ch 8

Question 1

hemoglobin allows whole blood to carry approximately___mL of oxygen per___mL. of blood at the normal arterial PaO2 of 100mmHG

Answer 1

20, 100

Question 2

hemoglobins capacity to carry oxygen is approximately ___ times more than the capacity of plasma alone when PaO2 is___mmHG

Answer 2

67, 100

Question 3

a normal cardiac output of___L/min delivers approxiately ____mL of oxygen to the body tissues each minute

Answer 3

5, 1000

Question 4

is the amount of oxygen delivered enough to meet the tissues resting requirement

Answer 4

yes

Question 5

how many times the body tissues resting requirement is the oxygen delivery

Answer 5

4 times

Question 6

what is the term that describes the unoxygenated hemoglobin

Answer 6

deoxyhemoglobin

Question 7

arterial oxygen saturation (SaO2) is approximately___%

Answer 7

97.5

Question 8

PO2 is ___mmHg at SaO2 of 97.5%

Answer 8

100

Question 9

mixed venous oxygen saturation (SVO2) is normally ____%

Answer 9

75

Question 10

a PVO2 of ___mmHg would have a SVO2 of 75%

Answer 10

40

Question 11

accepted value for hemoglobin oxygen-carrying capacity pre___mL of O2

Answer 11

1.34

Question 12

assuming a concentration of 15 g.dL, what wil be the hemoglobin oxygen-carrying capcity?

Answer 12

20.1mL/dL

Question 13

large PO2 changes cause small to minimal changes in oxygen content, especially at the extreme flat right end of____mmHG

Answer 13

60-100

Question 14

small PO2 changes cause large blood oxygen content changes in the middle, steep portion of the curve of ___mmHg

Answer 14

20-60

Question 15

what levels of PO2 is associated with sharp decreases in oxygen saturation and content

Answer 15

100-60mmHg

Question 16

under resting conditons, what percentage of the arterial oxygen content is extracted by the tissue

Answer 16

25%

Question 17

normally a PO2 of ___mmHg produces as SO2 of 50%

Answer 17

27

Question 18

is the P50 a measure of hemoglobins affinity for oxygen

Answer 18

yes

Question 19

a normal p50 is accurate when the blood temperature is

Answer 19

37C
pH 7.40
PCO2 40mmHg

Question 20

what is the effect of a high p50 on hemoglobins affinity for oxygen

Answer 20

more PO2 is needed for saturation of 50%. Hb more resistance to binding to O2. decreased affinity of O2

Question 21

what conditions decrease hemoglobins affinity for oxygen

Answer 21

*increase temp
*increase CO2
*decrease pH
*blood is acidic
*increase 2,3 DPG

Question 22

what is the name of the phenomenon associated with decreased affinity of Hb for oxygen when PCO2 is high?

Answer 22

bohr effect

Question 23

what is the effect of transfusing banked blood store with a acid-citrate dextrose anticoagulant

Answer 23

*loses 2,3 DPG overtime
*increase Hb affinity for O2
*decrease O2 availability to the tissue

Question 24

what is the normal amount of oxygen extracted by the tissues for each 100mL of blood?

Answer 24

5mL

Question 25

what factors affect oxygen delivery to the tissue

Answer 25

*hemoglobin concentration *arterial hemoglobin saturation w/O2 (PaO2, CaO2) *QT- cardiac output

Question 26

what is the normal amount of oxygen delivered to the tissue

Answer 26

1000ml O2/min

Question 27

what is the normal amount of oxygen consumed by the tissue

Answer 27

250 ml O2/min

Question 28

what is the significance of a decrease in the C(a-V)O2?

Answer 28

CaO2=O2 in arterial blood (going to tissue) CVO2=O2 in venous blood(coming back from tissue) if C(a-V)O2 decreases means tissue is using less O2 from the blood than usual

Question 29

if a pt has arterial blood-gas values while breathing room air: PaO2=100mmHg, SaO2=.975. the hemoglobin concentrate is 7g/dl and the Qt is 8L/dl. will the resting oxygen consumption be affected?

Answer 29

No it will not be affected at all because DO2>VO2(250) *needed to find answer arterial O2 content(CaO2): CaO2=(1.34xHbxSaO2)+(.003xPao2) CaO2=(1.34x7x.975)+(.003x100) CaO2=9.45 O2 del (D02): DO2=QTxCaO2x10 DO2=8x9.45x10=756 D02(756)>VO2 (250)

Question 30

what value is the minimum desaturated hemoglobin concertration in the capillaries when most observers perceive cyanosis

Answer 30

5g/dL

Question 31

explain the presence of peripheral cyanosis

Answer 31

blueness of skin & extremities: fingers, toes, nose or ears due to poor circulation

Question 32

what would be an example of hypoxemia with cyanosis

Answer 32

central cyanosis *due to respiratory failure, heart failure *lungs aren't oxygenating blood

Question 33

what is the rational behind using an FIO2 of 1.0 to manage patients with acute CO poisoning

Answer 33

speed up removal of CO2 from blood restore O2 delivery to body faster -flood lungs w/O2