Oxygen and CO2 Transport Flashcards
O2 Content
Dissolved O2 + 1.34(Hb)(Hb-O2)
Expressed as a volume percent
Henry’s Law
Amount of gas in a fluid depends on partial pressures
- Means that gases move thru fluids by following their pressure gradient
- Once combined w/ a molecule, like Hb, they no longer exhibit a partial pressure
Arterial Blood Saturation
97.4%
Venous blood O2 saturation
75%
Oxygen diffusion constant
.003/PatmO2
Affects of HbCO
- Reduces # of sites available for O2
- Increases the affinity for already bound O2
- less release of O2 at tissues
CO-poisoning
Decreased levels of tissue O2 leading to anemia
Symptoms include: Cherry-red appearance
Dizziness
Confusion
- Lethal amount=0.6mmHg
- Treatment=95%O2/5%CO2
O2 Capacity
Maximal amount of O2 Hb is capable of carrying; DOES NOT include dissolved O2
Hb Saturation
(HbO2/O2 capable of binding) X 100
or
(O2 content- O2 dissolved/ O2 capacity) X 100
Pulse oximeter
Compares photon reflectance of 2 different wavelengths of light to determine Hb/HbO2 ratio
650nm (red)- HbO2 reflects; Hb absorbs
900nm(infrared)- HbO2 absorbs; Hb reflects
*Not affected by concentrations or skin color because a ratio is measured
Pulse oximeter issues
Cannot tell you [Hb] and what Hb is saturated with (could be CO)
Hypercapnia
Increased CO2 leads to respiratory acidosis
-Shortness of breath, confusion, fatigue
Hyperventilation
Can lead to respiratory alkalosis
-Dizziness, light-headedness, numbness of hands/feet
Normal P50
About 26 mmHg
*Increased P50 => Hb-saturation curve shifts to right
DPG in stored blood
Can degrade; leads to increased O2 affinity of Hb