Lecture 5: Key Things To Remember For Quiz Flashcards
How much oxygen is in plasma?
0.003 ml O2/100 ml plasma…VERY SMALL AMT OF O2 IN PLASMA
Hemoglobin is a ___
Oxygen carrier protein
Each gm of Hb can carry up to ___ ml of O2
1.31 ml of O2 (theoretically up to 1.39 ml/gm)
Hemoglobin combines ___ with O2
Reversibly
What does shift to the right mean?
Hb will release O2 to the tissues (less affinity for O2)
3 causes of shift to the right
- Decreased pH
- Increased DPG
- Increased temperature
What does shift to the left mean?
Hb wants to hold onto oxygen tighter (greater affinity for O2)
3 causes of shift to the left
- Increased pH
- Decreased DPG
- Decreased temperature
At 50% saturation, PaO2 is ___
27 mm Hg
At 75% saturation, PaO2 is ___
40 mm Hg
At 90% saturation, PaO2 is ___
60 mm Hg
Bohr Effect is seen when the curve shifts to the ___
Right
What is oxygen saturation?
The ratio of oxygen bound to Hb compared to the total amount that can be bound
What is oxygen capacity?
Maximal amount of O2 bound to Hb
Very rough rule—PaO2 of 40, 50, 60 for sats _, _, _
70, 80, 90
P50 of Hb = PO2 of ___ mm Hg
27
Shift to the right =
Release of O2, less affinity
Shift to the left =
Hold onto O2, greater affinity
What is CaO2?
Oxygen content in the blood (ml/dL)
How do you calculate CaO2?
CaO2 = (SO2 x Hb x 1.31) + (PO2 x 0.003)
Four types of hypoxia:
- Hypoxic hypoxia
- Stagnant (ischemic) hypoxia
- Anemic hypoxia
- Histotoxic hypoxia
Hypoxic hypoxia =
Low PO2–blood can’t take O2 from the lungs
Stagnant (ischemic) hypoxia =
Low perfusion to an organ—not getting oxygen from blood
Anemic hypoxia =
Low hemoglobin—not enough hemoglobin to carry O2
Histotoxic hypoxia =
Cells can’t use O2 effectively d/t poisoning (i.e.: cyanide poisoning)
