Lectures 16 & 17: Capnography, Equilibration, Hgb (Exam III) Flashcards
What is the solubility coefficient of O₂?
Give answer per dL of solution
0.003 mLO₂/ mmHg PO₂ / dL of blood
Calculate how much O₂ is dissolved per deciliter of arterial blood.
0.3 mL O₂ / dL of blood
Calculate how much O₂ is dissolved per deciliter of venous blood.
(0.003 mL O₂ ÷ 100mL blood x PO₂) x 40 mmHg =
0.12 mL O₂ / dL of blood
How much O₂ is dropped off at the tissues per deciliter every minute?
Δ = 5mLO₂ /dL blood
Given a partial pressure of 100mmHg, we should be able to dissolve a max of ____ mL of O₂ in a dL of blood
0.3
How many O₂ does one Hb molecule carry?
4 O₂ molecules.
I assume this means 8 total oxygen atoms?
How many mL of O₂ can Hb (hemoglobin) carry?
1.34 mL O₂ /gram Hb
How many grams/dL of Hb do we have?
15 g/dL
Differentiate Deoxyhemoglobin and Oxyhemoglobin.
- Deoxyhemoglobin = Hb + O₂
- Oxyhemoglobin = HbO₂
What factors/conditions would accelerate the formation of deoxyhemoglobin?
- ↓ pH
- ↑ H⁺
- ↑ CO₂
- ↑ Temp
What factors/conditions would accelerate the formation of oxyhemoglobin?
- ↑ pH
- ↓ H⁺
- ↓ CO₂
- ↓ Temp
What is the formula for determining max carrying capacity?
What would be the carrying capacity of someone who had a hemoglobin of 10 g/dL and Hb carrying capacity of 1.2 mLO₂ /gHb ?
12 mLO₂ / dL of blood
Will decreased Hb (hemoglobin) result in an increase or decrease to cardiac workload?
↑Hb = ↑ cardiac workload
More Hb = increased viscosity = harder for the heart to pump.
At what partial pressure should our Hb molecules be completely saturated?
100 mmHg O₂
According to graph below, for normal blood, when would one see a carrying capacity of 15mLo2/dL ?
PO₂ = 40mmHg = 15 mLO₂/dL
What effect(s) does CO have on Hb molecules?
- CO becomes bound and “sticks” (has a high affinity and won’t unbind from Hb molecule).
- CO makes O₂ molecules have a higher affinity so they won’t be unbound as easily as normal.
Based on the graph below, when would we expect an SaO₂ of 75% ?
At 15 mLO₂/dL (100% of SaO₂ occurs at 20 mLO₂/dL)
What is normal SaO₂ at a PO₂ of 100mmHg?
Why?
SaO₂ = 97.4%
Lower than 100% due to presence of methemoglobin and venous bronchiolar drainage into arterial supply.
What occurs with Hb as as PO₂ decreases?
Decreasing PO₂ allow for easier unloading of O₂ from Hb due to decreased affinity.
What is CaO₂ ?
Content of oxygen in the arterial system in mL.
Hb-bound O₂ and PaO₂
What is CvO₂ ?
Content of oxygen in the venous system in mL.
Hb-bound O₂ and PvO₂
What is the CaO₂ assuming an SaO₂ of 97.4%, and PO₂ of 100mmHg?
19.88mL O₂ /dL blood
(dissolved: 0.3 mLO₂) + (Hb-bound 19.58 mLO₂)
What is the CvO₂ assuming an SvO₂ of 75%, and PvO₂ of 40mmHg?
15.195 mLCO₂ / dL blood
Dissolved: 0.12 mLCO₂
Bound: 15.075 mLCO₂
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How does the affinity of HbF (fetal hemoglobin) compare to that of HbA (adult hemoglobin) ?
HbF exhibits much greater affinity for O₂ than HbA
Why does HbF have a greater affinity for O₂ than HbA?
Mechanism to ensure adequate oxygen delivery to the baby.
PaO₂ can vary from ___ to ___ without much change in Hb saturation.
70 to 100
What is 2,3 DPG?
What are the various names for it?
Also known as 2,3 BPG
Product of metabolism (produced by RBC during glycolysis)
- 2,3 Biphosphoglycerate
- 2,3 Diphosphoglycerate
- Biphosphoglyceric acid
What cells produce a lot of 2,3 DPG?
RBCs
Blood products will have ________ 2,3 DPG levels from storage.
decreased
What factors/conditions will cause a rightward shift in the oxyhemoglobin dissociation curve?
- ↓ pH
- ↑ H⁺
- ↑ CO₂
- ↑ 2,3 DPG
- ↑ Temp
The Bohr effect is related to what concept?
Oxyhemoglobin dissociation curve (O₂ affinity)
What molecule besides Hb has reversible O₂ carrying capabilities?
Myoglobin
Where is myoglobin found?
skeletal muscles
particularly ones that see a lot of use like the calf muscles
What element is pertinent in myoglobin and hemoglobin capabilities to carry O₂ ?
Fe⁺⁺
What sort of affinity for O₂ would myoglobin exhibit compared to Hb?
Myoglobin = ↑O₂ affinity
What things will decrease measured SvO₂ ?
- ↑O₂ consumption
- Diet pills
- ↓O₂ delivery (↓CO)
What things will increase measured SvO₂ ?
- Poor O₂ extraction
- ↓ metabolic activity
If someone is young and healthy, SvO₂ should be ___% or greater.
70
What does P50 mean?
PO₂ that correlates with 50% O₂ saturation.
What concept does the graph below convey?
Differing affinities for O₂ between venous and arterial blood based on the P50 metric.
Which of the lines on the graph below are venous and arterial?
What is the P50 of arterial blood?
Pa50 = 26.5mmHg
What is the P50 of venous blood?
Pa50 = 32mmHg