver enough oxygen to your bloodstream.
• COPD exacerbation
• asthma
• pneumonia
• chronic bronchitis
• pulmonary edema
• airway obstruction
• PE
• OSA

Question 14

What is HB?

Answer 14

Protein molecule in RBCs that carries oxygen from lungs to tissues, and returns CO2 to the body.

Question 15

What are the ranges for hemoglobin?

Answer 15

13.5 - 17.5 (M)
12 - 15.5 (F)

Question 16

How much does the machine use for males and females?

Answer 16

14.6% (M)
13.4% (F)

Question 17

Low HB reduces ______ because there is not enough to carry and pick up ____ .

Answer 17

DLCO; CO

Question 18

What is COHB?

Answer 18

Stable complex of CO that forms in RBCs when CO is inhaled

Question 19

What are the percentages for COHB?

Answer 19

<3% for non smokers
4-10% smokers
> 50% fatal
Machine consumes 2%

Question 20

When a patient smokes before the test or is a heavy smoker they will have?

Answer 20

An inc. COHB

Question 21

The amount of time to defuse the increase in CO will take longer than the predicted______ sec.

Answer 21

10

Question 22

If you make adjustments for elevated CO______ would be higher because it reduces the value of the predicted values.

Answer 22

DCO

Question 23

How do you perform a DLCOsb?

Answer 23

1. patient breathes normal VT to establish baseline
2. exhale to RV
3. inhales to max RV and hold for 10 seconds
4. inhale special gas mixture from reservoir or spirometer.
5. tracer gas 0.3%, CO, 21%, O2, N2, CH4 or Ne
6. exhales to RV
7. basically in SVC w/10 second breath hold

Question 24

If you have a leak, your DLCO will be ______?

Answer 24

Increased

Question 25

The ______ method measures breath hold from _____ of the Ti to the midpoint of the alveolar sample.

Answer 25

Jones; 0.3

Question 26

All DLCO must be corrected to?

Answer 26

STPD (standard temp (0.C) and standard pressure (760 mmHg absolute) dry no H2O content.

Question 27

Temperature, pressure, volume, and condensation, will all be?

Answer 27

Increased

Question 28

All measurements are reported at ______?

Answer 28

BTPS (Body, temp, pressure, sats)

Question 29

BTPS presume the combined environmental circumstances of a body temperature of______ PB of ________ mmHg breathing sats w/water vapor (=100% relative humidity).

Answer 29

37 degrees C; 700

Question 30

For acceptable results you need…..

Answer 30

• average of two best tests (no more than 5) • Tests must be acceptable & replicable • results must be within 3mL/CO/min/mmHg

Question 31

Decrease in DLCO <80% means what?

Answer 31

• poor gas exchange • restrictive or obstructive • sarcoidosis • scleroderma • cystic fibrosis • emphysema

Question 32

An increase in DLCO is associated with circumstances which there was an increase in _____ binding sites for _____ uptake.

Answer 32

HB;CO

Question 33

What are diseases that will have an increase DLCO

Answer 33

• Polycythemia • Alveolar hemorrhage

Question 34

DLCO will always be increased during?

Answer 34

Exercise testing

Question 35

What do we do for an obstruction?

Answer 35

We look at DLCO to determine severity of gas exchange and emphysema

Question 36

Which obstructive disease is low?

Answer 36

Emphysema **CBABE** ***All other obstructive diseases are normal***

Question 37

What do we do for a restriction?

Answer 37

Look at DLCO to see if restriction is interstitial or extrastitial

Question 38

DLCO < 80% means?

Answer 38

Restriction is happening inside lungs

Question 39

A normal DLCO means what?

Answer 39

Restriction is happening outside the lungs

Question 40

In mix defect defining ______ in the DLCO can be very _____.

Answer 40

Decrease;difficult

Question 41

We won’t know if the disease is ______ or ______.

Answer 41

Restrictive or obstructive

Question 42

Mixed defect relies on the patients…..?

Answer 42

• history • work environment • medical data (x-rays, lab, previous diagnosis)

Question 43

What is mixed defect used for?

Answer 43

To come up with a hypothesis or a possible diagnosis