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

Question 1

PH20 at 37degC

Answer 1

47mmHg

Question 2

Dry Gas Pressure, Inspired

Answer 2

PB - PH20 = 760 - 47 = 713 mmHg

Question 3

Minute Ventilation =

Answer 3

VE = Tidal Volume x Respiratory Rate

Question 4

Anatomic Dead Space

Answer 4

Air which remains in the conducting airways at end of inspiration

Question 5

Alveolar Dead Space

Answer 5

Alveoli ventilated but not perfused

Question 6

Physiologic Dead Space

Answer 6

Anatomic + Alveolar Dead Space

Question 7

Minute Ventilation - Physiologic Dead Space =

Answer 7

Alveolar Ventilation

Question 8

Effective/Alveolar Ventilation =

Answer 8

Minute Ventilation (VE) - Physiologic Dead Space

Question 9

Anatomic Dead Space ___ with increasing lung volume

Answer 9

Increases

Question 10

Alveolar Dead Space ___ with exercise

Answer 10

Deacreases

Question 11

In what situation is Increased Alveolar Dead Space not pathologic

Answer 11

Always pathologic

Question 12

Example of Increased Alveolar Dead Space

Answer 12

Pulmonary Embolism

Question 13

Dead space is typically what percent of tidal volume

Answer 13

25-30% of tidal volume

Question 14

How to estimate Dead Space

Answer 14

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

Question 15

Alveolar Gas Equation helps us estimate

Answer 15

PAO2

Question 16

Alveolar Gas Equation helps us determine

Answer 16

Cause of Hypoxemia; Whether due to lung disease or not

Question 17

How is CO2 produced in body eliminated

Answer 17

solely by ventilation

Question 18

Alveolar O2 is a balance of what 2 processes

Answer 18

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

Question 19

Respiratory Exchange Ratio

Answer 19

VCO2/VO2 = 0.8

Question 20

Complete Alveolar Gas Equation

Answer 20

PAO2 = PIO2 - (PaCO2/R)

Question 21

PaCO2 is

Answer 21

40mmHg

Question 22

PIO2 =

Answer 22

(PB - PH20) x FIO2

Question 23

Formula for normal A-a gradient

Answer 23

(Age + 4) / 4

Question 24

5 Causes of Hypoxemia

Answer 24

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

Question 25

__ is a good measure of alveolar ventilation

Answer 25

PaCO2

Question 26

O2 flux = VO2 =

Answer 26

DLO2 (PAO2 - PaO2)

Question 27

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

Answer 27

FALSE

Question 28

T/F: Abnormal Diffusion often causes hypoxemia at rest

Answer 28

False, may contribute to lower PaO2 during exercise

Question 29

Two types of pulmonary shunts

Answer 29

Unventilated alveoli w/ preserved perfusion; A-V malformations

Question 30

Hypoxemia even after 100% O2 =

Answer 30

Shunt

Question 31

Ventilation is __ at the base of the lung

Answer 31

Highest

Question 32

Perfusion is __ at base of the lung

Answer 32

Highest

Question 33

Overall V/Q of WHOLE LUNG

Answer 33

0.8

Question 34

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

Answer 34

TRUE

Question 35

Most extreme low V/Q

Answer 35

Shunt

Question 36

Most extreme high V/Q

Answer 36

Dead Space

Question 37

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

Answer 37

TRUE

Question 38

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

Answer 38

FALSE

Question 39

How is pulmonary edema cleared from alveoli

Answer 39

Sodium channels