CHBT Vascular Access and Cannulation Basics

Question 1

Which type of vascular access is considered the 'gold standard' for long-term hemodialysis due to its superior patency and lower infection risk?

Accepted Answer

Arteriovenous fistula (AVF)

Answer

The AVF is the preferred access because it uses the patient's own vessels, resulting in lower rates of infection, thrombosis, and hospitalization compared to grafts or catheters. It also has the longest functional lifespan.

Question 2

What is the 'rope ladder' cannulation technique?

Accepted Answer

Rotating needle insertion sites along the entire length of the access, distributing puncture trauma evenly

Answer

The rope ladder technique rotates insertion sites systematically along the graft or fistula, preventing aneurysm formation at any single point by distributing puncture trauma over the full access length.

Question 3

Before cannulating an arteriovenous fistula, which assessment is essential?

Accepted Answer

Auscultating for a bruit and palpating for a thrill to confirm access patency

Answer

A bruit (audible flow sound by stethoscope) and thrill (palpable vibration) confirm the fistula is patent and functioning. Absence of either may indicate thrombosis or stenosis and must be reported before cannulation.

Question 4

What is the minimum maturation time typically required for an AVF before it can be used for hemodialysis?

Accepted Answer

At least 4–6 weeks (ideally 3–4 months)

Answer

An AVF requires a minimum of 4–6 weeks to mature (arterialization of the vein wall), but 3–4 months is preferred to allow adequate vessel dilation and wall strengthening for reliable cannulation.

Question 5

What is 'infiltration' in the context of vascular access cannulation?

Accepted Answer

Leakage of blood into surrounding tissue when a needle punctures through or outside the vessel wall

Answer

Infiltration (also called hematoma) occurs when the needle is misplaced outside the vessel, causing blood to leak into surrounding tissue. The needle must be removed, firm pressure applied, and the treatment may need to be postponed.

CHBT - Certified Hemodialysis Bio-Medical Technician Practice Test

CHBT - Certified Hemodialysis Bio-Medical Technician Practice Test

CHBT Vascular Access and Cannulation Basics