Doppler and color-flow ultrasound are useful tools in the management of patients with vascular access devices, including those on hemodialysis who rely on either an arteriovenous (AV) fistula or an AV graft to create an alternative blood circulation. Patients with AV access devices have unique needs, and these diagnostic tools are useful to monitor the flow through the fistulas or grafts, particularly when medical complications occur that may compromise the structure or function of the fistula or graft. This article focuses on three common situations that require a high level of care and monitoring: thrombosis, bleeding, and infection.
WHY DO PATIENTS WITH ARTERIOVENOUS (AV) SHUNT FISTULAE REQUIRE CAREFUL MONITORING
AV fistulae are used as a conduit to provide hemodialysis access. The flow of dialysate must be maintained above a certain level to allow adequate hemodialysis. This can be monitored with a doppler or color-flow ultrasound to assure that the fistula is not clogged.
HOW DOPPLER ULTRASOUND WORKS TO ASSESS AV SHUNT VESSELS
Patients with AV shunt vessels are monitored with Doppler ultrasound to ensure that the flow is above a certain level. This requires special training, which can be completed as part of a fellowship program. The type of ultrasound probe needed is called an ultrasonic transducer. The transducer is applied over the area being examined with the help of a gel or water to improve contact between the probe and the skin. Once the probe is properly positioned, sound waves are transmitted into deep structures within the body using high-frequency vibrations, then reflected to create an image on a monitor. Ultrasound uses sound waves at frequencies greater than 20,000 hertz (cycles per second) to produce images of structures inside the body without surgery or x-rays.
WHAT ARE THE DIFFERENT SIGNS OF AV SHUNT MALFUNCTION?
The AV shunt is a surgery that diverts blood from the person’s body to the abdomen. It should function like a valve, but if the shunt malfunctions, it can cause serious complications. Here are some signs of AV shunt malfunction:
1) Decrease in one or more electrolytes such as sodium, potassium, calcium, or magnesium; 2) Sudden increase in blood volume; 3) High blood pressure or swelling; 4) Difficulty breathing; 5) Severe fatigue.
If you are a dialysis patient with a fistula in Alamogordo, NM, our team at Dialysis Management Alamogordo can help. We provide monitoring as well as assistance to ensure your fistula does not become clogged or lose flow. To schedule an appointment, give us a call at https://dizipost.com/