Choosing a vein for venous access
Choosing a suitable site is especially important when treating a child with cancer, and all measures to try and reduce the stress and anxiety related to this event for the child are vital. Dr Wainwright, a paediatric oncologist, explains how this is done as well as highlights the importance of looking after the veins and preserving them for future use.
For both parent and child, choosing a vein for venous access is an important issue. Counselling is a must – explaining to both parent and child what is going to be done, how and why it is going to be done, and in terms that the child can understand. Also explaining to the child that he/she needs to remain still during the procedure so that the first attempt is successful and then it is finished.
Inclusion criteria include healthy-looking skin; an easily accessible area; thin-looking skin; and an area where it won’t bother the child. If the child is left- or right-handed, it is easier if the opposite hand is used in order for them to eat. If the patient is an outpatient, a hand is preferable than using a foot as outpatients prefer to be mobile.
Exclusion criteria include infective lesions in the area; bleeding or bruising close by; marked swelling or oedema near the vein; a tumour lesion nearby; previous thrombophlebitis (inflammation of the wall of a vein with associated thrombosis) close to the area; and painful areas.
EMLA cream – a local anaesthetic ointment – is the child’s friend as it deadens the feel in the area of the skin, where it has been applied, and reduces the anxiety relating to the actual needle prick. It is applied to the skin over the vein and then a bandage is placed over it to retain it in the correct position.
However, before EMLA cream can be applied, selection of the most suitable vein is done. This is where the VeinViewer machine comes to the fore.
The near-infrared light is shined onto various areas, usually starting with the hand or wrist, with a cuff to help the veins to distend and become more prominent. The vein is checked for patency (condition of being open, expanded, or unobstructed), and where the valve is situated.
If the vein has been used before, then the blood flow through the vein is checked by blocking one part of the vein then releasing the pressure and watching the blood flow. The child can also participate and view their own veins and assist in the selection of the best vein.
Once the vein is selected, then EMLA cream is applied. A period of 20 to 30 minutes is allowed for the local anaesthetic ointment to work satisfactorily, prior to attempting the insertion of the line.
Inserting the intravenous (IV) cannulation – which includes the sharp needle and the silicone catheter outside the needle – is the next step to be done. This must be done carefully, and provided the child can manage to keep still can be done uneventfully.
Blood samples can now be taken, if required, and then the needle is removed and the short line is attached and the line is flushed to ensure that all is well. This short line has an anti-reflux valve and a needle-free connection (Neutron), which allows for intermittent venous access without the further use of needles. This reduces the fear a child may have of needles.
What is a short line? It is an extension set +-20cm long that connects to the IV cannula. It separates the IV insertion site from a main IV fluid line. A needle-free connector with a built in anti-reflux valve (Neutron) is bonded to the proximal end of the extension set. This allows for intermittent infusions to be given to the patient and at the same time, reducing the risk of the IV line blocking. The design characteristic of the needle-free connector is of vital importance in reducing the risk of blockage and blood stream infection.
The following step is the application of the strapping to ensure that it is securely fastened. Several plasters are applied and then an Opsite or similar dressing is placed over the entire area.
If the line needs to remain in position for a period of time, a crepe bandage can be gently applied, or sometimes a splint can be used, especially on a toddler or small child who is perhaps very energetic and cannot care for the line unassisted.
Usually a line can last from three to five days, but if it becomes tender or any swelling develops it must be immediately replaced. Some chemo
agents are given over several days, with no problem; while others can damage the vein, and like IV antibiotics can cause thrombophlebitis, with the area becoming painful with a pink discolouration. This must be avoided, if possible.
If the child needs multiple lines over a prolonged period of time, a discussion takes place, between the child, the parents and the doctor, concerning the placement of either a central venous line (CVP), which can remain in position for 10 to 14 days, or the insertion of a permanent line, called a port-a-catheter, which is done under general anaesthesia.
Engaging the patient and parent in understanding the processes that will be followed together with the use of advanced technologies, like VeinViewer and the Neutron short line, make the event less stressful to all parties concerned. These simple but essential methodical steps typically ensure the correct insertion site is chosen and preserved for the relevant therapy which all go a long way to improving the outcomes in treatment being administered.
MEET OUR EXPERT - Dr Rosalind Wainwright
