Non-tunnelled Central venous catheters are often inserted in emergency situations for immediate vascular access. These can be inserted in the subclavian, femoral or jugular veins by experienced personnel. The National Institute of Clinical Excellence (NICE) guidelines advocate that central venous access devices should be inserted using ultra sound imaging to reduce the incidence of complications related to insertion. Most non tunnelled Central Venous Catheters are open ended with no valve within the lumen.
They may have single or multiple lumens. Multiple lumen catheters are advantageous in patients undergoing multiple regular infusions such as patients is high dependency or critical care areas however EPIC 2 guidelines confirm that there is an increased risk of infection related to the number of lumens the catheter has so the benefits need to be weighed against the risks in catheter selection.
CINS workbook draft 9.1 (adult) 38 Advantages of non tunnelled central venous catheters
•
Useful for multiple access•
Familiarity•
Quick insertion•
Central venous pressure monitoring•
Antimicrobial lines available•
Specialised lines e.g for haemofiltrationDisadvantages of non tunnelled CVADs
•
Chest X-ray needed to confirm placement•
High risk of catheter related blood stream Infections (CRBSIs)•
Site specific risk as identified belowFigure 3.2 Diagram of subclavian and jugular venous insertion sites for non tunnelled central venous catheter
CINS workbook draft 9.1 (adult) 39 Table 3.1: Table outlining the problems associated with the 3 veins used in central line placement
Subclavian line placement
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Problem with secretions infecting exit site•
Hair increasing risks of infection•
More skin flora on the chest than arm•
Higher risk of pnemothorax /complications on insertionJugular line Placement
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Increased risk of infection•Increased risk of catheter malposition
•difficult to secure increasing likelihood of mechanical phlebitis
•Restricts neck movement
•Occlusion from „kinking‟.
•Contamination from oral secretions
Femoral line placement
•
High risk of infection from localised flora•
Difficult to access using aseptic technique•
Unable to secure dressings•
Occlusion•
Limited mobility•
Unable to monitor CVP•
Increased risk of deep vein thrombosis compared to jugular or subclavian sitesCINS workbook draft 9.1 (adult) 40 5. Skin tunnelled catheters
Skin tunnelled catheters (including Hickman, Broviac, Groshong and Quinton) commonly are used to provide vascular access to patients requiring prolonged intravenous therapy i.e. months to years. Skin-tunnelled catheters can be either open-ended or closed (with a valve at the end of the line). The catheter is inserted in either the internal jugular vein or the subclavian vein with the tip of the line entering the central venous system at the lower third of the Superior Vena Cava. These catheters have a tunnelled portion exiting the skin and a Dacron cuff inside the tunnel. The cuff inhibits migration of organisms into the catheter tract by stimulating growth of surrounding tissue, thus sealing the catheter tract and providing a natural anchor for the catheter. In general, the rates of infections reported with the use of tunnelled catheters have been significantly lower than those reported with the use of non-tunnelled central venous catheters.
Skin tunnelled catheter placement can be done under general or local anaesthetic, in an X-ray department or theatre. The skin-tunnelled catheter can have more than one lumen and are available in single, double or triple lumen ranges. The number of lumens is dependant upon patient needs. They are excellent for long-term continuous therapy or intermittent therapy and may last for months or years. This can include chemotherapy, long-term antibiotics and TPN.
A skin tunnelled catheter enables blood sampling, avoiding peripheral sampling which is particularly important to patients requiring frequent blood monitoring and preferred by patients who are needle phobic. In order to prevent any risk of infection, the skin-tunnelled catheter requires regular external site care with an appropriate intravenous dressing e.g. mepilex border. Additionally it requires routine flushing with 0.9% Normal Saline followed by 5mls Hepsal (if open ended) at least weekly when not in use.
CINS workbook draft 9.1 (adult) 41 Figure 3.3. Skin tunnelled central venous catheter in relation to underlying vasculature
Skin Tunnelled Catheter advantages
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Skin tunnelled catheters provide a reliable and comfortable venous access.•
Inpatient, outpatient and community use.•
The incidence of central vein thrombosis and catheter embolization is low•
Elimination of pain and discomfort associated with frequent peripheral venepuncture•
Decreased cost of therapy.•
Secured without sutures if cuffedDisadvantages of skin tunnelled catheters
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Anaesthesia and surgical treatment may be required for insertion and removal.•
Need specially trained and skilled professionals for line placement•
Contraindicated if•
anatomical distortions, burns, infection or oedema•
uncorrected coagulopathyCINS workbook draft 9.1 (adult) 42 6. Implantable Ports
Implantable ports have been shown to have the lowest reported rates of catheter-related blood stream infections compared to either tunnelled or non-tunnelled central venous access devices. Most ports tend to be single lumen however dual lumen port are available. An implantable port is placed completely under the skin, usually on the chest or arm. It is used for the administration of medications and fluids via a simple injection through the skin. It can remain in place for months or years.
It consists of two components:
(1) A reservoir encased in silicone. The area of silicone which covers the hollow of the reservoir is termed the septum. The self sealing membrane is pierced in order to administer medications, fluids or feed and to take blood samples.
(2) A silicone catheter, which is introduced into the vein with the tip ending in the superior vena cava.
The implantable port is accessed using special non coring needles which prevent any damage occurring to the port. Under no circumstance should an ordinary needle be used to access a port as it can cause damage.
Advantages
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Only require 1 monthly flushing with 0.9% Normal Saline followed by 5mls Heparin (100units/ml)•
No dressing•
Less risk of infection•
Good for positive body image•
Ability to continue with sports (swimming/bathing)Disadvantages
•
Requires specially trained staff for insertion under anaesthesia•
Specialist equipment – expensive to purchase device and needles•
Still requires a needle which may cause discomfort during access•
Requires surgical removal and can leave a large scarCINS workbook draft 9.1 (adult) 43 General Line Management Issues
All of the careplans for the above lines are found in the CINS guidelines and there are detailed competencies in the appendices of this book to help you with some more specific aspects of IV care. Also in the appendices is one annotated example of the careplan for a peripheral IV cannula which may help to illustrate some of the points below. Some key points have been highlighted here to emphasise management issues to optimise good cannula care.
Infections can be minimized by good cannula care
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Document the site, date and time of cannula placement including reason for siting the cannula and by who on the care plan, reviewing daily the clinical need for intravenous therapy.•
Dressings should be highly permeable and allow visibility at entry site (e.g.mepelex border, IV 3000).•
Change the cannula dressing when not intact or when moisture collects at the site using an aseptic technique•
Dressings should be changed on a weekly basis or when dressing is dirty or loose to prevent extrinsic contamination of the site.•
Securely anchored lines help to prevent phlebitis.•
Assess the cannula using the visual infusion phlebitis (VIP) scale (fig 2.5) for assessment and record the patient‟s score 8hourly.•
Clean the cannula hub with 2% alcoholic chlorhexidine before accessing the system.Preventing cannula thrombosis and maintaining cannula patency will minimize opportunity for infection
•
Peripheral cannula should be flushed with an appropriate volume of normal saline prior to administering IV therapy and immediately after therapy is complete•
Syringe sizes smaller than 10ml may damage the catheter (Hadaway, 1998).CINS workbook draft 9.1 (adult) 44
•
Use a pulsated push/pause action to create turbulence in the lumen and prevent debris build upon internal catheter wall (Todd, 1998)•
Positive pressure within the lumen of the catheter should be maintained to prevent reflux of blood.•
Peripheral cannula should be flushed every 8 hours when not is use.•
There is an increased risk of infection and occlusion when withdrawing blood via a central venous catheter (RCN, 2005).•
There is no requirement to routinely withdraw blood and discard it prior to flushing (except prior to blood sampling) although the first sample can be used for blood cultures (RCN, 2005).•
To ensure that a peripheral IV cannula, close-ended peripheral midline or close-ended PICC is patent before giving any iv medication and kept patent after, just remember SAS:S – Saline flush (push/pause action)
A – Administer IV medication as prescribed S – Saline flush again
•
For tunnelled, non-tunnelled and open ended Peripheral Midline and PICC lines, flush with saline and lock with an appropriate volumes of heparinised saline (10 iu/ml) i.e.equivalent to 50 iu of heparin. If the lumens on a line are being used at least once a day, they do not need to be heparin locked. The heparin dosage for implantable venous access devices (e.g. portacath) is 100iu/ml and dialysis lines may differ. Remember this technique:
S – Saline flush
A – Administer iv medication as prescribed S – Saline flush again
H – Heparin lock