Exam 3 - Lecture 2

Question 1

Flow volume loops are most focused on

Answer 1

maximal peak expiratory force during expiration

Question 2

How is maximal peak expiratory force measured?

Answer 2

During FVC maneuver (from TLC to RV with max effort)

Question 3

Flow rate is on the _ axis and lung volume is the _ axis

Answer 3

Y;X

Question 4

What do these flow volume loops often lack?

Answer 4

Don’t give a “zero” or standard axis, just a rough liter scale.

Question 5

Depending on the machine, you may not get exact _____

Answer 5

values for RV or TLC

Question 6

On flow volume loops, what are the results of restrictive disease?

Answer 6

low lung volume with less air to exhale = lower peak expiratory flow rate

Question 7

What is restrictive disease more prone to and why?

Answer 7

Low lung volume raises airway resistance, which also results in more narrow airways, so its EASIER TO COLLAPSE

Question 8

In restrictive lung disease, expiratory flow rate is limited NOT by _____, but by _______

Answer 8

People often think OBSTRUCTION, but its due to lung emptiness.

Question 9

What is the specific reason for decreased lung volumes in restrictive disease?

Answer 9

more elastic tissue

Question 10

During expiration in obstructive disease, the airway _____ which leads to increased RV

Answer 10

collapses, retaining air

Question 11

On the flow volume loop with obstructive disease, the loop shape is _____ due to small airway collapse.

Answer 11

Scooped/concave

Question 12

In obstructive disease such as emphysema/COPD, elastic tissue is reduced, which increases ______

Answer 12

compliance

Question 13

Elastic tissue/recoil and compliance have a _______ relationship.

Answer 13

Inverse

When ER is decreased, compliance is increased

Question 14

Passive expiration relies on 2 things:

Answer 14

Elastic recoil and pleural pressure change

Question 15

During passive expiration, what happens to intrapleural pressure and recoil pressure?

Answer 15

Recoil pressure is elevated (+10 for random example), and intraplerual pressure becomes less negative (from -10 to say now -8)

Question 16

Why is there no airway collapse during passive expiration?

Answer 16

Inner (airway) pressure > outer pleural pressure

Question 17

During forced expiration, pleural pressure will be _____ and elastic recoil pressure is +10, which makes the alveolar pressure ___

Answer 17

Very positive (+25), and recoil at first is still +10, so the alveolar pressure is very positive at +35

Question 18

during forceful expiration

Choke point on respiratory tree occurs due to

Answer 18

airway pressure decreases to +20 as it goes up tree, but intrapleural pressure is +25, causing airway collapse before cartilage.

Question 19

The ability for the airway to stay open is SOLELY based on

Answer 19

airway pressure vs intrapleural pressure

(where cartilage isn’t present)

Question 20

In emphysema, recoil pressure may drop to ___

Answer 20

+5 instead of +10

Question 21

Loss of elastic tissue results in loss of recoil pressure AND ___

Answer 21

airway traction

The two combined make small airways much more collapsible

Question 22

More springs means more recoil AND more ____, protecting us from what?

Answer 22

airway traction; airway collapse

Question 23

Example of a fixed obstruction and how it affects flow loops?

Answer 23

ET tube; reduces both inspiratory and expiratory flows, loop is chopped FLAT on top and bottom

Question 24

Why are both flows reduced in fixed obstruction?

Answer 24

Impossible for a ET tube to be as wide as the trachea

Question 25

3 variable intrathoracic examples and what does it affect? Why?

Answer 25

COPD, emphysema, asthma only affects forced expiration Need to use forced expiration causing airway collapse

Question 26

Why does variable intrathoracic obstruction not affect inspiratory pressure?

Answer 26

negative pressure "pulls open" the obstruction, so therefore its not affected.

Question 27

2 variable extrathoracic examples and what does it affect? Why?

Answer 27

Paralyzed vocal works and weak trachea Only affects inspiration Negative pressure during inspiration causes collapse of upper airway because the cartilage is weak and can't keep it open.

Question 28

What can temporarily fix variable extrathoracic pressure?

Answer 28

Mechanical ventilation d/t positive pressure

Question 29

FEV1

Answer 29

Volume of air exhaled in one second of a max forced breath

Question 30

FVC

Answer 30

total volume exhaled with max force (vital capacity)

Question 31

What is a normal ratio of FEV1/FVC?

Answer 31

80% *FEV1 is 80% of FVC, you should be able to exhale 80% of your breath in ONE SECOND*

Question 32

What does a lower FEV1/FVC ratio indicate?

Answer 32

obstructive disease

Question 33

Restrictive disease can be indicated with FEV1/FVC ratios how?

Answer 33

Normal OR high ratio **with** a **LOW** FVC

Question 34

On the FEV1/FVC ratio graph, what does obstructive look like

Answer 34

slow rise, long time to empty lungs, loop is scooped

Question 35

On the FEV1/FVC ratio graph, what does restrictive look like

Answer 35

steep rise but short total volume, loop is narrow and peaked

Question 36

What is a key sign of obstructive disease on flow loops?

Answer 36

Expiratory loop flattens early and drags out

Question 37

Bronchodilator response test results indicate?

Answer 37

IF bronchodilator improves FEV1, its reversible and likely asthma If no improvement, problem is structural and likely emphysema

Question 38

What is the test setup for closing volume and closing capacity test (nitrogen washout test)?

Answer 38

Patient exhales room air to RV, then inhales a full breath from 100% O2 to TLC -all nitrogen in lungs at TLC is from the oxygen remaining at RV, and when patient exhales, nitrogen meter tracks how much you exhale.

Question 39

What do the results of closing volume and closing capacity test (nitrogen washout test) tell us?

Answer 39

Exhaled nitrogen concentration tells you which lung region air is coming from (?if anyone reads this does this sound right? lmk please)

Question 40

At RV, the apex is ____% full, and the base is _____% full

Answer 40

30;20

Question 41

When filling to TLC from RV, the apex adds ___% new air, and the base adds ____% new air

Answer 41

70;80%

Question 42

When inhaling 100% O2, since the base adds more % new air when inhaling from RV to TLC, what does this indicate during exhale?

Answer 42

More dilution of N2 with more air added, and there will be lower concentrations of N2 in air expired from base.

Question 43

Phase I How much nitrogen, how much volume? what respiratory zone did this air come from?

Answer 43

no nitrogen ~100mL 100% O2 came from conducting zones

Question 44

Phase II What happens to nitrogen? what can it estimate and how?

Answer 44

Nitrogen rises Can estimate anatomical deadspace by measuring the midpoint of slope (~150mL in healthy pt)

Question 45

What phase is the transition phase?

Answer 45

Phase II same as fowlers test

Question 46

What phase has the alveolar plateau?

Answer 46

Phase III

Question 47

Phase III Where is the air coming from? What's the slope on graph?

Answer 47

Air from alveoli only Starts with mostly base air (diluted N2), ends with apex air (less diluted N2) Slight upward slope because source shifts from **base to apex**

Question 48

Phase IV What happens to nitrogen? What happens at lung base, and where is the most air coming from?

Answer 48

Sudden steep rise in nitrogen Most air comes from apex with high N2, that's why it rises steeply lung base airways collapse from high intrapleural pressure

Question 49

What could cause phase IV to occur sooner than normal?

Answer 49

Loss of traction, thin or narrow airways

Question 50

Closing volume (Phase IV) is considered to be part of which capacity?

Answer 50

FRC/ERV

Question 51

Start of phase IV =

Answer 51

Closing volume

Question 52

Closing capacity = ___ + ____

Answer 52

Closing volume + RV

Question 53

Why does phase IV matter?

Answer 53

If phase IV starts early, it indicates premature small airway collapse. this is very sensitive to early disease and can detect it before symptoms start.

Question 54

What should be a part of routine physicals?

Answer 54

closing volume

Question 55

What decreases with age in the lungs?

Answer 55

Elastic tissue is lost less recoil -> small airways collapse earlier

Question 56

In a healthy 20 year old, phase IV starts when?

Answer 56

after FRC *hardly any airway collapse during normal breathing, tiny phase IV*

Question 57

In 70 year olds, phase IV starts when?

Answer 57

Before FRC Airway collapse happens on every breath, which means they have to work to get them back open. increased work of breathing even if healthy.

Question 58

When is the cross-over point for when phase IV occurs?

Answer 58

around age 55

Question 59

What lung function has the greatest change as we age?

Answer 59

Closing capacity