RATIONALE FOR USE]
Central venous lines have several uses:
-Measurement of central venous pressure (CVP)(indicator of heart’s
1-effectiveness as a pump, circulating blood volume, patient’s vascular
tone, and patient’s response to treatment)
Diagnosis (e.g. evidence of underlying cardiac pathology such as cardiac failure)
3- Drug administration of preparations harmful to smaller lumen peripheral veins (e.g. potassium chloride and dopamine)
4- OR in the absence of suitable peripheral access Fluid administration
(e.g. rapid infusion of a highvolume of fluid in hypovolaemia)
Insertion of a pacing [/move]wire.
CENTRAL VENOUS LINE INSERTION
The aim is to place a catheter into the superior or inferior vena cava,
just above the right atrium. The sites of choice are the:
These allow easiest access and impede patient mobility least. Other potential sites are the:
Median basilica vein.
For these sites, catheters of varying lengths must be used to achieve the final position.
Central venous lines
Patient preparation is vital for what can be a relatively long and
potentially frightening procedure. Explanations and reassurance must be
given to the patient prior to and during the procedure.
These should continue subsequently, during catheter site care,
measurement of CVP and drug or fluid administration. Practical
preparation involves lying the patient flat and raising the foot of the
bed (to promote upper venous engorgement making it easier to puncture
A strict aseptic technique is used for the procedure of insertion. The
catheter is fixed in place with sutures and the entry site covered with
a clear dressing, to allow easy observation without increasing the risk
Infection. The catheter’s position is verified by X-ray – catheters have a radio-opaque strip for this purpose.
3. MEASURING CVP
Several readings are necessary to provide an indication of the patient’s response to treatment.
Measurements can be taken at two points at the sternal angle at the mid axilla point.
The site chosen should be marked on the patient’s skin.
The patient can be positioned in one of two ways, depending which is most comfortable: Lying flat At a 45 degree angle.
Whichever combination is chosen should be recorded so that all subsequent measurements are taken in the same position.
This ensures consistency between measurements.
Measurements are in centimetres of water using a graduated water manometer.
The procedure for measurement is: Zero the manometer (to remove extraneous
pressures and equalise with atmospheric pressure) Fill manometer with
solution (eg. normal saline) using a three-way tap Close off tap from
solution bag Open tap to patient Observe the falling fluid level in the
manometer Record the mean level (the fluid level will ‘swing’ between a
high and a low level and the middle point is usually taken as the
central venous system pressure).
Normal CVP range is: 0-8 cm H2O.
Problems from insertion include:
1- Pnuemo- or haemo pneumothorax caused by puncture of lung (via subclavian or jugular vein)
2- Cardiac tamponade caused by puncture of heart Cardiac dysrhythmia
from over-insertion of catheter tip into right atrium causing
irritation Misplacement (during insertion or subsequent use) causing
problems with fluid infusion or CVP measurement.
Problems occurring during use:
3- Infection Air emboli can develop if any connection is loose Abnormal cardiac rhythms can result from rapid
Infusion of cold fluid
4- Haemorrhage, especially in patients receiving, or
who have received thrombolytic therapy
5. NURSING CARE
Acutely ill patients are more susceptible to infection. Strict aseptic technique is vital to prevent infection during:
Connection of an infusion device
Connection of a syringe for bolus drug dose administration.
Keeping central line handling to a minimum also helps reduce risk.
Nurses should monitor patients, catheters and infusions to ensure
unrestricted flow of fluids. Regular flushing of the line may be
Catheter removal is usually performed by the nurse. Explanation and
reassurance are once again required, and the catheter is removed with
Patient lying flat (if tolerated) and the foot of the bed elevated.
Pressure is applied to the insertion site until bleeding has stopped.
The catheter tip is usually cut off using sterile scissors and sent for microbiological examination.