CVP

Question 1

CVP

Answer 1

Simplest measure of cardiac preload

Luminal pressure of intrathoracic pressure of vena cava
o Lower than peripheral venous pressure, not a good indicator of CVP
o Determined by relationship btw central blood vol (venous return, CO), venous tone

Question 2

5-2 Rule of CVP

Answer 2

CVP should only increase 2-5cm H2O with bolus, normalize within 20’
o Larger increases: poor cardiac function, fluid overload
o Increased hydrostatic pressure – venous capacitance reserves near full

Question 3

Correct Placement of CVP in RA

Answer 3

small fluctuations in fluid manometer or displayed on physiograph that are synchronous with heart beat

Question 4

How know if in RV?

Answer 4

-High CVP (alternatively, see high CVP with tricuspid valve insufficiency)
-RV waveforms/large waveforms with each heart beat

Question 5

When measure CVP?

Answer 5

expiratory pause of breathing cycle (PPV, SpV) – changes in pleural pressure affect luminal pressure within CrVC

Question 6

Normal CVP - dogs, cats

Answer 6

0-10cm H2O

Question 7

Normal CV - horses

Answer 7

o Laterally recumbent horses: 15-25, dorsally recumbent/standing 5-10
 Jugular venous pressures may be used as surrogate marker

Question 8

What is CVP a measure of?

Answer 8

PRELOAD PRESSURE

Not true measure of preload volume

Measure of relationship btw blood vol, blood vol capacity – determine endpoint of resuscitation, track acute volume unloading

Question 9

If CVP below range values or decreases with fluid therapy…

Answer 9

absolute or relative hypovolemia, may benefit from fluid bolus

Decreases with fluid therapy, venodilation – needed more fluids

Question 10

If CVP above range values or increases with fluid therapy…

Answer 10

Above range: absolute or relative hypervolemia

Increases with fluid therapy, cardiac intolerance to fluid overload

Question 11

Answer 11

• Fused C, V waves
  -Tricuspid regurg

Question 12

Answer 12

• Atrial fibrillation - lost A wave

Question 13

Answer 13

–Junctional rhythm, AV block
–Functional A wave but not going anywhere bc TV closed - “CANNON” A waves
–Also wee with V tach, 3rd degree AVB

Question 14

Answer 14

–Tricuspid stenosis or reduced RV compliance

Question 15

Answer 15

pericardial constriction

Question 16

Answer 16

Pericardial tamponande

Decreased y descent DT pericardial fluid pressure impairing canal inflow to RA, RV filling

Question 17

A wave

Answer 17

–RA contraction
–Follows P wave on ECG, end diastole

Question 18

Changes to A Wave

Answer 18

-Lost: afib/aflutter
-Increased: tricuspid/PS, PH DT increased resistance to forward flow
-Cannon waves when RA contraction against closed AV valve: junctional rhythm, Vtach AVB

Question 19

C wave

Answer 19

–TV cusps bulging into RA, early systole

Question 20

Changes Assoc with C Wave

Answer 20

–TR causes fusion of c, v waves with blunting of x descent

Question 21

x descent

Answer 21

Mid systole - RA relaxation

Question 22

Changes in X descent

Answer 22

Increased: constrictive pericarditis
Decreased with TR as jet increases RA pressure, suggests RV dysfunction DT decreased apical motion

Question 23

V wave

Answer 23

Late systole, rapid filling of RA
(filling - v shape)

Question 24

V wave changes

Answer 24

Increased in TR from regurgitant jet increase in RAP

Question 25

Y descent changes

Answer 25

Increased in constrictive pericarditis
Decreased in tamponade DT pericardial fluid pressure impairing canal inflow to RA, RV filling

Question 26

Pros - CVP

Answer 26

Information about response to fluid therapy

Question 27

Y descent

Answer 27

Early ventricular filling, early diastole