NursingCrib.com

Posted: 28 Jun 2011 11:17 PM PDT

Definition

An arteriovenous (AV) fistula is established to provide access to the circulatory system for hemodialysis. It is created by connecting a vein to an arterial wall using the vessels of the patient. For a patient who is expected to be on a long-term dialysis, this type of access to the circulatory system is preferred. An AV fistula is composed of two segments of tubing connected in a U-shape to redirect blood from an artery to a vein.

Site of AV Fistula

One of the common complications of an AV fistula is clotting resulting to impaired patency of the fistula. This is the main reason why the recommended site for AV fistula insertion is on the wrist or elbow because fistula in these spots poses a lower risk to clotting and has the highest incidence of remaining patent.

If problems in insertion at the preferred sites is not possible circulatory system can be accessed through the utilization of an AV graft of synthetic material or a transposed brachial basilica vein fistula. Central venous catheters that are cuffed and tunneled should be discouraged to be used as permanent vascular access because they have more complications than AV access and a shorter life.

Enhancing Maturation of the Graft Site

It takes 3 to 4 months for the fistula to mature. Thus, while waiting for the time the fistula reaches maturity, a tunneled cuffed catheter may be used to temporarily provide patient's needs of vascular access in dialysis. When fistula is used before it reaches maturity, risk of having early venous stenosis is increased.

The following are the recommended activity to enhance the maturation of the graft site: (M-A-P)

M – Major venous side branchers may be selectively obliterated as doing so speeds up the maturation of an AV fistula that is maturing slowly.

A – Arm and hand with fistula should be exercised such as squeezing a rubber ball to increase blood flow.

P – Place the affected extremity to rest until the swelling subsides if the new AV fistula is infiltrated.

In cases where the patient has swelling at the AV fistula after 2 weeks a venogram or other contrast study should be performed on the AV access site to evaluate the central veins.