Vascular Access Flashcards

What are the three main types of vascular access used in hemodialysis?

Answer: Arteriovenous fistula, AV graft, and central venous catheter

The three main types of vascular access used in hemodialysis are the arteriovenous (AV) fistula, the AV graft, and the central venous catheter. An AV fistula is a surgical connection between an artery and a vein, an AV graft uses a synthetic tube to connect them, and a central venous catheter is a tube inserted into a large central vein. Each type has distinct advantages and disadvantages for long-term or temporary use.

Which vascular access is considered the gold standard for long-term dialysis?

Answer: AV fistula

The arteriovenous (AV) fistula is considered the 'gold standard' for long-term hemodialysis access due to its superior outcomes. It has lower rates of infection and thrombosis, longer patency, and provides better blood flow compared to AV grafts and central venous catheters. It is formed by surgically connecting a patient's own artery and vein, allowing it to mature and strengthen over time.

Why should blood pressure and venipuncture be avoided in the arm with an AV fistula?

Answer: To avoid damaging the fistula

Blood pressure measurements and venipuncture should be avoided in the arm with an AV fistula to prevent damage to the delicate vascular access. Compressing or puncturing the fistula can lead to thrombosis, infection, or loss of patency, which would compromise the patient's ability to receive life-sustaining dialysis treatments. Preserving the fistula's integrity is paramount.

What is the correct method to assess an AV fistula?

Answer: Palpate for thrill and listen for bruit

Assessing an AV fistula involves both palpation and auscultation to confirm its patency and function. A 'thrill' is a palpable vibration felt over the fistula, indicating blood flow, and a 'bruit' is a whooshing sound heard with a stethoscope, also confirming adequate blood flow. The presence of a strong thrill and bruit indicates a healthy, functioning fistula.

How is a central venous catheter typically placed for dialysis?

Answer: Inserted into the internal jugular vein and tunneled

A central venous catheter for dialysis is typically inserted into a large central vein, most commonly the internal jugular vein in the neck. For long-term use, a portion of the catheter is then tunneled under the skin before exiting, which helps to reduce the risk of infection by creating a barrier and stabilizing the catheter.

What is a common complication of central venous catheters?

Answer: Infection

Infection is a common and serious complication of central venous catheters, particularly non-tunneled ones. Because the catheter provides a direct pathway for bacteria into the bloodstream, the external segment and insertion site are vulnerable to colonization, leading to local infections or potentially life-threatening bloodstream infections (sepsis). Strict aseptic technique is crucial to minimize this risk.

How often should vascular access sites be monitored during dialysis?

Answer: Before, during, and after dialysis

Vascular access sites are the patient's lifeline for dialysis, making continuous monitoring essential. Checking before, during, and after treatment allows for early detection of complications like infiltration, infection, or clotting. This proactive approach ensures the safety and effectiveness of the dialysis session and helps preserve the access for future use.

What is the purpose of rotating needle insertion sites on an AV fistula?

Answer: To prevent scarring and aneurysms

Rotating needle insertion sites prevents repeated trauma to the same area of the AV fistula. This practice reduces the risk of scarring, which can narrow the vessel, and the formation of aneurysms, which are dangerous bulges in the vessel wall. By distributing the insertion points, the fistula's integrity is maintained, prolonging its lifespan for effective dialysis.

Which sign indicates a problem with vascular access that needs immediate attention?

Answer: Absence of thrill or bruit

A thrill (palpable vibration) and a bruit (audible whooshing sound) are crucial indicators of adequate blood flow through a vascular access. Their absence suggests a potential problem like thrombosis (clotting) or stenosis (narrowing), which can compromise the access and prevent effective dialysis. Immediate attention is required to assess and address such issues to preserve the access.