Central Venous Pressure Flashcards
What could happen if the constrict (increase tone) in the peripheral venous compartment?
It is a volume reservoir.
-If you inc. tone, this substantially inc. pressure throughout the system
What happens if you constrict (inc. tone) in arterioles?
They don’t have much volume so it would have very small effect.
What happens if you constrict (inc. tone) in capillaries and arteries?
They essentially do not actively change their volume –> no effect
If you gave a blood transfusion to a patient who recently experienced severe hemorrhage, you would expect:
To expand venous volume –> veins are a volume reservoir with large compliance
What is the central venous compartment?
Volume of blood in the great veins in thorax and right atrium.
In stable conditions what does Venous return =?
VR = CO
What is venous return?
Rate at which blood is COMING BACK to the central venous compartment
What is the significance of central venous pressure (cardiac filling pressure)?
- Pos. influence on stroke volume (cardiac output)
- Negative influence on venous return
- Thus, CVP must always be driven to a value that makes CO = VR
What does decreasing the central venous pressure cause?
Inc. pressure drop across venous system, elevate venous return!!
What does increasing peripheral venous pressure do?
Increases venous return!
In a steady state, venous return will be greater than cardiac output when. . .
NO ANSWER CORRECT!!
VR = CO
Where do the CO and CVP curves intersect?
They intersect when the venous return and cardiac output are the same –> physiological situation
Starlings law:
Heart pumps what it receives!
What is very high central venous pressure a hallmark of?
CHF
What must CHF patients have?
Depressed cardiac output/fxn curve or right shifted venous curve, or both
-Due to excess fluid volume (VR curve), Dysfunctional heart muscle (CO curve)
