Download Central Venous Pressure Monitoring Normal CVP is 2

Central Venous Pressure Monitoring
Normal CVP is 2-6 mm Hg.
Central venous pressure is considered a direct measurement of the blood
pressure in the right atrium and vena cava. It is acquired by threading a central
venous catheter (subclavian double lumen central line shown) into any of several
large veins. It is threaded so that the tip of the catheter rests in the lower third of
the superior vena cava. The pressure monitoring assembly is attached to the
distal port of a multilumen central vein catheter.
Assisting with CVP placement
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Adhere to institutional
Policy and Procedure.
Obtain history and assess
the patient.
Explain the procedure to
the patient, include:
o local anesthetic
o trendelenberg
positioning
o draping
o limit movement
o need to maintain
sterile field.
o post procedure chest
X-ray
Obtain a sterile, flushed
and pressurized transducer
assembly
Obtain the catheter size,
style and length ordered.
Obtain supplies:
o Masks
o Sterile gloves
o Line insertion kit
o Heparin flush per
policy
Position patient supine on
bed capable of
trendelenberg position
Prepare for post procedure
chest X-ray
The CVP catheter is an important tool used to assess right ventricular function
and systemic fluid status.
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Normal CVP is 2-6 mm Hg.
CVP is elevated by :
o overhydration which increases venous return
o heart failure or PA stenosis which limit venous outflow and lead to
venous congestion
o positive pressure breathing, straining,
CVP decreases with:
o hypovolemic shock from hemorrhage, fluid shift, dehydration
o negative pressure breathing which occurs when the patient
demonstrates retractions or mechanical negative pressure which is
sometimes used for high spinal cord injuries.
The CVP catheter is also an important treatment tool which allows for:
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Rapid infusion
Infusion of hypertonic solutions and medications that could damage veins
Serial venous blood assessment
Instant Feedback:
The CVP reading helps assess the function of the right ventricle and fluid status.
True
False
There are two ways to read a CVP waveform:
1. Find the mean of the A wave.
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read the high point of the A wave
read the low point of the A wave
add the high point to the low point
divide the sum by 2
the result is the mean CVP
The A wave starts just after the P wave ends and represents the atrial
contraction. The high point of the A wave is the atrial pressure at maximum
contraction. During the A wave the atrial pressure is greater than the ventricular
diastolic pressure. At that point, the atrium is contracted, the tricuspid is open.
Therefore, the high point of the A wave closely parallels the right ventricular end
diastolic pressure. Remember, when the tricuspid valve is open and the right
ventricle is full, the ventricle, atrium and vena cavae are all connected. Therefore,
that point is the CVP.
2. Find the Z-point.
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Find the Z-point which occurs mid to end QRS
Read the Z-point
The Z-point coincides with the middle to end of the QRS wave. It occurs just
before closure of the tricuspid valve. Therefore, it is a good indicator of right
ventricular end diastolic pressure. The Z-point is useful when A waves are not
visible, as in atrial fibrillation. (The c-wave occurs at closure of the tricuspid
valve. The crest of the c-wave is the atrial pressure increase caused by the
tricuspid valve bulging back into the atrium.)
Instant Feedback:
Find the Z-point to read a CVP waveform, when A waves are not visible.
True
False