Fouty-Oxygenation Flashcards
oxygen content of blood (CaO2) units
ml O2/dL blood
oxygen delivery (DO2) units
ml O2/min
oxygen consumption (VO2) units
ml O2/min
higher the altitude, lower the what
pressure (atmospheric)
% of oxygen in atmosphere at sea level
21%
PO2 at sea level
160 mmHg
Pb (atmospheric pressure)
760 mmHg
what stays the same when you are on a plane
nitrogen and oxygen % in the air (the concentration)
what changes when you are on a plane
partial pressure of nitrogen and oxygen (due to atmospheric pressure decreasing)
Patmosphere
PiO2 (air gets humidified in upper trachea)
PAO2 (CO2 here due to alveolar/capillary membrane)
partial pressure of O2 in capillary is _______ to partial pressure of O2 in alveolus
identical
in a normal person, O2 ___ happens rapidly
diffusion and equilibration of PO2 in capillary bed
why is partial pressure of arterial O2 less than capillary and alveolus
b/c venous blood dumps into veins into LA (pulmonary + bronchial) —-mixed oxygenated
PvO2
40 mmHg (tissue extraction of O2 occurred)
oxygen dissolved in blood is solely dependent on _____
PO2
normal CO
5L/min
majority of oxygen for metabolism is carried by _____
Hb
what to think when there is a curve that maxes out at P50 (partial pressure at which Hb is 50% saturated with O2)
CO poisoning
ScO2
98%
SaO2
97%
SvO2
70%
____ binding increases Hb affinity for subsequent O2 molecules
oxygen
range of pressures when saturation and partial pressure of O2 are relatively linear
20-60 mmHg
red curve
green curve
red: advantage of tissue (Bohr effect)
green: advantage of lung (Haldane effect)
exercising causes what
right shift of curve
(increase in CO2 from tissues and decrease in pH and increase in temp.)
fever shifts curve where
right
acidosis shifts curve where
right
hypercarbia shifts curve where
right
has stronger affinity for Hb than O2
CO
decreases Hb saturation of O2 and decreases O2 content
CO
low SaO2 due to what 3 things
decreased PaO2
R shift of curve
abnormal hemoglobin
how many mL in a dL
100 mL
PvO2
PcO2
PaO2
most O2 goes through the blood how
bound to Hb
what mostly determines O2 content
SaO2, NOT PaO2
CaO2 mostly determined by
Hb (g/dL)
oxygen saturation (%)
normal Hb
15
Hb of 20
polycythemia
Hb of 10
anemia
DO2=
CO x CaO2
normal DO2
1000 ml O2/min
2 things that can increase CO to improve DO2
doputamine (ionotrope—increase contractility)
IV fluid
what can you do to increase Hb to improve DO2
transfusion
if SaO2 is lower than you want, what can you do to improve it and improve DO2
give supplemental O2
how can you increase partial pressure of O2
hyperbaric O2
VO2=
CO x (CaO2-CvO2)
normal VO2
250 ml O2/min
consume about _____ of O2 that is being delivered
1/4th
decrease in CO leads to tissue ____
hypoxia
adequate tissue oxygenation dependent on what 2 things
content of O2
flow (of blood)
binds O2 at very low partial pressures in the muscles
myoglobin
____ acts at cytochrome C oxidase to accept electrons
oxygen
low arterial O2
hypoxemic hypoxia
oxygen affinity hypoxia due to what 3 things
CO poisoning
methemoglobin
massive transfusion
low content of O2 due to what
anemic hypoxia
inadequate oxygen delivery due to what
circulatory hypoxia (lactic acidosis)
blocks O2 binding to cytochrome C oxidase causing histologic hypoxia
Cyanide
delivery of O2 is normal but metabolism isn’t (what type of lactic acidosis)
type B lactic acidosis
O2 not getting to tissue for metabolism (type of lactic acidosis)
type A
occurs when O2 not present to accept electrons
lactic acidosis
usual response to inadequate oxygen delivery
lactic acidosis
