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

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 dictated 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

JVP waves
Cont….
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A a positive wave due to atrial contraction.
C a positive deflection due closure of tricuspid
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

Cont…
Kussmaul sign:
A paradoxical rise of JVP on inspiration.
Causes:
Constrictive pericarditis
Cardiac tamponade
Sever Rt ventricular failure

Difference between arterial and venous
pulsation in neck
Change in posture ?
 Change in respiration ?
 Pulsation pattern ?
 Palpation ?
 Occlusion ?

The JVP and carotid pulse can
be differentiated several ways

multiphasic - the JVP "beats" twice (in quick succession) in the cardiac cycle .In other
words, there are two waves in the JVP for each contraction-relaxation cycle by the heart.
The first beat represents that atrial contraction (termed a )and second beat represents
venous filling of the right atrium against a closed tricuspid valve (termed v ). The carotid
artery only has one beat in the cardiac cycle .

non-palpable - the JVP cannot be palpated. If one feels a pulse in the neck, it is generally
the common carotid artery .
occludable - the JVP can be stopped by occluding the internal jugular vein by lightly
pressing against the neck. It will fill from above .

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If a person is standing, his JVP appears to be lower on the neck (or may not be seen at all
because it is below the sternal angle .)The carotid pulse's location does not vary with
standing .

varies with respiration - the JVP usually decreases with deep inspiration. Physiologically,
inspiration decreases the thoracic pressure and increases blood movement into the heart
(venous return), which a healthy heart moves into the pulmonary circulation .
How measure JVP ?
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.

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 verticbal pencil in
cm btw the sternal angle & where it is
crossed by the horizontal pencil.
 Normal JVP up to 3 cm
 JVP + 5 cm = CVP

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.increased
jugular venous
pressure
2.hypotension
3.diminished heart sounds
Thank you