A simple description of a highly technical medical procedure performed routinely in Intensive Care Units and other acute settings.
The use of central venous pressure monitoring in the intensive care and acute care setting is increasing. This is a measure of the venous pressure where the superior and inferior vena cava join prior to entering the right auricle of the heart.
Central Venous Pressure monitoring is more accurate then blood pressure monitoring because changes in circulating volume will be reflected in changes in CVP. The normal CVP is between 5 and 15 CMS of water.
- CVP line
- Sterile gloves and masks
- Local anaesthetic
- Hypodermic needles
- Silk sutures with needle
- CVP insertion kit (with drape, chlorohexidine). .
- Manometer / transducer
- Normal saline or heparinised saline according to Hospital policy
- Electronic manometer or manual Monitoring equipment
- Scissors, sterile dressings
When there is overloading of the circulatory system or there is heart failure the CVP rises. However, when there is dehydration (e.g. diabetes insipidus), fluid loss due to bleeding or shifting of fluids within the body compartments (e.g. shock) then the CVP will fall.
Generally, when the CVP is rising to unhealthy levels the patient may display difficulty with breathing. Conversely, when the CVP is falling there may be a decrease in urinary output and the patient may complain of feeling excessively thirsty. To correct over hydration, as illustrated by a rising CVP the physician may choose to restrict fluids or to administer a diuretic. To deal with a falling CVP the physician might choose to give the patient more fluids or blood as the case may be.
Most institutions have Policies and Procedure manuals which state the indications for the insertion of a CVP monitoring line.
Model with two CVPs
<img alt=”" src=”http://images.stanzapub.com/readers/healthmad/2007/04/03/23758_0.jpg” /
Prior to the insertion of a CVP line an accurate assessment of the patient must me made. A history of the patient may be obtained from the patient, family, notes of previous admissions and the authority who brought the patient to the Hospital.
It is important to explain the procedure to the patient to obtain his or her history. Local anesthetic should be used where the patient does not have an allergy to it. Placing the patient in a supine position is usually sufficient. In some cases where the patient is hypovolumic the trendelenberg position will help dilate the veins in the upper parts of the body and make it easier for the physician to insert the cannula.
Appropriate draping is important to maintain sterility and patient cooperation. In some situations it may be advisable to use a mild sedative to limit pain, awareness of the procedure and keep the patient calm.
After insertion of a CVP line it is usual to have a chest x-ray. This will confirm correct placement of the CVP line.