Arterial Blood Gases–O2 Carriage/CO2 Carriage Flashcards
There is about 26.4 mM of carbon dioxide in the blood. Of that, roughly ____ is in the form of HCO3-; the rest is split evenly as CO2 and carbamino proteins.
24 mM
Describe the Bohr effect.
CO2 binding to hemoglobin decreases the oxygen affinity of hemoglobin
What is the Haldane effect?
Oxygen binding decreases the CO2 affinity of hemoglobin
What factors decrease the oxygen affinity of hemoglobin?
Increased temperature, decreased pH, and increased CO2 concentration
What is D(O2)?
The delivery of oxygen to a tissue in one minute. It is given by the following formula: flow x C(a[O2]).
C(a[O2]) = _____________.
SaO2 x [Hb] x 1.39 ml O2/gm Hb + 0.003 x Pa(O2)
Define hypoxia.
Low O2 at tissues (P[O2]
What pathophysiologies can lead to hypoxia?
Low cardiac output; low arterial oxygen saturation (a syndrome called hypoxemia); or failure to deliver oxygen to the tissues (such as from anemia or carbon monoxide poisoning)
What five things can cause hypoxemia?
Decreased P(I[O2]); decreased P(A[O2]); diffusion problems; shunts; and V/Q mismatches
At high altitude, arterial CO2 _______, due to _________.
decreases; increased respiratory rate
What is the conversion between mM of CO2 and Torr?
0.03 mM/Torr
How does V(O2) differ from D(O2)?
D(O2) represents the amount of oxygen delivered to the tissues in one minute, while V(O2) represents the amount of oxygen consumed in one minute.
V(O2), which is the amount of blood consumed by the tissues in one minute, is given by ___________.
Q x ∆C(O2)
Also written Q x (Ca[O2] - Cv[O2])
Hypoxemia is defined as _______ in Denver and ________ at sea level.
Pa(O2)
What are some ramifications of carbon monoxide poisoning?
CO (1) decreases the Sa(O2); (2) increases O2 affinity, which decreases O2-offloading; and (3) binds tightly and won’t release