CCHT Vascular Access 3

Question 1

What is the buttonhole (constant site) cannulation technique, and what is its primary risk compared to the rope ladder method?

Accepted Answer

Inserting needles into the same track repeatedly to create a permanent blunt-needle cannulation site; risk is higher infection rate

Answer

A technique using a button-shaped needle for reduced pain; risk is higher infiltration rate

Answer

A technique for very small fistulas using pediatric needles; risk is lower blood flow

Answer

A technique only for experienced nurses; risk is limited availability

Question 2

How should a dialysis technician respond if blood flow from a newly cannulated AVF immediately reads -250 mmHg arterial pressure at a blood pump speed of only 200 mL/min?

Accepted Answer

Reduce pump speed to 100 mL/min, assess needle position, check for needle in graft wall or positional issues, and notify the nurse

Answer

Increase the pump speed to overcome the resistance

Answer

Accept -250 mmHg as normal for new fistulas

Answer

Switch to the venous needle as the arterial access

Question 3

What is a pseudoaneurysm (false aneurysm) of an arteriovenous fistula, and how does it differ from a true aneurysm?

Accepted Answer

Pseudoaneurysm is a pulsatile hematoma outside the vessel wall contained by fibrous tissue; true aneurysm involves all wall layers

Answer

Pseudoaneurysm involves all three vessel wall layers; true aneurysm is contained by fibrous tissue only

Answer

They are clinically identical and managed the same way

Answer

Pseudoaneurysms only occur in arteriovenous grafts

Question 4

What assessment finding during hemodialysis most strongly suggests that a patient's AVG has developed significant stenosis at the venous anastomosis?

Accepted Answer

Progressively increasing venous pressures over multiple treatments with reduced blood flow rates

Answer

Lower than usual arterial pressures

Answer

Decreased blood pump speed alarm frequency

Answer

Lower ultrafiltration rates

Question 5

A patient with a forearm loop AVG has an area of thinned, shiny skin directly over the graft material. What is the clinical concern and appropriate action?

Accepted Answer

Risk of spontaneous graft rupture or erosion; do not cannulate the area and refer immediately to vascular surgery

Answer

Normal skin changes over synthetic graft material; document and monitor

Answer

This indicates good incorporation of the graft; proceed with cannulation

Answer

Apply topical antibiotic ointment and continue cannulating the area

Question 6

What is the steal phenomenon in the context of vascular access, and which patient population is at highest risk?

Accepted Answer

Diversion of arterial blood flow away from the distal extremity by the low-resistance access, causing ischemia; highest risk in diabetics and elderly with peripheral vascular disease

Answer

Blood stealing from the circuit due to high blood pump speeds

Answer

Access blood flow stealing from cardiac output causing hypotension

Answer

A complication only seen with central venous catheters