08.13 - Gas Exchange, O2 Transport (Sinclair) - Questions Flashcards Preview

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Flashcards in 08.13 - Gas Exchange, O2 Transport (Sinclair) - Questions Deck (39):
1

PH20 at 37degC

47mmHg

2

Dry Gas Pressure, Inspired

PB - PH20 = 760 - 47 = 713 mmHg

3

Minute Ventilation =

VE = Tidal Volume x Respiratory Rate

4

Anatomic Dead Space

Air which remains in the conducting airways at end of inspiration

5

Alveolar Dead Space

Alveoli ventilated but not perfused

6

Physiologic Dead Space

Anatomic + Alveolar Dead Space

7

Minute Ventilation - Physiologic Dead Space =

Alveolar Ventilation

8

Effective/Alveolar Ventilation =

Minute Ventilation (VE) - Physiologic Dead Space

9

Anatomic Dead Space ___ with increasing lung volume

Increases

10

Alveolar Dead Space ___ with exercise

Deacreases

11

In what situation is Increased Alveolar Dead Space not pathologic

Always pathologic

12

Example of Increased Alveolar Dead Space

Pulmonary Embolism

13

Dead space is typically what percent of tidal volume

25-30% of tidal volume

14

How to estimate Dead Space

1 mL per lean body weight in lbs; 25-30% of tidal volume

15

Alveolar Gas Equation helps us estimate

PAO2

16

Alveolar Gas Equation helps us determine

Cause of Hypoxemia; Whether due to lung disease or not

17

How is CO2 produced in body eliminated

solely by ventilation

18

Alveolar O2 is a balance of what 2 processes

O2 delivery to alveolus by ventilation; O2 removal from alveolus by capillary blood

19

Respiratory Exchange Ratio

VCO2/VO2 = 0.8

20

Complete Alveolar Gas Equation

PAO2 = PIO2 - (PaCO2/R)

21

PaCO2 is

40mmHg

22

PIO2 =

(PB - PH20) x FIO2

23

Formula for normal A-a gradient

(Age + 4) / 4

24

5 Causes of Hypoxemia

Decreased PIO2; Hypoventilation; Diffusion; R-to-L Shunt; V/Q Mismatch

25

__ is a good measure of alveolar ventilation

PaCO2

26

O2 flux = VO2 =

DLO2 (PAO2 - PaO2)

27

T/F: An abnormal Diffusion Capacity Test can separate the mechanisms of diffusion limitation

FALSE

28

T/F: Abnormal Diffusion often causes hypoxemia at rest

False, may contribute to lower PaO2 during exercise

29

Two types of pulmonary shunts

Unventilated alveoli w/ preserved perfusion; A-V malformations

30

Hypoxemia even after 100% O2 =

Shunt

31

Ventilation is __ at the base of the lung

Highest

32

Perfusion is __ at base of the lung

Highest

33

Overall V/Q of WHOLE LUNG

0.8

34

T/F: 100% O2 will correct low V/Q and V/Q mismatch

TRUE

35

Most extreme low V/Q

Shunt

36

Most extreme high V/Q

Dead Space

37

T/F: Most lung diseases cause V/Q mismatch

TRUE

38

T/F: V/Q mismatch is unresponsive to O2 Rx

FALSE

39

How is pulmonary edema cleared from alveoli

Sodium channels