Intravenous access and care of the site
At the end of this chapter, the practitioner will be able to:
Identify the different ways of delivering intravenous therapy
Understand what central venous catheters are and their importance in intravenous therapy
Care for a central venous catheter safely and effectively
Understand how to place a peripheral vascular access device
Care for a peripheral vascular access device safely and effectively.
How is intravenous therapy delivered?
Intravenous (IV) therapy can be administered in a variety of ways. The most common is by means of a peripheral venous access device (PVAD), otherwise known as a cannula. A PVAD is a short-term, temporary device that is usually inserted into the veins of the forearm or the hand (Hindley 2004).
If there is difficulty gaining venous access, an alternative is to use a central venous catheter (CVC). CVC is an umbrella term for a line placed into a large vein, known as a central line or central venous line. A CVC can be placed into a large vein leading to the heart, into the neck (internal jugular vein), chest (subclavian vein or axillary vein), or through large veins in the arm. In this case it is also known as a peripherally inserted central catheter (PICC) line.
The femoral vein (in the groin) should be avoided, because there is a higher associated risk of deep vein thrombosis and catheter-related infection compared to the internal jugular or subclavian veins (Loveday et al. 2014). CVCs are typically inserted for longer-term IV access. A CVC is simply a soft hollow plastic tube that can be left in place for any period from a few weeks to a few months (though any such device should always be removed immediately if it is no longer required).
What are CVCs used for?
CVCs are used to administer medication or fluids that cannot be taken by mouth or, in the case of IV therapy, administer fluids or medications that would harm a smaller peripheral vein. CVCs are commonly used for:
Administration of long-term IV antibiotics or parenteral nutrition
IV therapy when peripheral intravenous access is impossible
Administration of medicines that cause phlebitis if given peripherally through a peripheral access device, e.g. amioderone, calcium chloride, potassium and dopamine.
What are the advantages of using CVCs?
Using a CVC has many advantages, as it can also allow for rapid administration of fluid (e.g. for a patient who is in shock). In addition, some CVCs have more than one channel (known as a lumen), which allows for different medications to be administered at the same time, without the medicines mixing together. Some medications (such as adrenaline, dopamine and amioderone) can only be administered centrally, as they cause vasoconstriction in veins.
CVCs generally have the following features:
Soft, hollow tubes that may be separated into two or three different channels (called lumens)
Screw-like adapters on the end of each lumen that allow caps, syringes and intravenous tubing to be connected to them
Hickman lines have plastic clamps on each lumen to close the catheter when it is not in use, or when disconnecting a cap, syringe or intravenous tubing.
CVCs are recommended for short-term use, due to the potential risk of infection (Loveday et al. 2014), and all devices should be removed as soon as they are no longer required.
CVCs can be inserted in the operating theatre, or at the bedside under sterile conditions (depending on the type of catheter used).
A tunnelled catheter is surgically inserted into a vein in the neck or chest and passed under the skin. One end of the catheter remains outside the skin. Medicines can be given through an opening at this end of the catheter. Passing the catheter under the skin helps keep it in place better, lets the patient move around more easily, and makes it less visible.
An alternative to this is an implanted port. An implanted port is similar to a tunnelled catheter, but the device is left entirely under the skin. It is normally placed below the clavicle into the right atrium of the heart, and is used for occasional or intermittent intravenous access. Medication is injected through the skin and into the catheter channel. An implanted port is less obvious than a tunnelled catheter, making it less visible and more acceptable to the patient.
How should healthcare professionals care for CVCs safely and effectively?
Following insertion, the catheter site needs to be regularly checked for signs of bleeding, redness, warmth or discharge. The signs of catheter-related problems and infection are similar for all types of CVCs.
Redness, tenderness, warmth or odour around the catheter site
Temperature of above 38° (or chills)
Swelling of the face, neck, chest or arm on the side where the catheter is inserted
Leakage of blood or fluid at the catheter site or the cap
Inability to flush the catheter, or resistance when flushing the catheter
Displacement (or lengthening) of the catheter.
Your local healthcare provider will have clinical guidelines for CVC care, and it is essential to familiarise yourself with them. These guidelines will vary, depending on where the CVC is being managed – in a hospital setting or in the patient’s home. Many patients at home will be taught to manage the care of their catheter themselves, with support from their local community nursing team.
Remember: you must always wash your hands with liquid soap and water, rinse them well and then dry them thoroughly. You must also wear personal protective equipment before and after touching the CVC (Loveday et al. 2014). To prevent infection, anything that touches the exit site or goes into the CVC must be sterile. An aseptic non-touch technique (ANTT) must be followed at all times when handling the CVC.
ANTT is a technique that was originally developed by Rowley (2001); it maintains asepsis and is non-touch in nature. ANTT is supported by evidence, highlights the key components involved in maintaining asepsis and aims to standardise practice.
The underlying principles of ANTT are:
Always wash hands effectively
Never contaminate key parts
Touch non-key parts with confidence
Take appropriate precautions against infection.
ANTT should be used for both central and peripheral line care, as Rowley (2001) argues that it can be counterproductive to promote two different techniques. The following guidelines are useful in preventing infection:
Only use sterile supplies – discard any products in opened or damaged packaging
Do not touch the end of the CVC when the cap has been removed
If the CVC has a clamp, keep it clamped when not in use
Apply strict ANTT principles as part of your CVC care
Always wear personal protective equipment – sterile gloves and an apron must be worn as a minimum requirement.
The CVC will normally be secured in place with a transparent dressing, unless it is an implanted port in which case a dressing will not be required. A transparent dressing is normally changed every 7 days (or more frequently if it becomes loose, damaged or soiled).
All dressing changes need to be undertaken using a strict aseptic technique to avoid the possibility of infection. Loveday et al. (2014) recommend daily cleansing with 2% chlorhexidine gluconate in 70% isopropyl alcohol in adult patients with a CVC, as a strategy to reduce infection. Iodine in alcohol can be used as an alternative for patients with sensitivity to chlorhexidine (Loveday et al. 2014).
What are the advantages and disadvantages of using PVADs?
Administration of IV therapy using a peripheral venous access device (PVAD) is simpler and cheaper and insertion is less traumatic for the patient, compared to inserting a CVC.
The disadvantages of using a PVAD include the fact that they are only suitable for a shorter period of use, they have a tendency to block more easily, and they have an increased risk of complications. (Complications associated with IV therapy will be discussed further in Chapter 8.)
Site selection for PVADs
The median, cephalic or basilic veins of the lower arm are most commonly used for peripheral access because they are located just beneath the skin (Richardson 2008). The cephalic vein is naturally very large, which makes it an excellent vessel for cannulation. The cephalic vein runs up the lateral side of the arm, from the hand to the forearm, up to the shoulder (humerus). Its position, by the radius in the forearm, also provides a natural splint. The basilic vein is similar to the cephalic vein, in that it is a large vessel which appears prominent, and is lightly supported by the ulna in the forearm. However, the basilic vein can ‘roll’ during insertion of the device, making insertion problematic (McCall & Tankersley 2008).