Vascular Access Flashcards
6 cards from real CCHT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Vascular Access flashcards as text
What is the buttonhole (constant site) cannulation technique, and what is its primary risk compared to the rope ladder method?
Answer: Inserting needles into the same track repeatedly to create a permanent blunt-needle cannulation site; risk is higher infection rate
Buttonhole cannulation creates a permanent subcutaneous track for blunt needle insertion, reducing cannulation pain, but carries a significantly higher infection risk than rope ladder.
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?
Answer: Reduce pump speed to 100 mL/min, assess needle position, check for needle in graft wall or positional issues, and notify the nurse
Excessively negative arterial pressure at low blood pump speed indicates a problem with blood delivery: needle malposition, kinked line, inadequate access, or access stenosis.
What is a pseudoaneurysm (false aneurysm) of an arteriovenous fistula, and how does it differ from a true aneurysm?
Answer: Pseudoaneurysm is a pulsatile hematoma outside the vessel wall contained by fibrous tissue; true aneurysm involves all wall layers
A pseudoaneurysm results from a vessel wall defect with blood escaping into tissue and being contained by a fibrous capsule, not the actual vessel wall layers.
What assessment finding during hemodialysis most strongly suggests that a patient's AVG has developed significant stenosis at the venous anastomosis?
Answer: Progressively increasing venous pressures over multiple treatments with reduced blood flow rates
Rising venous pressures over time indicate increasing outflow resistance, most commonly from stenosis at or near the venous anastomosis of an AVG.
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?
Answer: Risk of spontaneous graft rupture or erosion; do not cannulate the area and refer immediately to vascular surgery
Skin erosion or thinning over an AVG indicates the graft is eroding through the skin, a surgical emergency; the graft must not be cannulated and immediate surgical evaluation is required.
What is the steal phenomenon in the context of vascular access, and which patient population is at highest risk?
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
Steal syndrome occurs when the low-resistance AV access preferentially carries blood flow away from the hand/fingers; diabetics and those with peripheral vascular disease are at highest risk due to pre-existing distal ischemia.