A dialysis catheter is a catheter

Catheter

In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments. The process of inserting a catheter is catheterization...

 used for exchanging blood

Blood

Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 to and from the hemodialysis

Hemodialysis

In medicine, hemodialysis is a method for removing waste products such as creatinine and urea, as well as free water from the blood when the kidneys are in renal failure. Hemodialysis is one of three renal replacement therapies .Hemodialysis can be an outpatient or inpatient therapy...

 machine from the patient.

The dialysis catheter contains two lumen

Lumen (anatomy)

A lumen in biology is the inside space of a tubular structure, such as an artery or intestine...

s:

• Venous
• Arterial

This is a confusing terminology for layperson, because both lumens are in the vein. The arterial lumen (typically red) withdraws blood from the patient and carries it to dialysis

Dialysis

In medicine, dialysis is a process for removing waste and excess water from the blood, and is primarily used to provide an artificial replacement for lost kidney function in people with renal failure...

 machine, while the venous lumen (typically blue) returns blood to the patient (from the dialysis machine). Flow rates

Volumetric flow rate

The volumetric flow rate in fluid dynamics and hydrometry, is the volume of fluid which passes through a given surface per unit time...

 of dialysis catheters range between 200 to 500 ml/min.

If a patient requires long-term dialysis therapy, a chronic

Chronic (medicine)

A chronic disease is a disease or other human health condition that is persistent or long-lasting in nature. The term chronic is usually applied when the course of the disease lasts for more than three months. Common chronic diseases include asthma, cancer, diabetes and HIV/AIDS.In medicine, the...

 dialysis catheter will be inserted. Chronic catheters contain a dacron cuff that is tunneled beneath the skin approximately 3–8 cm. The tunnel is thought to add a barrier to infection. The most popular dialysis catheter sold on the market

Market

A market is one of many varieties of systems, institutions, procedures, social relations and infrastructures whereby parties engage in exchange. While parties may exchange goods and services by barter, most markets rely on sellers offering their goods or services in exchange for money from buyers...

 today is the split-tip dialysis catheter. This catheter comprises two free floating tips.

Catheter placement

The catheter is placed in one of the large vein

Vein

In the circulatory system, veins are blood vessels that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart...

s. A common site is superior vena cava

Superior vena cava

The superior vena cava is truly superior, a large diameter, yet short, vein that carries deoxygenated blood from the upper half of the body to the heart's right atrium...

 or SVC. An SVC catheter is placed by puncturing the internal jugular vein

Internal jugular vein

The two internal jugular veins collect the blood from the brain, the superficial parts of the face, and the neck.-Path:On both sides and at the base of the brain, the inferior petrosal sinus and the sigmoid sinus join to form the internal jugular vein...

 in the neck

Neck

The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...

 (most often on the right side), and the catheter is then advanced downwards toward the chest. Alternatively an SVC catheter can be inserted via subclavian vein

Subclavian vein

The subclavian veins are two large veins, one on either side of the body. Their diameter is approximately that of the smallest finger.-Path:Each subclavian vein is a continuation of the axillary vein and runs from the outer border of the first rib to the medial border of anterior scalene muscle...

s right behind the clavicle

Clavicle

In human anatomy, the clavicle or collar bone is a long bone of short length that serves as a strut between the scapula and the sternum. It is the only long bone in body that lies horizontally...

 (the collar bone), often on the right. If the access of SVC is difficult, the femoral vein

Femoral vein

In the human body, the femoral vein is a blood vessel that accompanies the femoral artery in the femoral sheath. It begins at the adductor canal and is a continuation of the popliteal vein...

s can be used. This is an inferior option, however, because the groin

Groin

In human anatomy, the groin areas are the two creases at the junction of the torso with the legs, on either side of the pubic area. This is also known as the medial compartment of the thigh. A pulled groin muscle usually refers to a painful injury sustained by straining the hip adductor muscles...

 site is more prone to infection

Infection

An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...

 and also because patient cannot sit upright.

Complications

Some common malfunctions of dialysis catheters include: clotting, infection, and kinking. One of the most common errors of tunnel hemodialysis catheter insertions is failure to locate the arterial limb of the catheter medially and the venous limb laterally. This must be done, due to the fact that most catheters have a memory in the plastic, which will cause the catheter to try to resume it's natural straight form. If the arterial limb is placed laterally, this will cause the arterial inlet to float up against the vein wall, or even up against the rim of the inlet of the atrium. This has the same effect as your vacuum cleaner hose sucking up against your curtains. This results in poor blood flows, and can force the dialysis staff to reverse flow, using the venous limb of the catheter as the arterial. This will result in more inefficient dialysis, as there will be add-mixing of blood from the catheter (cleaning the same blood, over again).

Fistulas versus catheters

Surgically created arteriovenous fistulas

Cimino fistula

A Cimino fistula, also Cimino-Brescia fistula, surgically created arteriovenous fistula and arteriovenous fistula , is a type of vascular access for hemodialysis...

 are preferred over catheters for patients with chronic renal failure, as the risk of infections (e.g. endocarditis

Endocarditis

Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves . Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or even on intracardiac devices...

, bacteremia

Bacteremia

Bacteremia is the presence of bacteria in the blood. The blood is normally a sterile environment, so the detection of bacteria in the blood is always abnormal....

), hospitalization and death

Death

Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....

are lower. One of the most common errors of tunnel hemodialysis catheter insertions is failure to locate the arterial limb of the catheter medially and the venous limb laterally. This must be done, due to the fact that most catheters have a memory in the plastic, which will cause the catheter to try to resume it's natural straight form. If the arterial limb is placed laterally, this will cause the arterial inlet to float up against the vein wall, or even up against the rim of the inlet of the atrium. This has the same effect as your vacuum cleaner hose sucking up against your curtains. This results in poor blood flows, and can force the dialysis staff to reverse flow, using the venous limb of the catheter as the arterial. This will result in more inefficient dialysis, as there will be add-mixing of blood from the catheter (cleaning the same blood, over again).