When the kidneys do not function correctly, the doctor is left with no option but to put the patient on dialysis. The kidneys are involved in filtering the blood but this process 'goes for a toss' when they are damaged. The removal of wastes from the blood is crucial for the survival of the human body. So, medical intervention is necessary to filter out blood by some other means, which is nothing but dialysis. Dialysis catheter forms an indispensable part of dialysis.
A catheter is a flexible tube that is introduced into a blood vessel in order to remove fluid or administer medication intravenously. A dialysis catheter acts as a blood carrier between the part of the body (where it is inserted) and the filtration system (hemodialysis). However, unlike a normal catheter, a dialysis catheter is designed to have two tubes (lumens). One tube (arterial lumen) of catheter dialysis extracts blood from the body and moves it to hemodialysis machine for filtration, while the other tube (venous lumen) transports blood from the hemodialysis machine to the body. One can also decide the speed at which the blood can move from the catheter. In other words, the dialysis catheter can regulate the blood flow. The catheter can be adjusted to control the blood flow, which varies from 200 to 500 milliliters per minute.
Site of Insertion
The hemodialysis machine is sometimes referred to as artificial kidney as it effectively removes impurities from the blood. The machine definitely fulfills the kidney dialysis process. It does an excellent job when it comes to cleaning the blood that is eventually passed down to the patient through the dialysis catheter. Of course, the catheter cannot be inserted anywhere in the body to remove blood. The site of insertion is fixed and is usually the neck. The dialysis catheter is put in a large diameter vein around the neck area as it carries impure blood. The internal jugular vein in the neck area is usually selected to carry out the hemodialysis. In some cases, insertion site is the groin area and the blood vessels that are chosen to place dialysis catheter are the femoral veins.
Patients with severe kidney damage or complete loss of kidney function require dialysis on a regular basis. In such circumstances, chronic dialysis catheters are used that can be kept at the site of insertion for long periods of time (approximately 30 days). They are structurally designed in such a way that they do not cause any sort of infection. Although there are different dialysis catheters, the one that is used for hemodialysis is the catheter port that is surgically inserted under the skin to draw the blood. The port, also known as the drum, is the frontal part of the catheter that is connected to the large vein. This drum, which is under the skin has a partition that allows the doctor to administer medicine and draw blood. Chronic dialysis catheters, also referred to as tunneled catheters and placed 3-7 cm under the skin, come with a cuff that prevents infection and promotes tissue growth and ensures that the catheter does not get dislodged from the site of insertion. Some of the popular catheter brands in this category are 'Hickman', 'Broviac', 'Centros' and 'Groshong'. Catheters sold under the 'Centros' brand have two free tips, hence they are referred to as split tip dialysis catheter.
Use of dialysis catheter comes with its own set of disadvantages. There have been reports of insertion site developing an infection. Blood clots forming at the mouth of catheter (dialysis access points) are also common. This can cause reduction in the blood flow through the dialysis catheter. In some cases, the blood clot can completely stop the blood circulation. Dialysis catheter care guidelines like keeping the tube clean and ensuring that the clamps and caps of the catheter remain closed when the dialysis tube is not in use can go a long way in preventing these complications.