22 Vascular Access Practice Questions & Answers

1. 1. A patient is about to start hemodialysis. The surgeon has evaluated both arms and documented that there are no adequate blood vessels in the limbs to create a fistula or place a graft. Which vascular access is the technician most likely to see used for this patient?

   • A.A central venous catheter✓ Answer
   • B.A radiocephalic arteriovenous fistula in the forearm
   • C.A brachiocephalic arteriovenous fistula in the upper arm
   • D.A synthetic arteriovenous graft in the forearm

   A fistula and a graft both require usable peripheral arteries and veins in the limb. When the limbs have no adequate vessels, the only remaining route is a large central vein, so a central venous catheter is placed. The technician should still expect the team to keep working toward a permanent access, because a catheter carries the highest infection and bloodstream-infection risk and delivers the lowest blood flow.

   Source: NNCC CCHT Content Outline, Clinical practice area, vascular access activitiesReport a problem with this question

2. 2. A patient asks the technician why the surgeon recommended a fistula instead of the graft his neighbor has. Which explanation best reflects why a native arteriovenous fistula is generally the preferred access?

   • A.It cannot develop stenosis or aneurysm, so no routine access assessment is required
   • B.It is built entirely from the patient's own artery and vein, with an intact natural lining and no foreign material, so it resists infection and clotting better and tends to last longest✓ Answer
   • C.It requires only one needle each treatment, which cuts the number of punctures in half
   • D.It can be cannulated immediately after surgery, so no temporary catheter is needed

   A fistula is a direct surgical anastomosis between the patient's own artery and vein. Because the blood path stays lined with the patient's own endothelium and contains no synthetic material for bacteria to colonize, infection and thrombosis rates are lower and patency is longer than with a graft or catheter. A fistula still needs weeks to mature, still uses two needles, and still must be assessed every treatment.

   Source: ANNA Core Curriculum for Nephrology Nursing, vascular access; NNCC CCHT Content Outline, Clinical practice areaReport a problem with this question

3. 3. Which statement best describes an arteriovenous graft compared with an arteriovenous fistula?

   • A.The graft is a synthetic conduit sewn between an artery and a vein; it can usually be cannulated sooner than a fistula, but it clots more often and tends to narrow at the venous anastomosis✓ Answer
   • B.The graft is a direct anastomosis of an artery to a vein, and the fistula uses tubing
   • C.The graft must mature longer than a fistula before it can be cannulated
   • D.The graft is placed in a central vein and tunneled under the skin of the chest

   A graft bridges an artery and a vein with a synthetic conduit, so there is no vein that must enlarge first and it becomes usable sooner than a fistula, according to facility protocol. The trade-off is mechanical: turbulent flow where the stiff conduit meets the vein triggers intimal hyperplasia, so grafts narrow at the venous anastomosis and thrombose more often than fistulas.

   Source: Counts, Review of Hemodialysis for Nurses and Dialysis Personnel, vascular access chapterReport a problem with this question

4. 4. A hospitalized patient needs dialysis today and arrives with a catheter that was placed at the bedside; it has no cuff and no subcutaneous tunnel. What should the technician understand about this access?

   • A.Because it is temporary, it may also be used for routine blood draws and intravenous fluids
   • B.It is equivalent to a tunneled catheter and may remain in place indefinitely as long as the dressing is changed weekly
   • C.It is a temporary access for immediate, short-term use and carries a higher infection risk than a tunneled cuffed catheter, so planning for a permanent access should continue✓ Answer
   • D.It delivers higher blood flow than a fistula, so conversion to a permanent access is unnecessary

   A non-tunneled catheter exits the skin close to the vein entry point, so bacteria have a short, direct path along the catheter into the bloodstream; the cuff and tunnel of a long-term catheter add both distance and tissue ingrowth as a barrier. That is why non-tunneled lines are for acute, short-term use only, and why the plan for a fistula or graft continues.

   Source: CDC recommendations for preventing bloodstream infections in outpatient hemodialysis patients, catheter careReport a problem with this question

5. 5. A patient whose fistula was created three weeks ago asks why he still cannot be dialyzed through it. Which explanation describes what maturation physically accomplishes?

   • A.Time is needed for the anticoagulant used during surgery to be cleared from the access
   • B.Arterial pressure and flow must dilate the vein and thicken its wall so it is large enough, superficial enough and strong enough for repeated cannulation at the prescribed blood flow✓ Answer
   • C.Time is needed for the synthetic material to be incorporated by surrounding tissue
   • D.Time is needed for the surgical connection to close so the vein can hold pressure on its own

   Maturation is arterialization: once arterial pressure is delivered into the vein, the vein dilates and its wall remodels and thickens. A vein that has not undergone that change is too small and too fragile to support two needles and the prescribed blood flow, and premature cannulation causes infiltration and can destroy the access. The technician should refer the patient's question about readiness to the nurse.

   Source: ANNA Core Curriculum for Nephrology Nursing, arteriovenous fistula maturationReport a problem with this question

6. 6. A technician sees a new staff member wrapping a blood pressure cuff around the arm that holds the patient's fistula. What should the technician do first, and why?

   • A.Say nothing and document that a cuff was used on the access arm
   • B.Allow it, but tell the new staff member to place the cuff below the anastomosis
   • C.Stop the new staff member and have the pressure taken on the other arm, because inflating a cuff compresses the access, slows flow through it and can promote clotting or damage✓ Answer
   • D.Allow it, because a single reading is too brief to affect the access

   An access depends on continuous, unobstructed flow. Anything that compresses the limb — a blood pressure cuff, a tourniquet, tight clothing or jewelry, sleeping on the arm — slows that flow and raises the risk of thrombosis, and venipuncture or intravenous lines in the access arm add a risk of vessel injury and infection. Blood pressure is taken on the non-access arm.

   Source: NNCC CCHT Content Outline, Role Responsibilities, reinforcing patient education on access careReport a problem with this question

7. 7. Which self-care instruction should the technician reinforce with a patient who has a new arteriovenous fistula?

   • A.Feel the access for the thrill every day and call the dialysis unit right away if the thrill can no longer be felt✓ Answer
   • B.Allow small-gauge laboratory draws from the access arm as long as they are not from the fistula itself
   • C.Sleep on the access arm so the weight keeps the vein from moving
   • D.Wear a snug elastic wristband over the access to protect it between treatments

   The thrill is the palpable evidence that blood is still flowing continuously through the access. Loss of the thrill can mean the access has clotted, and a clotted access must be treated urgently if it is to be saved, so daily self-checks and immediate reporting matter. The other options all compress or puncture the access limb, which is exactly what access-arm precautions forbid.

   Source: NNCC CCHT Content Outline, Clinical practice area, post-dialysis access care and patient educationReport a problem with this question

8. 8. Before treatment, a technician assesses a forearm fistula. The skin looks normal with no redness, swelling or drainage, but no bruit can be heard with the stethoscope, no thrill is felt, and the access feels cool and firm. What is the most likely problem and the correct action?

   • A.The access is infected; cannulate a different site and report at the end of treatment
   • B.This is normal between treatments; proceed with cannulation and recheck afterward
   • C.The access is most likely clotted; do not cannulate and report the finding to the nurse immediately✓ Answer
   • D.The access infiltrated at the last treatment; apply warm packs and then cannulate

   The bruit is the sound of turbulent flow and the thrill is its palpable counterpart; both exist only while blood is moving through the access. An absent bruit and absent thrill therefore mean flow has stopped, which is thrombosis, and the cool firm feel supports it. Redness and swelling would point to infection or infiltration instead. Cannulating a clotted access can worsen the damage, so the technician stops and reports to the nurse.

   Source: NNCC CCHT Content Outline, Clinical activity: identify potential access failure by looking, listening and feelingReport a problem with this question

9. 9. On palpation of a fistula, the technician feels a strong, forceful pulse that pounds against the fingertips instead of the usual soft continuous vibration. What does this finding most likely indicate?

   • A.Steal syndrome, with arterial blood being diverted away from the hand
   • B.Normal findings in a fistula that has finished maturing
   • C.Outflow (venous) stenosis downstream, which is raising pressure inside the access; the technician should report the finding to the nurse✓ Answer
   • D.An inflow problem at the arterial anastomosis, which reduces pressure inside the access

   A thrill is produced by continuous forward flow. When the outflow is narrowed, blood cannot leave the access freely, so pressure builds and the arterial pulsation is transmitted instead of being smoothed into a thrill — the classic water-hammer pulse. Recognizing this early lets the nurse arrange evaluation before the access clots. An inflow problem lowers pressure and produces a weak, flat access, not a pounding one.

   Source: Counts, Review of Hemodialysis for Nurses and Dialysis Personnel, access assessment and stenosisReport a problem with this question

10. 10. A technician preparing to cannulate a graft finds the skin over the lower half of the graft red, warm and tender, with a small amount of purulent drainage at an old needle site. The patient mentions he felt chills last night. What is the most appropriate action?

    • A.Clean the drainage away with extra antiseptic and cannulate the usual site
    • B.Do not cannulate the access; report the findings to the nurse before treatment is started✓ Answer
    • C.Apply ice to the area to reduce the redness, then cannulate
    • D.Cannulate above the affected area and mention the drainage at the end of the shift

    Redness, warmth, tenderness, purulent drainage and chills together are signs of an access infection that may already be seeding the bloodstream. Puncturing an infected access drives organisms directly into the circulation and can cause a graft infection that costs the patient the access. The technician's role is to recognize the signs, hold off on cannulation and report to the nurse, who involves the physician.

    Source: CDC recommendations for preventing bloodstream infections in outpatient hemodialysis patients, vascular access careReport a problem with this question

11. 11. A patient has a loop graft in the forearm and the usual staff member is out. How should the technician determine which limb of the loop is the arterial side before cannulating?

    • A.Apply a tourniquet above the graft and see which limb fills first
    • B.Compress the graft at its midpoint and palpate on each side of the compression; the side with the stronger pulse or thrill is the arterial limb✓ Answer
    • C.Cannulate one limb and judge from the color of the blood that returns
    • D.The limb closer to the wrist is always the arterial limb in a forearm loop graft

    Compressing the graft blocks flow through it. Upstream of the block, arterial pressure is still being delivered, so that limb pulses strongly; downstream, the pulse and thrill fade because nothing is flowing in. The direction of the loop cannot be assumed from anatomy, and finding out by cannulating first risks a reversed setup and recirculation.

    Source: NNCC CCHT Content Outline, Clinical activity: cannulate the vascular accessReport a problem with this question

12. 12. In which direction should the venous (return) needle be placed in a fistula, and why?

    • A.Antegrade, pointing toward the heart in the direction of blood flow, so returned blood moves away from the arterial needle instead of being pulled back into the dialyzer✓ Answer
    • B.Directly into the anastomosis, where the vessel is largest and least likely to infiltrate
    • C.Retrograde, pointing back toward the anastomosis, so returning blood is mixed at the inflow
    • D.Either direction is acceptable as long as both needles are in the same segment of the fistula

    The venous needle returns cleaned blood, and blood in the access travels from the anastomosis toward the heart. Pointing the venous needle with that flow, downstream of the arterial needle and adequately separated from it, means the returned blood is carried away rather than immediately re-aspirated. Pointing it backward or placing the needles too close together creates recirculation, which lowers the effective dose of dialysis.

    Source: ANNA Core Curriculum for Nephrology Nursing, cannulation technique and recirculationReport a problem with this question

13. 13. Midway through a treatment, a technician discovers that the arterial and venous bloodlines were connected to the wrong needles. What is the main consequence of this error?

    • A.The ultrafiltration rate is doubled and the patient will become hypotensive
    • B.Air is introduced into the circuit through the reversed connection
    • C.Blood that has just been returned is pulled straight back into the dialyzer, so the same blood is cleaned repeatedly, the delivered dose of dialysis falls, and post-treatment laboratory clearance can look falsely good✓ Answer
    • D.No real consequence, since both needles are in the same access

    Reversing the lines makes the uptake needle sit downstream of the return needle, so a portion of already-dialyzed blood is drawn immediately back into the circuit. Because that blood has low solute concentration, the dialyzer is fed cleaner blood than the body actually contains: real clearance drops while the numbers can look deceptively favorable. The technician corrects the setup per protocol and reports the event to the nurse for documentation.

    Source: Counts, Review of Hemodialysis for Nurses and Dialysis Personnel, access recirculationReport a problem with this question

14. 14. Which statement about buttonhole (constant-site) cannulation is correct?

    • A.Buttonhole is used only in fistulas; sharp needles create the track, blunt needles are used once the track has matured, and the scab must be removed aseptically before each cannulation✓ Answer
    • B.Buttonhole is the preferred technique for synthetic grafts because the material seals around the track
    • C.Blunt needles are used from the very first cannulation so the tissue is never cut
    • D.Because the same site is used every time, skin antisepsis is less important than with rope-ladder cannulation

    The buttonhole depends on a healed scar tunnel through living tissue, which synthetic graft material cannot form, so it is for fistulas only. Sharp needles establish the tunnel at the same site, angle and depth every time; once the track is mature, blunt needles follow it without cutting new tissue. Because a fixed track is a repeated portal into the bloodstream and the scab harbors organisms, buttonhole carries a higher infection risk and demands stricter, not looser, antisepsis.

    Source: NNCC CCHT Content Outline, Clinical activity: cannulate a mature buttonhole accessReport a problem with this question

15. 15. A fistula has developed a bulging, dilated segment in the area where staff have repeatedly placed needles within a one-inch zone. What best explains this finding and what change in practice is indicated?

    • A.The needle gauge used was too large for the fistula; a smaller-bore needle will let the dilation resolve
    • B.Too much anticoagulant was given during treatments, allowing the vessel to stretch
    • C.This is normal continued maturation of the fistula and no change in cannulation practice is needed
    • D.Repeated punctures in one small area weakened the vessel wall and produced an aneurysm; sites should be rotated along the whole usable length of the access✓ Answer

    Area (one-site) puncture destroys the same short stretch of vessel wall over and over, and scar-weakened wall balloons out under arterial pressure — an aneurysm in a fistula, a pseudoaneurysm in a graft. Rope-ladder rotation spreads the trauma over the whole usable length so no segment is destroyed. Skin over an aneurysm that is shiny, thin, ulcerated or scabbed must never be cannulated and must be reported, because rupture is an exsanguination risk.

    Source: Counts, Review of Hemodialysis for Nurses and Dialysis Personnel, cannulation site rotation and aneurysmReport a problem with this question

16. 16. Shortly after blood is started, the tissue around the venous needle swells rapidly, the patient reports burning and pain at the site, the skin is discolored, and the venous pressure alarm sounds. What should the technician do FIRST?

    • A.Stop the blood pump and clamp the lines so nothing further is infused into the tissue, then notify the nurse✓ Answer
    • B.Increase the blood flow rate to push blood past the obstruction
    • C.Add more tape to secure the needle and continue the treatment
    • D.Apply a warm pack over the swelling and continue the treatment

    These findings describe infiltration: the needle has passed through the vessel wall and blood is being pumped into the surrounding tissue. Every additional second of pumping enlarges the hematoma and the tissue damage, so the pump is stopped and the lines clamped before anything else. The nurse is then notified; ice is generally applied for the first day and the site is managed and documented according to facility protocol.

    Source: NNCC CCHT Content Outline, Clinical activity: recognize and respond to complications of cannulationReport a problem with this question

17. 17. After the treatment ends, how should the technician remove the needles and achieve hemostasis?

    • A.Apply a mechanical clamp tightly over both sites so staff are free to attend other patients
    • B.Hold for about one minute and then apply a tight pressure dressing for the patient to keep on overnight
    • C.Withdraw the needle completely at the same angle it was inserted, then hold with two fingertips over both the skin and the vessel puncture sites, firmly enough to stop bleeding but not so firmly that the thrill is lost✓ Answer
    • D.Press firmly on the site while the needle is being withdrawn so bleeding never starts

    Pressing while the needle is still in drags the bevel through the vessel wall and lacerates it, so pressure begins only after the needle is fully out and follows the same track angle. The skin hole and the vessel hole are not in the same plane, so both must be compressed. Pressure hard enough to obliterate the thrill stops flow through the access and invites clotting, which is also why tight clamps and constricting dressings are avoided. Bleeding that continues well beyond the usual time is reported to the nurse.

    Source: NNCC CCHT Content Outline, Clinical activity: post-dialysis fistula and graft access careReport a problem with this question

18. 18. A patient with a recently created upper-arm access reports that during treatment his hand on that side becomes cold, pale and numb, with aching pain. The access itself has a good thrill and bruit. What does this suggest and what should the technician do?

    • A.Steal syndrome, in which arterial blood is diverted through the access and the hand becomes ischemic; report the findings to the nurse promptly✓ Answer
    • B.Infiltration of the arterial needle; the needle should be removed and replaced distally
    • C.Venous stenosis; the blood flow rate should be reduced and the treatment continued without further comment
    • D.An expected sensation while a new access matures; reassure the patient that it will resolve

    An access is a low-resistance shortcut from artery to vein, so blood can preferentially flow into it instead of continuing to the hand. The result is distal ischemia: coldness, pallor or bluish nail beds, numbness, tingling, weakness and pain that is often worst during dialysis, when flow through the access is highest. Untreated it can progress to ulceration and tissue loss, and correction is surgical, so the technician reports promptly rather than reassuring the patient.

    Source: ANNA Core Curriculum for Nephrology Nursing, vascular access complications, dialysis access steal syndromeReport a problem with this question

19. 19. During a treatment at an unchanged blood pump speed, the venous pressure has climbed steadily from 140 mmHg to 260 mmHg over the past hour, and dark streaking is visible in the venous drip chamber. What does this change most likely indicate?

    • A.Recirculation, which is corrected by reversing the arterial and venous lines
    • B.Inadequate arterial inflow, which is corrected by increasing the blood pump speed
    • C.A fall in the patient's blood pressure, which raises pressure on the venous side of the circuit
    • D.An obstruction to outflow — clotting in the circuit or access, a kink, a needle against the vessel wall, or venous stenosis; the technician should assess the circuit per protocol and report the finding to the nurse✓ Answer

    Venous pressure is measured on the return side, so it reflects how easily blood can leave the circuit and enter the access. Anything narrowing that path raises the pressure needed to push the same flow through, which is why a rising venous pressure at an unchanged pump speed points downstream, and the dark streaking suggests clot forming. An inflow problem shows up instead as a low or strongly negative arterial pressure. The technician checks and reports; the nurse and physician decide on evaluation of the access.

    Source: NNCC CCHT Content Outline, Clinical activity: recognize and report signs of access failure such as stenosis and clottingReport a problem with this question

20. 20. A technician cleans the cannulation site with antiseptic and lets it dry completely. Just before inserting the needle, the technician palpates the prepared skin once more to confirm the vessel's path. What should be done next?

    • A.Proceed with the puncture, since clean gloves were worn during palpation
    • B.Wipe the site with dry gauze and then puncture
    • C.Repeat the skin antisepsis and let it dry again before puncturing, because touching the prepared skin recontaminates it✓ Answer
    • D.Re-prep only if the patient did not wash the access arm before treatment

    Skin antisepsis works only if the disinfected surface stays untouched until the needle goes in; gloves are not sterile and a fingertip re-deposits organisms onto the site. The antiseptic must also be allowed its full contact time and be dry before puncture, since it kills organisms during that contact, not on contact. Cannulation drives whatever is on the skin directly into the bloodstream, which is why this step is not shortened.

    Source: CDC recommendations for preventing bloodstream infections in outpatient hemodialysis patients, skin antisepsis before accessReport a problem with this question

21. 21. A patient with a tunneled hemodialysis catheter arrives with a damp, loose dressing. The exit site is red and tender with crusted drainage, and the patient says he got shaking chills soon after the pump was started at the last treatment. What is the most appropriate action?

    • A.Report the findings to the nurse immediately, because they suggest an exit-site infection with possible bloodstream infection✓ Answer
    • B.Flush both lumens vigorously to clear any organisms from the catheter
    • C.Do nothing, since chills at the start of treatment are an expected response to cool dialysate
    • D.Apply extra antimicrobial ointment and change the dressing at the next visit

    Redness, tenderness and drainage at the exit site are local signs of infection, and rigors that begin shortly after the pump starts suggest organisms from the catheter are being flushed into the circulation. A catheter is a direct highway into a central vein, so suspected catheter infection is escalated at once for the nurse and physician to assess, obtain cultures and order treatment. Flushing forcefully could push organisms and clot into the bloodstream. A damp, loose dressing must be changed using aseptic technique, not left in place.

    Source: CDC Core Interventions for Dialysis Bloodstream Infection Prevention, catheter exit site careReport a problem with this question

22. 22. Which set of practices is correct when a technician connects and disconnects a patient's hemodialysis catheter?

    • A.The technician and the patient both wear a mask, the hubs are disinfected every time the catheter is accessed or disconnected, and the lock solution is aspirated rather than flushed into the patient✓ Answer
    • B.Caps may be left off between connection and disconnection to save time, as the lumens are clamped
    • C.The catheter may also be used for routine laboratory draws and intravenous fluids, since it is already in a central vein
    • D.The lock solution is flushed into the patient at the start of treatment so none of the dose is wasted

    A catheter is managed as a closed system because its lumens open directly into a central vein. Masks on both staff and patient keep respiratory organisms off the open hubs, hub disinfection at every access removes organisms that would otherwise be pushed inward, and the lock is aspirated because it is a concentrated anticoagulant or citrate solution meant to stay in the catheter, not to enter the patient. Extra uses of the lumens add extra entries and extra infection risk, so they follow facility policy and a physician's order.

    Source: CDC Core Interventions for Dialysis Bloodstream Infection Prevention, catheter connection and hub disinfectionReport a problem with this question

Practice questions based on the NNCC CCHT content outline, CDC recommendations for hemodialysis settings, and the OSHA Bloodborne Pathogens Standard. Not affiliated with or endorsed by NNCC, and not medical advice. Machine settings, dialysate composition, flow rates, alarm thresholds, water-quality limits and laboratory targets are deliberately never the answer to a question here — those are set by your machine's manufacturer, your facility's protocol and the physician's prescription. Always follow your facility's policies and your patient's prescribed treatment. About the CCHT exam (NNCC) →