Resp - Pulmonary Q/V Flashcards Preview

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Flashcards in Resp - Pulmonary Q/V Deck (28):
1

normal V/Q

4/5 = 0.8

2

normal V/Q with abnormal V and Q

lobar pneumonia
V in lobe decreased
hypoxia --> vasoconstriction
Q decreased

3

ventilation and lung regions

highest in base (Pa>Pv>PA)
lowest in apex (PA > Pa)

4

flow and lung regions

highest @ base
lowest @ apex

5

V/Q in lung regions

high in apex (>1)
low in base (<1)

6

Pip in lung regions

more negative @ apex (distend alveoli)
less negative @ base (don't distend as much)

7

normal P(A-a) O2

< 20 mm Hg
age/4 + 4
(increase w/ age)

8

causes of hypoxemia

hypoventilation
low inspired O2
R/L shunt
V/Q mismatch
diffusion impairment
(first 2 have normal P(A-a)O2

9

hypoxemia

PaO2 < 80

10

hypoventilation causes

depressed respiration (morphine, sedatives)
neuromuscular diseases

11

hypoventilation Ps

PAO2 down (RR down)
P(A-a)O2 normal (PAO2 and PaO2 lower qually - no lung problem)

12

hypoventilation Tx

supplemental O2

13

low inspired O2 causes

Patm down (altitude)
FIO2 down (improper anesthesia)

14

low inspired O2 Ps

PAO2 down (PIO2 down)
P(A-a)O2 normal (O2 equilibrium normal)

15

low inspired O2 Tx

supplemental O2

16

R/L shunt causes

congenital defect
foramen ovale open
alveolar filling/atelectasis

17

R/L shunt Ps

P(A-a)O2 up (A same, a down)
PaO2 down (added deoxygenated blood)
PaCO2 normal or up

18

R/L shunt Tx

NOT O2

19

V/Q mismatch causes

pneumonia
pulmonary embolism
COPD

20

V/Q mismatch

usually Q normal
P(A-a)O2 increased

21

V/Q mismatch Tx

supplemental O2

22

physiologic response to low V/Q

PaO2 down --> regional pulm vasoconstriction
put blood in good spots
Q goes down to match V

23

physiologic response to high V/Q

PaCO2 down --> regional bronchconstriction
put air in good spots
V goes down to match Q

24

low V/Q and PaO2/CO2

low V/Q - high ventilation or low perfusion --> low PaO2, high PaCO2

25

high V/Q and PaO2/CO2

high V/Q - low ventilation or high persusion --> high PaO2, low PaCO2

26

diffusion impairment cause

interstitial lung disease (scarring
pulmonary fibrosis
** during exercise

27

diffusion impairment Ps

P(A-a)O2 normal @ rest
P(A-a)O2 increased during exercise
PaCO2 is normal

28

diffusion impairment mech

collagen deposition in interstitium prevents O2 diffusion
exercise --> RBCs going by faster than can pick up O2