Central Venous Pressure - Nordgren

Question 1

What determines Central Venous Pressure (CVP)?

Answer 1

-CVP always settles at the value that makes CO = venous return. Therefore, anything that shifts the cardiac fun or venous return curve affects venous pressure.

Question 2

True or False: According to Starling’s law, CO always decreases when central venous pressure (Pcv) decreases.

Answer 2

False (only if other influences on the heart are constant its true). In CV system, many things happen simultaneously so CO and CVP may change in opposite directions.

Question 3

In a steady state, venous return will be greater than CO when:

Answer 3

Venous return must always = CO in steady state.

Question 4

In a severely dehydrated person, you might expect to find:

Answer 4

[using venous return and cardiac output curves] Decreased cardiac output. With dec. volume you get dec. CO and CVP.

Question 5

What approaches might a physician pursue in an attempt to lower a person’s cardiac preload?

Answer 5

Cardiac preload = CVP
So physician should lower CVP. This requires a left shift on venous return curve. The two ways that can be done are decreasing circulating volume or decreasing venous tone.

Question 6

If you gave a blood transfusion to a patient who recently experienced a severe hemorrhage, you would expect:

Answer 6

To Expand Venous Volume

Question 7

Which would directly (no compensatory responses) decrease CVP/cardiac filling?

Answer 7

Inc. sympathetic nerve activity to the heart. This shifts the CO curve upward and decrease Central venous pressure.