Hemodynamics/Oxygenation Flashcards
Delivery of oxygen equation
DO2 = CO x CaO2 x 10
Equation for CaO2
CaO2 = ( Hgb x 1.34 x SaO2) + 0.003 x PaO2
Cardiac output equation
CO = HR x SV
What effects SV? (Stroke Volume)
Preload, contractility, afterload
What is the Fick Formula?
Cellular uptake of O2
CvO2 = [(1.34 x Hgb x SvO2) + (PaO2 x 0.003)]
Reminder CvO2 = content of Venous Oxygen
Hypoxic hypoxia
Deficiency in alveolar O2 exchange
Hypemic Hypoxia
Reduction in the O2 carrying capacity in the blood due to hemorrhage, anemia, and certain drugs.
Stagnant hypoxia
Obstructive shock, reduced cardiac output, or pooling of blood such as heart failure, PE, or shock states
(Train station)
Histotoxic hypoxia
A result of poisoning or metabolic disorders such as cyanide, ETOH, or CO poisoning.
Bohr Effect
States that hemoglobin’s oxygen binding affinity is inversely related both to acidity and to the conc of CO2
Causes of a right shift on the Oxyhemoglobin Dissociation Curve
Raised acid, Raised CO2, Raised temp, Raised 2, 3DPG, Raised PaO2
What is 2, 3 DPG?
Hemoglobin, the protein in the blood that carries oxygen, uses 2,3-DPG to control how much oxygen is released once the blood gets out into the tissues. The more 2,3-DPG in the cell, the more oxygen is delivered to body tissues. Conversely, the less 2,3-DPG in the cell, the less oxygen is delivered.
What is a right shift in the Oxyhemoglobin Dissociation Curve?
Decreased affinity - your “pickier outer” is broken so you tend to pick up duds and your duds are few and far between, but they’re duds so you have no problem “dropping them off”! Right shift is right for the pt.
What is a left shift in the Oxyhemoglobin Dissociation Curve?
Increased affinity - you really like this person you are dating (high affinity) but you’re not secure in your relationship so you are reluctant to let them go. Easy “pick up” but poor “drop off” this is bad!!! High amounts of PRBC!!!
What causes a left shift in the Oxyhemoglobin Dissociation Curve?
Low acid, Low temp, Low 2, 3-DPG, Low PaO2
What waveform is this?
Normal IABP waveform (1:2)
What timing error is this?
Late deflation (most harmful)
End diastolic pressure equal to or higher than unassisted
You wont see a deep V before assisted systolic
Widened slope between end diastolic and assisted systolic
What timing is this?
Late inflation
See the W With augmentation, you can see the diacrotic notch
Balloon inflated long after AV closure
What is this timing?
Early deflation
V rounds out
Assisted systolic equals unassisted systolic
What timing error is this?
Early inflation
Augmentation occurs way above (before) AV closure/diacrotic notch
What timing is this?
Normal inflation and deflation
