Pulm 3

Front 1

what does oxygen saturation equal?

Back 1

saO2 = oxygen combined with Hb/ oxygen carrying capacity of Hb (all times 100)

Front 2

what percentage of oxygen is carried dissolved in the plasma?

Back 2

2%

Front 3

waht percentage of o2 is bound to Hb?

Back 3

98%

Front 4

in 100ml of blood, how many grams of Hb are there?

Back 4

15g Hb

Front 5

what is the oxygen carrying capacity of Hb?

Back 5

15g x 1.34 ml O2/g = 20 ml

Front 6

what is the oxygen content of teh blood (value) and what is it measured in terms of?

Back 6

sum of dissolved and bound forms of O2

20 ml O2/100 ml of blood

Front 7

besides expressing oxygen content in terms of ml O2 per 100 ml of blood, what is another way you can express O2 content?

Back 7

%vol

Front 8

waht is teh O2 content of arterial blood? venous blood? (expressed in %vol)

Back 8

arterial blood = 20%vol
venous blood = 15% vol

thus, for each time blood circulates, 5%vol of oxygen is taken up by the tissues

Front 9

what does P50 refer to?

Back 9

the partial pressure of oxygen at which 50% of teh Hb is saturated

Front 10

what is the Hb saturation at PaO2 =
a) 100 mmHg
b) 60 mmHg
c) 27 mmHg

Back 10

1) 99%
2) 90%
3) 50%

Front 11

at what partial pressure of O2 will the Hb O2 sat be 50%

Back 11

27 mmhg

Front 12

across waht partial pressures is the plateau region of the oxgyhemoglobin dissociation curve?

Back 12

b/w 60-100 mmHg

Front 13

waht is something that would shift the oxyHb dissoc curve to the left?

Back 13

CO (interferes with O2 unloading at tissues)

Front 14

what are 4 things that could shift the oxyHb dissoc curve to the right?

Back 14

decreased pH
2,3 BPG (product of anaerobic metab of glu)
PCO2
temp

Front 15

waht does the Bohr shift refer to?

Back 15

the movement of the oxyHb dissoc curve to the right due to increasing PCO2

Front 16

what will anemia do to the oxyHb dissoc curve?

Back 16

nothing - the Hb that is there can be fully saturated

Front 17

what will anemia do to the O2 content vs. PO2 curve?

Back 17

shift it downwards (due to less Hb in the blood, your O2 content will be lower)

Front 18

how will CO affect the O2 content vs. PO2 curve?

Back 18

shift it downwards (greater affinity for Hb than O2)

Front 19

what do you call Hb that has CO bound to it?

Back 19

carboxyhemoglobin

Front 20

the absence of cyanosis indicates normal oxygen transport. T/F?

Back 20

F. Your saturation may be normal, but you may be anemic and still have a low O2 content

Front 21

waht is the CO2 content of arterial blood? venous?

Back 21

arterial: 48%vol
venous: 52%vol

Front 22

what is the three forms CO2 is transported through teh blood?

Back 22

1. dissolved [5%]
2. as bicarb [90%]
3. bound to Hb (carbamino cmpd) [5%]

Front 23

what does the haldane shift refer to?

Back 23

the way in which the state of oxygenation of Hb affects the CO2 dissociation curve. Deoxygenated Hb is better at binding H+ and in turn assisting the blood to load more CO2 to carry away from teh tissues

Front 24

what part of the lungs do interstitial lung diseases affect?

Back 24

the lung parenchyma - distal to the bronchioles. the space in b/w the alveoli and endothelium (usually their BM's are fused - but now they are filled with collagen/inflamm cells/granulomas)

Front 25

tell me the 4 most common forms of interstitial lung disease

Back 25

1. UIP - usual interstitial pneumonia
2. EAA - extrinsic allergic alveolitis
3. sarcoidosis
4. pneumoconioses such as asbestosis

Front 26

what drugs are implicated in causing UIP

Back 26

1. chemotherapy agents
2. amiodarone (anti-arrhythmic)
3. nitrofurantion
4. antidepressants

Front 27

describe how fibroblast foci occur in uip

Back 27

initial epithelial injury --> local fibrin deposition and outgorwht of fibroblasts from the interstitum to organize the fibrin. Due to a lack of plasminogen activating factor, the fibrin is not broken down --> fibroblast foci --> become interstitial fibrous tissue (granulation tissue)

Front 28

why is there loss of alveoli in UIP?

Back 28

the interstitial fibrous tissue accumulates - alveolar collapse

Front 29

5 possible etiologies of UIP

Back 29

-idiopathic (most)
-collagen vascular diseases (SLE, RA, Scleroderma)
-Drug induced (chemotherapeutic agents, amiodarone, nitrofurantion)
-familiarl UIP
-pneumoconioses (asbestosis)

Front 30

will CXR for UIP show nodular/reticulonodular/reticular pattern?

Back 30

reticulonodular pattern

Front 31

where is UIP most manifest (waht part of lung)

Back 31

lower lobes, periphery of lung, periphery of lobules

Front 32

waht are 2 things that could trigger the initial injury in UIP?

Back 32

environmental agesn - eg. cigarette smoke

viral infxn: hep c, EBV

Front 33

how are immunological factors involved in UIP?

Back 33

auto-ABs that react with aveolar epith

Th2 lymphocytes predominate - stimulates fibroblast prolif

Front 34

role of cytokines in UIP

Back 34

increased number of profibrotic cytokines in UIP

Front 35

UIP fibroblast abnormalities

Back 35

abnormalities found in vitro:
-increased motility
-increased rate of proliferation
-achorage indep growth
-resis to apoptosis

Front 36

diff b/w anoxia and asphyxia

Back 36

anoxia - no oxygen
asphyxia - no oxygen and CO2 accumulation

Front 37

does P(A-a)O2 increase/decrease with age? formula?

Back 37

increases with age; A-a gradient =(age/4)+4

Front 38

as you increase FI02, are you going to increase/decrease your A-a gradient?

Back 38

decrease

Front 39

describe the anatomic shunt that occurs in normal healthy individuals and accounts for 1/3 of A-a difference

Back 39

a) part of teh coronary circulation drains into the thebesian veins, and into the LV
b) part of the bronchial ciculation empties into pulm veins returning to the LA

Front 40

what accounts for 2/3 of the A-a gradient?

Back 40

the inherent V/Q mismatch that occurs in our lungs due to gravity and intrapleural P

Front 41

does hypoxemia refer to low partial pressure of oxygen in the blood, or low oxygen content?

Back 41

low partial pressure * THIS IS REALLOY IMPT TO UNDERSTAND (think about anemia, hemoglobinopathies which reduce oxygen content, but don't change PaO2. Also think about CO poisoning...which also decrease the oxygen

Front 42

will anemia cause a decrease in oxygen content, PaO2, or both?

Back 42

oxygen content. The reason why anemia isn't considered to cause hypoxemia is because it doesn't cause a decrease in PaCO2.

Front 43

Could histotoxic poisins such as cyanide be a cause of hypoxemia?

Back 43

NO. While it casues tissue hypoxia, it doesn't change teh PaO2 - thus it does not cause hypoxemia