Vascular Access: Your Lifeline to Hemodialysis
Before beginning hemodialysis treatment, a person needs an access to their bloodstream, called a vascular access. The access allows the patient’s blood to travel to and from the dialysis machine at a large volume and high speed so that toxins, waste and extra fluid can be removed from the body.
There are two types of vascular access:
- Arteriovenous (AV) fistula
- Arteriovenous (AV) graft
The fistula and graft are permanent accesses placed under the skin. When patients find out they are in the advanced stages of chronic kidney disease and will need dialysis, their nephrologist will advise them to get a fistula or graft. Having the access in place well before beginning dialysis will give this lifeline time to "mature," so it can be ready to use.
When patients suddenly discover they have kidney failure, a catheter may be placed to allow for immediate dialysis treatment. The catheter will be used until a fistula or graft has time to mature.
An AV fistula is created by directly connecting a person’s artery and vein—usually in the arm. This procedure may be performed as an outpatient operation using a local anesthetic. As blood flows to the vein from the newly connected artery, the vein grows bigger and stronger. The patient is taught to do exercises—such as squeezing a rubber ball—to help the fistula mature for use. This takes six weeks to four months. Once the fistula has matured, it can provide good blood flow for many years of hemodialysis.
The benefits of a fistula compared to other access types include:
- lower risk of infections
- lower risk of forming clots
- performs better
- allows for greater blood flow
- lasts longer, sometimes even for decades if well-cared for
Some of the drawbacks include:
- the appearance of bulging veins at the access site
- taking several months for a new one to mature
- not maturing (in some cases)
Not everyone may be able to have a fistula due to various conditions; discuss your access options with your doctor, but ask for a fistula first.
The AV graft is similar to a fistula, in that it connects the artery and vein under the skin, except that a manmade tubing connects the artery and vein. It’s about one-half inch in diameter and is made from a type of Teflon or Gore-Tex material. Transplanted animal or human vessels may also be used as grafts. They’re usually placed in the arm, but can also be placed in the thigh.
Grafts don’t require as much time to mature as fistulas, because they don’t need time to enlarge before using. Usually a graft can be used about two to six weeks after placement. Because grafts are created from materials outside of the body, they tend to have more problems than fistulas due to clotting and infections and may need to be repaired or replaced each year.
Caring for a fistula or graft
Here are things you can do to take care of your access.
1) Keep your access area clean and free of any trauma. Your dialysis care team will teach you how to carefully wash it before each treatment. Look for signs of infection,including pain, tenderness, swelling or redness around your access area. Also, be aware of any fever and flu-like symptoms. If you do get an infection and catch it early, it can usually be treated with antibiotics.
2) Protect your access from any restriction or trauma by:
- avoiding tight clothes, jewelry or anything that puts pressure on your access
- not sleeping on top of or resting on your access area
- refraining from carrying bags or heavy items across your access area
- requesting that blood be drawn from your non-access arm
- requesting that blood pressure be taken from your non-access arm
Learn to feel the vibration of blood going through your access and check it several times a day. Call your dialysis care team immediately if the flow stops or changes, as this could be a blood clot has formed and needs to be treated.
Learn to listen with a stethoscope to the sound of blood flowing through your access. If the sound changes to a higher pitch, like a whistle, it could be an indication that blood vessels are narrowing. Call your dialysis care team if you notice any change in your access.
3) Prevent tearing or damage to your access by paying attention to the needle stick locations when you’re being put on dialysis. The arterial and venous needle tips should be at least two inches apart from each other, as well as away from access surgical scars. The new needle stick sites should be at least one-fourth inch from the sites used the time before. Allow about two weeks for healing of previous sites to help maintain the health of the access.
Ask your nephrologist and dialysis care team about numbing creams to reduce the pain and fear of needle sticks.
Many patients find they prefer having control of the needle stick process (self-cannulation). When you self-cannulate, you can control and participate in this part of your vascular access care and treatment. Ask your care team about training.
After treatment, your needles will be removed and you will need to apply pressure with sterile gauze over your needle sites to stop the bleeding. Your team will provide you with clean gloves and teach you the proper procedures to stop bleeding as well as prevent infection.
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