Post on 09-Jan-2016
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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
Factor affecting CVP
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: Is estimated from Jugular venous pressure
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 atriumThe right internal jugular is the best neck vein to
inspect Provides information about hemodynamic
changes in right atrium & ventricle
Cont.…
The internal jugular vein is lateral to carotid artery & deep to sternomastoid muscle.
External jugular is superficial to sternomastoid
Cont.…
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
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 ?Abdomino-jugular reflux ?Pulsation pattern ?Palpation ?Occlusion ?
Method
Position 45 degreeRest 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 veinConfirm the pulse.
Cont..
Identify the upper limit of venous pulsationJVP is measured by two pencils methodPlace 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
Causes of raised JVP
Right heart failure
Constrictive pericarditis
Superior vena cava obstruction
Pericardial effusion
Cardiac tamponade
Tricuspid valve disease
Cardiac tamponade
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