ChemAnesthesiaApplications

Question 1

What is CaO2

Answer 1

Unlike either PaO2 or SaO2, the value of CaO2 directly reflects the total number of oxygen molecules in arterial blood, both bound and unbound to hemoglobin.

Question 2

SaO2

Answer 2

Oxygen saturation, which is the percentage of hemoglobin in the blood that is bound to oxygen

Question 3

PaO2

Answer 3

The pressure of dissolved oxygen in the blood.

Question 4

How is CO2 moved throughout the body?

Answer 4

Only a small amount of CO2 is dissolved in the blood. Most is transported in the form of HCO3(bicarb) or bound to hemoglobin.

Question 5

Fick’s Law of Diffusion describes

Answer 5

The transfer rate of gas through a tissue membrane: aka - alveolar surface

Question 6

What factors will directly influence the transfer rate of an inhaled gas

Answer 6

Partial Pressure (driving force)
Diffusion Coefficient (solubility)
Membrane Surface Area

Question 7

What factors are inversely related to transfer rate of an inhaled gas

Answer 7

Membrane Thickness
-Thinner membrane, more transfer
-Thicker Membrane, less transfer

Molecular Weight
-Less weight, easier transfer
-More weight, less transfer

Question 8

What sort of change does anesthetic gas transfer/absorption with a COPD patient have?

Answer 8

COPD patients have reduced alveolar surface area and, therefore, have a slower rate of inhalation induction transfer of anesthetic.

Question 9

How does knowing Oxygen’s solubility coefficient (0.003) help us calculate oxygen delivery?

Answer 9

Multiplying the PaO2 by oxygens solubility coefficient allows us to calculate how much oxygen is dissolved in the blood

Question 10

4 Applications of FICKs Law

Answer 10

1. Diffusion Hypoxia
2. Patient with COPD has slower rate of inhalation induction
3. Calculating Cardiac Output
4. Drug transfer across Placenta