Transcript Venous Pressure

Venous Pressure
Venous Pressure
Venous Pressure generally refers to the
average pressure within venous
compartment of circulation
 Blood from all the systemic veins flows into
the right atrium of the heart, therefore the
pressure in the Rt atrium called Central
Venous pressure
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Factor affecting CVP
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Cardiac output
Respiratory Activity
Contraction of Skeletal muscles (leg &
abdominal muscles).
Sympathetic Vasoconstrictor tone
Gravity
All these affect CVP by either changing
venous blood volume or venous compliance
How to measure the CVP ??
 Direct:
by catheter introduced into large
thoracic veins
 Indirect:
pressure
Is estimated from Jugular venous
Jugular Venous Pulse (JVP)
There is no valves between the Rt atrium and
the Internal Jugular Vein . So the degree of
distension of this vein is detected by the Rt
atrium pressure.
 Pressure changes transmitted from right atrium
 The right internal jugular is the best neck vein to
inspect
 Provides information about hemodynamic
changes in right atrium & ventricle

Anatomy Of IJV
Cont….
The internal
jugular vein is
lateral to carotid
artery & deep to
sternomastoid
muscle.
 External jugular is
superficial to
sternomastoid
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JVP waves
Cont….
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A a positive wave due to atrial contraction.
C a positive deflection due closure of tricuspid
(carotid pulsation)
X a negative deflection due to atrial relaxation
V a positive deflection due to filling of the right
atrium against the closed tricuspid valve during
ventricular contraction (venous return)
Y a negative deflection due to emptying of the right
atrium upon ventricular relaxation
Abnormalities of wave
Prominent ‘a’ wave :
Right atrial and right ventricular hypertrophy
(due to P.HTN or P.stenosis)
Tricuspid stenosis.
 Cannon wave:
Large ‘a’ wave produce when Rt atrium
contract against closed tricuspid valve. This
seen in complete heart block
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Cont…
Kussmaul sign:
A paradoxical rise of JVP on inspiration.
Causes:
Constrictive pericarditis
Cardiac tamponade
Sever Rt ventricular failure
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Difference between arterial and venous
pulsation in neck
Change in posture ?
 Change in respiration ?
 Abdomino-jugular reflux ?
 Pulsation pattern ?
 Palpation ?
 Occlusion ?
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How measure JVP ?
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LOOK
CONFIRM
MEASURE
Method
Position 45 degree
 Rest the pt head on pillow to ensure neck
muscle relax, and slightly tilted toward the left
side.
 look acorss the neck from the Rt side of the
pt.
 Identify the Jugular vein
 Confirm the pulse.
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Cont..
Identify the upper limit of venous pulsation
 JVP is measured by two pencils method
 Place one pencil at sternal angle vertical to
ground & other pencil at upper limit of
venous pulsation horizontal to the ground
 Measure length of the vertical pencil in cm
btw the sternal angle & where it is crossed
by the horizontal pencil.
 Normal JVP up to 3 cm
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Causes of raised JVP
Right heart failure
Constrictive pericarditis
Superior vena cava obstruction
Pericardial effusion
Cardiac tamponade
Tricuspid valve disease
Cardiac tamponade
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Cardiac tamponade: the accumulation of fluid in the
pericardium in an amount sufficient to cause serious
obstruction to the inflow of blood to ventricle results in
cardiac tamponade.
The three principal features of tamponade are:
1.elevation of intracardiac pressures
2.limitation of ventricular fillng
3.reduction of cardiac output
Beck triad:
1.
2.
3.
increased jugular venous pressure
Hypotension
diminished heart sounds
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