In today’s VETgirl online veterinary continuing education blog, Amy Newfield, CVT, VTS (ECC) reviews what a central line is, what complications can be seen from them, and what types of central lines are readily available in veterinary medicine.
What is a Central Line?
Central venous catheter placement is done by passing a long catheter into a large vein such as the jugular or caudal vena cava. Placement of such a catheter is usually performed for a variety of reasons such as long term administration of IV fluids and medications, use of hyperosmolar solutions (greater than 600mOsm/L), parenteral nutrition, potentially irritating drugs known to cause phlebitis and tissue sloughing (e.g., diazepam, pentobarbital, mannitol, vasopressor CRI), blood sample collection and central venous pressure (CVP) measurement. An additional advantage to central catheter placement is that the catheter is secured directly to the skin and is less likely to be affected by patient movement. Due to their length they are also less likely to cause infections or phlebitis.
Central venous catheters are not benign, and it is important that the benefit to placing outweighs the risks. They can cause complications in animals with coagulation abnormalities (e.g., both hyper- and hypocoagulability), or in patients at risk of thrombus, such as those with immune mediated hemolytic anemia, hyperadrenocorticism or pancreatitis. These catheters should also not be chosen for rapid fluid administration and the patient should have a peripheral IV catheter placed first for fluid resuscitation and stabilization before placing a central line.
Types of Central Lines
Through-the-needle (e.g., Venocatheter, Intracath) are one of the easiest types of central lines to place. They are generally packaged in a sterile plastic covering. While the entire catheter is enclosed, it is still advised to wear sterile gloves to keep the area as clean as possible. The needle is inserted into the vessel and the catheter is then pushed through the needle. Because of this, it is impossible to remove the needle completely so a needle guard is placed around the needle and it then must be secured and wrapped into place on the skin.
Peel-away catheters are also very easy to place. They are not self-enclosed so sterility can be an issue. The peel-away catheter is similar to an over the needle catheter placement with a few additional steps. Once the peel-away over-the-needle catheter is placed, the stylet is removed leaving the catheter in the vessel. The catheter is then pushed through the catheter in the vessel. The over-the-needle catheter has two tabs on the proximal end near the hub of the needle; when the tabs are pulled the first catheter will split or peel away leaving just the central line catheter in the vessel. This method is not commonly used in practice but remains an option as a long-term central catheter.
Placement of Multi-lumen Jugular Catheter Using Seldinger Technique
Many times, in critical care medicine the placement of multi-lumen intravenous catheters is crucial to quality patient care. The central tube portion of a multi-lumen catheter has a cylindrical shape while internally it is divided into two or three separate lumens. With a triple lumen catheter, there are three separate exit ports through the central tube; distal, medial and proximal. This catheter is the most difficult to place of the central lines. Using a five-step process; over-the-needle catheter placement, guide wire, vasodilator, placement of the central line catheter and securing the catheter. This catheter usually requires patients to be sedated or under general anesthesia if they are not gravely ill because it usually takes 10-20 minutes to fully place this catheter. While this is a long and lengthy procedure, it is arguably the most stable and best central line catheter to place.
How to Place a Central Line:
Be sure to check out these amazing VETgirl videos on how to place a central line catheter!