Oxygenation Physiology

Question 1

Hypoxemia

Answer 1

Insufficient oxygenation of the blood which will lead to a hypoxic state

•Hypoxemia always comes first and leads to overall hypoxia

Question 2

Pulmonary Shunt

Answer 2

Alveoli are perfused with blood as normal, but ventilation(supply of O2) fails to supply the perfused region.

Question 3

V/Q mismatch

Answer 3

V-Ventilation
Q-Perfusion/Flow (cardiac output)
-AKA- Venous admixture
*Could be a blood flow problem or poorly ventilated alveoli

Question 4

V/Q mismatch (Ventilation)

Answer 4

•COPD
•Asthma
•Trauma
•Pneumonia
•ARDS

Question 5

V/Q mismatch(Perfusion)

Answer 5

AKA- dead space ventilation
•Cardiogenic shock
•blood loss
•PE

Question 6

Aerobic metabolism

Answer 6

Ability to metabolize(create energy/maintain life) using oxygen. Or an oxygen dependent system.

Question 7

Oxidative Phosphorylation
(Cellular/Aerobic respiration)

Answer 7

You use 36 net ATP

Question 8

Fick formula
(Measuring O2 consumption)

Answer 8

•Cellular uptake of O2
CvO2=[(1.34xHgBxSvO2)] + (PaO2x0.003)]

Hgb concentration has the biggest impact on O2 delivery

Question 9

Anaerobic Metabolism

Answer 9

•Energy production without oxygen
•CO2 production in excess
* Lactic acid build up in the muscles can be a sign of insufficient amount of oxygen to produce energy

Question 10

3 P’s of ETCO2

Answer 10

1- Pulse(do they have one)
2- Perfusion status(MAP<65?)
3- PH(is it low?) CO2 low, HCO3 high?

Question 11

Oxyhemoglobin disassociation curve

Answer 11

*Tip- subtract 30 from SPO2 to get PaO2

Question 12

Bohr Effect

Answer 12

Hemoglobins O2 binding affinity is inversely related to acidity and concentration of CO2
*Oxyhemoglobin curve- Bohr effect= Right shift. better than left shift. “Right for the patient

•Raised acid, Raised CO2, Raised temp, Raised 2-3DPG, and Raised PaO2.
•Respiratory & Metabolic acidosis patients will be a right shift patient.

Question 13

Haldane effect

Answer 13

Increased affinity for Oxygen. Easy to pick up but doesn’t want to let go.
•Low temp, Low acid, Low 2-3DPG, Low PaO2.
•Respiratory and Metabolic alkalosis.

BAD SHIFT they need high amounts of PRBC’s

Question 14

Quiz question:
Oxygen delivery is a product of what?

Answer 14

Answer:
SaO2, Hgb, cardiac output.
SaO2 is a more accurate reading of oxygen in the blood, 98% of oxygen attaches to hemoglobin, and Q moves blood around the body

Question 15

Quiz Question:
Which conditions would cause a left shift of the oxy hemoglobin disassociation curve?

Answer 15

Answer:
Decreased levels of 2, 3 – DPG.
Left shift equals low DPG, temp, CO2 and Pa02.

Question 16

Quiz question:
Multi system trauma patient with massive hemorrhage has mixed disturbance ABG and a BE of -9. What direction will the curve shift?

Answer 16

Answer:
Curve will shift right due to mixed disturbance and BE of -9

Question 17

Quick question:
SPO2 of 87%, what is the approximate PaO2?

Answer 17

Answer:
57 mmHg

Question 18

Quick question:
What causes right shift?

Answer 18

Answer:
Shifts to the right are caused by things being raised. DPG, temp, CO2, PaO2, and acidosis will cause a right shift.