Test 4 Flashcards
Which of the following is true as oxygen transfer increases?
Arterial PO2 will increase
Which of the following is true as CO2 transfer increases?
Arterial PCO2 decreases
Gas Flow = 2.0 L/min and Blood Flow = 4.0 L/min. What is the gas-to-blood flow ratio?
0.5:1
Gas Flow = 6.0 L/min and Blood Flow = 4.0 L/min. What is the gas-to-blood flow ratio?
1.5:1
changing the GF:BF ratio for a bubble oxygenator
- increase total number of bubbles/ml of blood
- which increases total surface area of the bubbles resulting in increased oxygen transfer
- which increases total volume of bubble resulting in increase carbon dioxide transfer
Membrane oxygenators
- changing pressure gradient only effective for oxygen (increase gradient increases O2 transfer)
- Changing GF:BF changes amount of CO2 being carried (swept) away (increase ratio increases CO2 transfer)
O2 too low
increase FiO2 (fraction of inspired)
O2 too high
decrease FiO2
CO2 too low
decrease GF:BF ratio
CO2 too high
increase GF:BF ratio
SvO2 too low
increase blood flow
Calculating new GF:BF ratio
(Actual PCO2 / Desired PCO2 (which is 40)) x (Ratio that gave you the actual) = New Ratio
PCO2 = 37 mmHg; Ratio = 0.8:1; BF = 5.1 L/min. What is the new gas-to-blood flow ratio?
.74:1
Calculating new gas flow
New Ratio x Blood Flow = New gas flow
PCO2 = 37 mmHg; Ratio = 0.8:1; BF = 5.1
L/min. What is the new gas flow (no units)?
3.8
PCO2 = 60 mmHg; Ratio = 1.1:1; BF = 4.6
L/min. What is the new gas-to-blood flow ratio?
1.65:1
PCO2 = 60 mmHg; Ratio = 1.1:1; BF = 4.6
L/min. What is the new gas flow (no units)?
7.59
what will occur as gas flow is increased into a bubble oxygenator?
bubbles produced/min increases
what will happent to the SA as the number of bubbles produced per minute is increased in a bubble oxygenator?
Gas transfer area is increased
What happens to the volume of gas as the number of bubbles produced per minute is increased in a bubble oxygenator?
Gas volume is increased
as the # of gas bubbles increase in a bubble oxygenator?
O2 & CO2 transfer will increase
as oxygen transfer decreases the arterial O2 does what
Arterial O2 will decrease
as carbon dioxide transfer decreases arterial CO2 does what
Arterial CO2 will increase
as turbulence increases in a membrane oxygenator
A. Oxygen transfer will increase
B. Carbon dioxide transfer will increase
C. Potential for cell damage will increase
What will increase the gas-to-blood flow ratio
- Decrease blood flow; No change in gas flow
- No change in blood flow; Increase gas flow
Gas flow=4 L/min; Blood flow=4 L/min. You increase
your blood flow by 1 L/min and you increase your gas
flow by 500 mls/min. Which of the following best describes the change to the gas-to-blood flow diagram?
GF to BF ratio will decrease
as the Gas-to-Blood Flow Ratio is decreased in a membrane oxygenator
Carbon dioxide transfer decreases
On bypass gas results: PaO2 155 mmHg; PaCO2
55 mmHg; pH 7.25; SvO2 75%. Which value do you look at first?
SvO2
On bypass gas results: PaO2 155 mmHg; PaCO2
55 mmHg; pH 7.25; SvO2 75%. Which value needs to be corrected?
PaCO2
On bypass gas results: PaO2 155 mmHg; PaCO2
55 mmHg; pH 7.25; SvO2 75%. What do you do?
Increase ratio
On bypass gas results: PaO2 155 mmHg; PaCO2 55 mmHg; pH 7.25 mmHg; SvO2 75%. Assuming the old
ratio was .5 to 1, what is your new gas to blood flow ratio? (Rounding x.xx for gas component.)
0.69:1;.69:1
On bypass gas results: PaO2 155 mmHg; PaCO2 55
mmHg; pH 7.25 mmHg; SvO2 75%. Assuming the new
ratio is 0.69:1 and your blood flow is 4.5 liters/minute,
what is your new gas flow? (Rounding x.x) (No Units)
3.1
On bypass gas results: PaO2 250 mmHg; PaCO2 41 mmHg; pH 7.38; SvO2 65%. Which value needs to be corrected?
SvO2
On bypass gas results: PaO2 250 mmHg; PaCO2
41 mmHg; pH 7.38; SvO2 65%. What change do you make?
Increase blood flow
On bypass gas results: PaO2 300 mmHg; PaCO2
41 mmHg; pH 7.38; SvO2 75%. What needs to be corrected?
PaO2
On bypass gas results: PaO2 300 mmHg; PaCO2
41 mmHg; pH 7.38; SvO2 75%.
What change do you make?
Decrease FiO2
On bypass gas results: PaO2 200 mmHg; PaCO2
32 mmHg; pH 7.48; SvO2 72%.
What needs to be corrected?
PaCO2
On bypass gas results: PaO2 200 mmHg; PaCO2
32 mmHg; pH 7.48; SvO2 72%.
What change do you make?
Decrease ratio
On bypass gas results: PaO2 95 mmHg; PaCO2
39 mmHg; pH 7.40; SvO2 75%.
What needs to be corrected?
PaO2
On bypass gas results: PaO2 95 mmHg; PaCO2
39 mmHg; pH 7.40; SvO2 75%.
What change do you make?
Increase FiO2
On bypass gas results: PaO2 250 mmHg; PaCO2
52 mmHg; pH 7.28; SvO2 60%.
Which of the following will you do first?
Increase blood flow
