How is blood removed and replaced?
In order to do hemodialysis, there must be some type of access to the blood. The doctor will discuss the best type of access for each person.
There are three primary types of access:
- Fistula: A fistula is the preferred option for an access due to fewer complications and better patient outcomes. It is the direct linking of an artery to a vein, and allows for access to the blood for dialysis using two needles. It requires a surgical procedure, typically performed by a vascular surgeon and is usually placed in a patient’s non-dominant arm. The access takes up to six weeks to heal and mature before dialysis can begin. The advantages of using a fistula are:
- Higher blood flow, which means more efficient and effective dialysis
- Lower infection rates because there are no foreign materials involved
- Lower risk of blood clot formation
Complications are few, but can include the possibility of an aneurysm, or a weakness in the wall of the blood vessel, forming at the site of the fistula or cold hand or fingers. Tell your physician or renal care team if any complications or concerns arise.
- Graft: Also created in an outpatient surgical procedure, a graft uses special tubing or donated vein to connect the artery to a vein. The advantages of a graft include:
- Grafts may be placed in an arm or thigh
- They typically heal faster than a fistula, so patients can undergo dialysis sooner
Risks include infection and narrowing of the vein where the graft is attached.
- Venous catheter: When you need a more immediate, temporary access for dialysis, doctors will consider placing a catheter. A venous catheter is typically placed in your chest, near your collar bone. This type of access is considered for short-term or emergency use. The advantages of a venous catheter are:
- It’s a viable option for those whose kidney disease has progressed so rapidly that the time delay of healing from a fistula or graft is not an option.
- It can be used in patients who have problems with their fistula or graft.
Complications can include infections, narrowing of the veins and a higher risk of blood clots.
Caring for your access site
Once your dialysis access has been placed, you will need to take precautions to avoid problems.
- Avoid anything that puts pressure on your access, including tight clothing, jewelry, or a purse.
- Avoid picking up anything over 10 lbs; for example heavy groceries or objects.
- Avoid sleeping on the access area.
- Do not let anyone draw blood from your access or use that arm for checking your blood pressure.
With any access, you should carefully watch for any signs of problems, including redness, drainage or signs of infection.
Any of these should immediately be discussed with your renal care team. Your nurse will teach you how to check your access several times a day.
This may include placing your fingertips over the access site to feel for a rushing sensation, called a thrill. You can also learn to listen for a rushing noise, or bruit, through a stethoscope.