SV02

Question 1

Components of oxygen delivery

Answer 1

Oxygen content of the blood (Hgb, saturation of Hbg with oxygen and dissolved oxygen) and CO

Question 2

Oxygen content

Answer 2

• Hgb
• Saturation of HGB with oxgyen
• dissolved oxygen (Pa02)

Question 3

Fully saturated oxygen can carry how many mls of oxygen per gram of HGB?

Answer 3

1.38 ml

Question 4

What is the role of HGB

Answer 4

carry oxygen

Question 5

Where is oxygen carried on HGB

Answer 5

4 iron biding sites, not all sites are bound with oxygen

Question 6

oxygen saturation is?

Answer 6

The percentage of hemoglobin saturated with oxygen in the blood

Question 7

Two ways oxygen is carried in the blood

Answer 7

02 combined with hemoglobin (98%)

02 dissolved in plasma = 2%

Question 8

Hemoglobin combines _____ with oxygen to form oxyhemoglobin

Answer 8

reversibly

Hb+ 02 Hb02

Question 9

Arterial blood is mixed with what % of 02

Answer 9

Aorta SV02 = 95-100%

Question 10

Mixed venous blood is what % of 02

Answer 10

Pulmonary artery 60-80%

Question 11

At rest what % of oxygen is used in an average adult

Answer 11

25% with 75% being returned to the lungs

Question 12

Oxygen Partial Pressure (Pa02)

Answer 12

pressure that oxygen exerts in the dissolved state

Question 13

Normal Pa02 values

Answer 13

80-100 mmHg

Question 14

Normal Pv02 values

Answer 14

35-45 mmHg

Question 15

Pa02 affects the ability of O2 to combine with hgb in the lungs and the ability of 02 to be released to the tissues? T or F

Answer 15

True

Question 16

What is arterial blood oxygen content and how is it measured

Answer 16

total amount of oxygen in the blood

measured in ml 02/dl blood

Question 17

equation for arterial blood 02 content

Normal value?

Answer 17

Ca02=(1.38xHgbxSa02)+0.0031xPa02

Normal value = 17-20 ml/dl

Question 18

Components of Ca02

Answer 18

• Hgb
• Sa02
• Pa02

Question 19

What has the greatest effect on arterial blood oxygen content (Ca02)

Answer 19

changes in hemoglobin

Question 20

Define venous blood oxygen content

Answer 20

total amount of oxygen in the venous blood

measured in ml/dl

Question 21

Equation for venous blood oxygen content?

normal values

Answer 21

Cv02=(1.38xHgbxSv02)+0.0031+Pv02

Normal = 12-15 ml/dl

Question 22

Components of Cv02

Answer 22

• Hgb
• Sv02
• Pv02

Question 23

Cardiac output major determinant of ________

Answer 23

02 delivery

C0=SVxHR

Question 24

stroke volume is influenced by what?

Answer 24

• preload
• afterload
• contractility

Question 25

Define Arterial oxygen delivery (D02)

Answer 25

-amount of oxygen delivered to the tissues
measured in: ml 0s/min
-Normal value = 1000 ml/min
-a quarter of what is delivered is used at rest

Question 26

Equation of D02

Answer 26

Da02=

C0xCa02x10=C0xHbgx1.38xSa02x10

Question 27

Units of measure
CO:
Hgb:
1.38:
S02:
10:

Answer 27

CO: L/min
Hgb: gm/dl
1.38: ml/gm
SO2: %
10 - converts liters to deciliters

Question 28

oxgyen consumption (V02)

Answer 28

amount of oxygen consumed by tissues

-measured in ml 02/min

Question 29

Equation for V02

normal value

Answer 29

V02=arterial 02 delivery - venous 02 delivery

normal range = 200-250

Question 30

mixed venous oxygen saturation (Mv02=Sv02)

Answer 30

the percentage of Hgb saturated with oxygen in mixed venous blood

reflects the global balance between oxygen delivery and oxygen consumption

Question 31

Normal range of Sv02

Answer 31

60%-80%

Question 32

A decrease in Sv02 is often the first signal of _______

Answer 32

threat to tissue oxygenation

Question 33

SV02

Answer 33

Decreased oxygen delivery: decrease Hgb, Sa02 and/or CO

Increased oxygen consumption

Question 34

Clinical conditions r/t decreased 02 delivery with poor Hgb concentration, Sv02

Answer 34

• anemia

- hemorrhage

Question 35

Clinical conditions r/t decreased 02 delivery with low Sa02 with Sv02

Answer 35

• hypoxia

- lung dz

Question 36

Clinical conditions r/t decreased 02 delivery with low CO with Sv02

Answer 36

• LV dysfunction
• Shock
• hypovolemia

Question 37

Clinical conditions r/t increased 02 consumption with Sv02

Answer 37

• fever
• seizures
• shivering
• increased work of breathing

increase muscle activity and metabolic rate

Question 38

Increases in Sv02

Answer 38

• mostly commonly due to maldistribution of blood flow d/t sepsis
• wedged PA catheter
• Cyanide poisoning (nitroprusside)

Question 39

How is Sv02 measured?

Answer 39

• reflection spectrophotometry
• from the distal tip of the PAC continuously or intermittently
• Distal tip of the triple lumen catheter
• blood from the pulmonary artery