As well as being highly prevalent in critical care environments, central venous catheters also pose a number of serious risks to patients and require thorough care and assessment by healthcare workers.
A central venous catheter (CVC), also known as a central line or central venous access device, is a thin, flexible tube used to deliver treatment or draw fluids (ATS 2019).
How does a CVC Work?
A CVC is inserted through the patient’s skin and into their body through a peripheral vein or proximal central vein - generally either the internal jugular (neck), femoral vein (groin) or subclavian vein (upper chest). The tip of the CVC should lie on the right side of the heart within either the superior vena cava, the right atrium, or the inferior vena cava (Smith & Nolan 2013).
Many CVCs are ‘multi-lumen catheters’, meaning the catheter has multiple (generally two or three) internal channels that can deliver several medications to the patient simultaneously (usually dispensing each fluid at a slightly different point along the catheter) (LHSC 2014).
(Note: Always check whether medications are compatible before ‘piggybacking’ them in the same lumen.)
A peripherally inserted central line (PICC line) is a type of long CVC that is inserted into one of the large veins above the bend of the patient’s elbow, with the tip resting in the same place as a regular CVC (Macmillan Cancer Support 2015).
CVC insertion is a common procedure, with approximately 15,000 devices inserted every year in New South Wales ICU wards. However, it poses a variety of significant risks, with catheter-related complications occurring approximately 15% of the time overall (ACI 2014; Smith & Nolan 2013).
For this reason, it is important to have a thorough understanding of how to care for a patient with a CVC.
What is a CVC Used for?
In comparison to an intravenous catheter (IV), a CVC is longer, larger and able to stay in situ long-term due to the greater tolerance of large veins. As a result, a CVC provides convenience to not only the clinician treating the patient, but also to the patient, avoiding trauma from repeated needle and catheter insertion (ATS 2019; ACS 2016).
Reasons for using a CVC may include:
Delivering several medications to a patient simultaneously;
Delivering medication to the patient over a long period of time (e.g. chemotherapy, antibiotics);
Delivering medication to an outpatient while they are at home (a CVC is less likely to come out of the vein);
Delivering large amounts of fluid or blood to a patient;
Directly measuring central venous pressure in a large or central vein;
Drawing several blood samples within one day (so that the patient does not need to endure needles every time);
Delivering nutrition directly into the blood; and
Delivering vesicants - drugs that may seriously damage skin and muscle tissue if they leak outside the vein.
(ATS 2019; ACS 2016)
Caring for a Patient with a CVC
When caring for a patient with a CVC, you need to ensure the safety and security of the catheter, have an understanding of which medications are compatible when performing safety checks and be able to identify any infections of the insertion site.
How to perform a CVC assessment:
Perform hand hygiene; don gloves and personal protective equipment.
Perform the bed area safety check. CVC assessment is also part of this process.
Perform a head-to-toe assessment.
Identify the CVC and inspect the insertion site. Look for any signs of infection (e.g. redness, swelling or pain).
Ensure an occlusive dressing is intact to reduce risk of infection. If not, you may need to consider changing the dressing (follow hospital protocol when performing a dressing change).
Identify how many lumens are present.
Ensure all intravenous lines are securely connected to the lumens.
Measure the length of the line from the skin to the first hub - this clarifies how far the line is in the vein and indicates any potential displacement. Refer to hospital protocol if this is the case.
Traceback each line to the infusion pump to ensure each medicine is connected to the right line.
Ensure lines are labelled clearly at the site of the lumens, and the fluid bags containing the medications are also labelled correctly. Identify when each line was last changed and label it accordingly. Follow hospital protocol.
Ensure multiple medications running on the same lumen are all compatible. Refer to appropriate medication text, as per hospital protocol.
Aspirate and flush any lumen that is free from any lines to ensure patency.
(Tsotsolis et al. 2015; Smith & Nolan 2013; Queensland DoH 2015; ACI 2013)
Central Venous Catheter Complications
CVC insertion is prone to a variety of complications including insertion issues, incorrect placement, internal injury and infections (Patel et al. 2019).
The experience level of the physician responsible for inserting the CVC is shown to be a crucial factor in the occurrence of complications; insertion by an individual who has performed over 50 catheterisations is half as likely to result in a mechanical complication as one performed by a less-experienced counterpart. Furthermore, unsuccessful catheterisation attempts preceding the insertion will also increase the likelihood of complications (Tsotsolis 2015).
Possible complications include, but are not limited to:
Infections, as catheters inserted into the body make it easier for bacteria from the skin to enter the bloodstream;
Blood clots forming in the catheter;
Pneumothorax (collapsed lung) caused by the needle accidentally piercing the lung during insertion;
Air embolism caused by air entering the bloodstream through the catheter. This occurs rarely but is a serious medical emergency.
Damage to the blood vessel;
Side effects caused by the incompatibility of medicines that are being administered together on one lumen;
Catheter fluid leak; and
Migration of the catheter, halting the administration of medication.
The risk of complications, some potentially serious, means CVC safety checks are imperative. You must always ensure medication safety and compatibility is maintained, and the line is secure and safe from harm.