Exam #6: Lung Volumes Flashcards Preview

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Flashcards in Exam #6: Lung Volumes Deck (33)
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1
Q

How are lung volumes measured?

A

Spirometry

2
Q

What is tidal volume?

A

Volume normally breathed in & out

3
Q

What is inspiratory reserve volume?

A

Volume inspired with maximal inspiration - tidal volume

4
Q

What is expiratory reserve volume?

A

Volume of expired air past tidal volume

5
Q

What is the inspiratory capacity?

A

“Everything that can be breathed in”

Tidal volume + inspiratory reserve

6
Q

What is the vital capacity?

A

“Everything that can be breathed in & out”

7
Q

What is the residual volume?

A

Volume of air left in the lungs after maximal expiration

8
Q

What is the importance of residual volume?

A

Prevention of alveolar collapse

9
Q

What is the total lung capacity?

A

Total volume of air in lung

10
Q

Can residual volume or functional residual capacity be measured with spirometry?

A

NO

11
Q

What is a restrictive lung pathology? How does this pathology change lung volumes? Provide examples of this pathology.

A

Condition that restricts expansion of lung

–>Volumes are smaller compared to normal population

E.g.

  • Pleural effusion
  • Increased elasticity
  • Inflammation
12
Q

What is an obstructive lung pathology? How does this pathology change lung volumes? Provide examples of this pathology.

A

More air in than out & dramatic increase in residual volume

–> “air trapping”

E.g.

  • COPD
  • Asthma
13
Q

What is FVC?

A

Forced vital capacity= total amount of air that can be forcibly expired after maximal inspiration

14
Q

What is FEV1?

A

The volume of air that can be forcibly expired in the first second

*Speed

15
Q

Why is the FEV1/FVC ratio important?

A

It is a reflection of RESISTANCE to airflow

  • Big ratio= small resistance
  • Small ratio= big resistance (obstructive)

.75- 0.8= normal

16
Q

Draw the flow volume curve. Label the large & small airways.

A
X= Volume (L)
Y= Flow (L/s)
17
Q

What is PIF?

A

Peak inspiratory flow

18
Q

What is PEF?

A

Peak expiratory flow

19
Q

What is FEF?

A

Forced expiratory flow

20
Q

What is FEF 25, 50, & 75?

A

Forced expiratory flow rate at varying volumes of air out

21
Q

Draw the change seen with obstructive lung disease on volume & flow curve. How can this be used clinically?

A

Measure the efficacy of bronchodilators

22
Q

Draw the flow-volume curve in upper airway FB obstruction.

A

N/A

23
Q

Draw the flow-volume curve in restrictive lung disease.

A

N/A

24
Q

How does the FEV1/FVC ratio change in obstructive lung disease? Why?

A

Less than 0.7

  • FCV & FEV1 decreased, but FEV1 is decreased more than FVC
25
Q

How does the FEV1/FVC ratio change in restrictive lung disease? Why?

A

Greater than 0.8

FVC & FEV1 are decreased, but FEV1 is decreased less than FVC

26
Q

What is physiologic dead space?

A

Volume of the lung that does NOT participate in gas exchange–the volume of the conducting airways

Note that this is decreased with intubation

27
Q

How is physiologic dead space clinically related to mechanical ventilation?

A

Must be substracted

28
Q

What is the functional dead space?

A

Alveoli that do NOT participate in gas exchange i.e. ventilated but not perfused

*This is 0 normally

29
Q

What is minute ventilation?

A

Total rate of air movement into and out of the lungs in one minute

Tidal volume x RR

30
Q

What is the alveolar ventilation?

A

Rate at which new air reaches the gas-exchange areas of the lungs (minute ventilation minus dead space)

RR x VT- VD

31
Q

Write the alveolar ventilation equation. What is the essential premise of this equation?

A

Alveolar ventilation must match metabolism

32
Q

Work through examples on slide #38.

A

N/A

33
Q

What cannot be measured with a spirometer?

A

RV
FRC
TLC

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