Common principles of VADs

The VAD should be checked and observed every time the device is being used. If the VAD is not being used for continuous infusions, then the patency of the device should be assessed as frequently as required for the VAD and prior to any medicine administration, transfusions or other infusions.

Frequency of VAD checks by a healthcare practitioner is dependent on clinical area, patient’s clinical condition and types of IV medicines being administered e.g. patients receiving irritant medications may have increased frequency checks and patients in community setting may have a decreased frequency of checks.  Observation should include:

• Insertion point and surrounding areas - are there any signs of inflammation, phlebitis, infection, infiltration or extravasation?
• Dressing – is it clean, dry and intact?
• Integrity of VAD – does the VAD show signs of leakage (fluid or air escaping) or any visible fractures/cracks?
• Security of connections – is the VAD and connections secure? Is there evidence of leakage from connections? If fixation device or sutures used, do these look secure?
• Dislodgment or migration of device – does the VAD look as if it has moved, dislodged or migrated from its previous position?

All checks and actions should be clearly documented.

If the dressing is loose, damp or soiled, it should be replaced immediately, and the patency of the VAD should be assessed. 

All VADs should be removed when no longer clinically indicated.  VADs may remain in situ for as long as required unless there is a clinical for removal and there are no signs of phlebitis or infection.

Maximum dwell times should be in line with manufacturer’s recommendations.

Medical and nursing staff should review the need for intravenous therapy, including antibiotics, on a daily basis and consider IV to oral switch over, if appropriate.

The purpose of a NFAD is to facilitate accessing a VAD during the administration of single or multiple IV infusions, reduce the risk of catheter related blood stream infections (CRBSI) and needle stick injuries. NFADs should be attached to VADs, unless these connectors are inappropriate for use with a particular VAD.

All needle free access devices, whether single or multiple, with or without extension sets, must be primed before use with sterile IV 0.9% sodium chloride solution.  

There are a huge variety of different NFADs available and clinical specialities/practitioners should determine the NFAD appropriate to the patient’s need and VAD requirements. Anti-reflux valve NFADs are also available and should be considered for use when high risk for extravasation medications and therapies are being administered.

NFADs should be changed according to manufacturer’s advice unless there is a clinical rationale to increase the frequency.

*Some clinical areas may have a rationale to change NFAD more frequently than manufacturer’s recommendations e.g. every 72 hours.

A PVC must always have a NFAD with extension set attached to avoid inadvertent mechanical phlebitis when attaching and disconnecting to the NFAD (*with an exception in theatres, endoscopy and imaging). 

Evidence-based research recommends that using a turbulent push-pause flush with sterile 0.9% sodium chloride (NaCl) in a 10ml syringe (or larger) finishing with positive pressure is sufficient to maintain catheter patency and ‘lock’ VADs.

Blood discards are small volumes of blood withdrawn to ensure patency and placement of the tip of the VAD. This small sample is frequently referred to as a ‘blood discard’ as it is not used for therapeutic monitoring purposes, except for blood cultures. Discard volumes should be dependent on required investigations and should be discussed with medical staff. Small blood volume losses from repeated blood discards can have an accumulative effect and can become particularly significant in infants and small children where total blood volume is much less overall.  In this situation, consideration should be given to the volume discarded and the overall impact this may have and whether the blood needs to be discarded or returned.

If a catheter locking solution is used, at least 2mls discard should be taken every time the line is accessed to ensure the solution is removed.

Within NHSA&A, blood samples are routinely obtained using venepuncture equipment and a peripheral blood sample. In certain circumstances, some VADs may be used to obtain blood samples. The decision-making process is complex and multifactorial. 

When considering using a VAD to obtain blood samples, it is crucial to consider the potential increased risk of infection when accessing the VAD over increased skin punctures from multiple venepuncture attempts. Some VADs are inserted with particular purpose in mind. For example, patients undergoing long term chemotherapy treatment with difficult intravenous access may have a CVAD inserted to avoid multiple cannulations and venepunctures - it may be appropriate to sample from the VAD. Blood sampling from VADs must only be undertaken by registered healthcare practitioners, competent to do so.

Patient’s allergies must be checked prior to any procedure from a dressing, topical solutions and medicines perspective. If the patient has a chlorhexidine allergy, alcoholic povidone-iodine solution can be used instead of 2% chlorhexidine in 70% isopropyl alcohol.