22 Vascular Access Practice Questions & Answers

1. 1. A patient asks why the surgeon recommends a native arteriovenous fistula instead of a synthetic graft. Which explanation is most accurate?

   • A.A fistula is built from the patient's own vessels, so it tends to stay open longer and infect less.✓ Answer
   • B.A fistula uses synthetic tubing that resists clotting better than the patient's own vein does.
   • C.A fistula carries less blood flow than a graft, which is what protects it from clotting and infection.
   • D.A fistula can be cannulated within days of surgery, while a graft must wait for the vein to enlarge.

   A fistula joins the patient's own artery and vein, so there is no foreign material for bacteria to colonize and the whole channel is lined by the patient's own endothelium. That is the mechanism behind its lower infection rate and longer patency, which is why the fistula sits at the top of the access hierarchy.

   Source: KDOQI Clinical Practice Guideline for Vascular Access, access selection hierarchyReport a problem with this question

2. 2. A patient's forearm veins are small and scarred from years of intravenous therapy and cannot support a fistula. Which access is the surgeon most likely to create?

   • A.A native arteriovenous fistula, because scarred veins enlarge normally once arterial pressure reaches them.
   • B.An arteriovenous graft, because the synthetic conduit can bridge an artery to a usable deeper vein.✓ Answer
   • C.A non-tunneled temporary catheter, because it can be left in place for as long as the patient needs it.
   • D.A tunneled cuffed catheter, because a permanent access can no longer be created in either arm.

   A graft is chosen when the patient's own superficial veins are too small, scarred or deep to mature into a fistula, because the synthetic conduit itself carries the blood between an artery and a deeper suitable vein. A scarred vein will not arterialize normally, and a catheter is reserved for when no permanent access can be built or used yet.

   Source: ANNA Core Curriculum for Nephrology Nursing, vascular access selectionReport a problem with this question

3. 3. A patient who has never had dialysis arrives needing treatment the same day. Which statement best explains the role of a central venous catheter for this patient?

   • A.It carries less infection risk than a graft and serves as a permanent access.
   • B.It should go in the subclavian vein to keep the arm veins free for a future fistula.
   • C.It can be used right away, bridging the patient until a permanent access is placed and matures.✓ Answer
   • D.It is better than a fistula long term because it avoids needle sticks at each treatment.

   A catheter is the only access that works the moment it is placed, so it is used when dialysis cannot wait or when peripheral vessels are exhausted, and it is meant to be temporary. Catheters carry the highest infection and mortality risk of any access, and the subclavian site is avoided because central venous stenosis there can ruin future access in that arm.

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

4. 4. How does a tunneled cuffed catheter differ from a non-tunneled temporary catheter?

   • A.The tunneled catheter passes under the skin and its cuff anchors it, so it can stay in longer.✓ Answer
   • B.The tunneled catheter is placed in an arm vein, while the temporary one goes into the neck vein.
   • C.The tunneled catheter is inserted at the bedside and is removed at the end of each treatment.
   • D.The tunneled catheter is used only for urgent dialysis, while the temporary one is for long use.

   The subcutaneous tunnel separates the skin entry point from the vein entry point, and tissue grows into the cuff to seal the tunnel, which slows bacterial migration along the catheter. That is why a tunneled cuffed catheter can remain for weeks to months while a non-tunneled catheter is only for short, urgent use.

   Source: ANNA Core Curriculum for Nephrology Nursing, central venous cathetersReport a problem with this question

5. 5. Which change makes a new arteriovenous fistula ready for cannulation?

   • A.The synthetic wall of the access softens and swelling from the surgery gradually settles down.
   • B.Scar tissue forms around the anastomosis and holds the needle track open for repeated sticks.
   • C.Arterial pressure makes the vein wall thicken and the vessel enlarge, so it tolerates needles.✓ Answer
   • D.The artery narrows above the anastomosis so that blood is forced into the smaller forearm veins.

   Maturation is arterialization: once arterial pressure and flow reach the vein, the vein dilates and its wall thickens until it is large enough, superficial enough and strong enough for repeated needle placement. Cannulating before that happens tears the thin vein wall and can destroy the access, which is why an immature fistula is never used.

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

6. 6. A patient with a new left-arm fistula asks how to protect it at home. Which instruction should the technician reinforce?

   • A.Keep blood pressure cuffs, blood draws and tight sleeves off that arm, and check the thrill daily.✓ Answer
   • B.Keep the arm still and avoid hand exercise, because movement can pull the anastomosis apart.
   • C.Sleep on the fistula arm at night so steady pressure keeps the vein from enlarging too quickly.
   • D.Wrap the arm snugly in an elastic bandage between treatments so that the new fistula stays supported.

   Anything that compresses the access limb slows flow and can let the access clot, so cuffs, tourniquets, venipuncture, tight sleeves and sleeping on the arm are all avoided. Daily thrill checks let the patient detect loss of flow early and call the unit while the access can still be salvaged.

   Source: ANNA Core Curriculum for Nephrology Nursing, patient education for vascular access preservationReport a problem with this question

7. 7. Mr. Alvarez has an upper-arm fistula. Before treatment the technician feels a strong water-hammer pulse instead of the usual soft continuous thrill, hears a high-pitched bruit only during systole, and notes that the whole arm is swollen. What do these findings most likely indicate?

   • A.Infiltration, because blood has leaked out of the vessel into the tissue of the arm.
   • B.Steal syndrome, from too much blood being diverted away from the hand and fingers.
   • C.Outflow stenosis, from narrowing downstream that is backing pressure up in the access.✓ Answer
   • D.Complete thrombosis, because the access has clotted and no blood is moving through it at all.

   A narrowing downstream of the needle zone obstructs outflow, so pressure builds in the access and the soft continuous thrill becomes a hard pulse while the bruit turns high-pitched and systolic only. Swelling of the entire arm fits the same obstruction of venous return, whereas steal produces a cold painful hand and thrombosis abolishes both thrill and bruit.

   Source: ANNA Core Curriculum for Nephrology Nursing, access assessment by look, listen and feelReport a problem with this question

8. 8. After the nurse assesses him, Mr. Alvarez is started on treatment. Thirty minutes in, the venous pressure has climbed steadily at an unchanged blood flow rate and dark streaks are visible in the venous drip chamber. What should the technician do first?

   • A.Give an extra heparin bolus and finish the treatment as scheduled.
   • B.Raise the blood flow rate to push the darkened blood through the venous limb.
   • C.Stop the blood pump, inspect the venous line and needle, and tell the nurse at once.✓ Answer
   • D.Reposition the venous needle and restart the pump at the same setting.

   Rising venous pressure at an unchanged blood flow rate with dark streaking points to clot forming in the venous limb or dialyzer, and continued pumping can push the clot toward the patient or rupture the circuit. The technician stops the pump, looks for clots and kinks, and reports at once; adjusting heparin or the prescribed blood flow rate is outside the technician's scope.

   Source: ANNA Core Curriculum for Nephrology Nursing, intradialytic access monitoring and circuit clottingReport a problem with this question

9. 9. During the pre-treatment check of a forearm graft the technician finds no thrill and hears no bruit, and the graft feels cool and firm. What is the correct action?

   • A.Cannulate carefully with a smaller needle and watch the machine pressures closely during treatment.
   • B.Squeeze the graft firmly along its length to push the clot out before cannulating it.
   • C.Hold cannulation and report the finding to the nurse right away for prompt evaluation.✓ Answer
   • D.Apply a warm pack for several minutes and recheck, then begin if any pulse can be felt.

   Loss of both thrill and bruit in an access that feels cool and cord-like means the access has thrombosed, and cannulating a clotted access damages it and can dislodge clot. Prompt reporting is what allows timely referral for declotting or angioplasty; technicians never attempt to milk, squeeze or flush a clotted access.

   Source: ANNA Core Curriculum for Nephrology Nursing, recognition of access thrombosisReport a problem with this question

10. 10. A patient's graft site is red, warm and tender, and a small amount of yellow drainage is present at an old needle site. Which action should the technician take?

    • A.Clean the drainage away with extra antiseptic and cannulate the usual site as always.
    • B.Report the drainage to the nurse and document the findings before the access is used.✓ Answer
    • C.Cover the drainage with a dressing and cannulate the opposite end of the graft instead.
    • D.Puncture above the reddened area and continue the session, since the drainage is superficial.

    Redness, warmth, tenderness and drainage are signs of access infection, and a needle passed through infected tissue can seed bacteria directly into the bloodstream or into a synthetic graft that cannot clear infection. The technician's role is to withhold use, report to the nurse and document, because assessment, cultures and treatment decisions belong to the nurse and physician.

    Source: CDC Recommendations for Preventing Transmission of Infections Among Chronic Hemodialysis Patients, vascular access infectionReport a problem with this question

11. 11. The technician must identify the direction of blood flow in a forearm loop graft before cannulating. Which method gives that information?

    • A.Briefly occlude the middle of the loop and feel for the pulse on the arterial limb.✓ Answer
    • B.Look at where the surgical scar lies, because flow always runs away from the scarred side.
    • C.Insert a needle into each limb and see which one gives the darker blood in the tubing first.
    • D.Assume flow runs from the thumb side toward the little-finger side in every loop graft.

    Compressing the midpoint of the loop blocks flow, so the limb between the artery and the compressing finger becomes pulsatile while the outflow limb loses its thrill, which identifies the arterial side. Guessing from the scar or from anatomy is unreliable, and using needles to find out risks placing the arterial needle wrong and causing recirculation.

    Source: ANNA Core Curriculum for Nephrology Nursing, cannulation of loop graftsReport a problem with this question

12. 12. Why is the venous (return) needle always directed with the flow of blood, toward the heart, and placed downstream of the arterial needle?

    • A.Because a needle placed downstream can sit closer to the anastomosis safely.
    • B.Because it keeps the return blood from mixing with the heparin in the circuit.
    • C.Because returning blood with the flow, away from the draw site, limits recirculation.✓ Answer
    • D.Because so placed the same needle can also serve as the arterial line.

    Cleaned blood returned downstream and pointed toward the heart is carried away from the draw site, so it is not pulled straight back into the arterial needle. Pointing the venous needle against the flow, or placing it too close to the arterial needle, sends dialyzed blood back into the circuit and lowers the delivered dose.

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

13. 13. The bloodlines are accidentally attached to the wrong needles, so blood is drawn from the needle nearer the heart and returned to the needle nearer the anastomosis. What is the main consequence?

    • A.Blood that was just cleaned is pulled back into the dialyzer, so less urea is removed.✓ Answer
    • B.The venous pressure alarm sounds continuously and the pump cannot reach the set rate.
    • C.The patient receives an unintended blood transfusion from the access into the circuit.
    • D.The dialyzer clots quickly because blood now flows backward through the fiber bundle.

    Reversed lines put the return upstream of the draw, so freshly dialyzed blood is immediately re-aspirated instead of going to the patient, which is recirculation. Nothing alarms and the treatment looks normal, yet the delivered dose falls and this shows up later as an unexplained drop in urea clearance.

    Source: ANNA Core Curriculum for Nephrology Nursing, access recirculationReport a problem with this question

14. 14. A technician has been placing needles in the same two spots for months because they are easy to hit. Why is rope-ladder rotation recommended instead?

    • A.Repeated sticks in one spot make the access wall thicken until needles cannot enter.
    • B.Rotating sites lets the same needle gauge be used no matter how deep the vessel lies.
    • C.Rotating sites removes the need to clean the skin, since each spot is used only once.
    • D.Repeated sticks in one spot weaken the wall, and the weakened segment balloons out.✓ Answer

    Area or one-site puncture destroys the wall in a single small segment, and that weakened segment stretches under access pressure to form an aneurysm in a fistula or a pseudoaneurysm in a graft. Rope-ladder rotation spreads the punctures over the whole cannulation zone so each site can heal before it is used again.

    Source: KDOQI Clinical Practice Guideline for Vascular Access, cannulation site rotationReport a problem with this question

15. 15. Which statement about the buttonhole (constant-site) cannulation technique is correct?

    • A.It allows the scab to be left in place, since the scab seals the track between sessions.
    • B.It uses blunt needles from the first stick, which is what forms the track in the tissue.
    • C.It is the preferred routine method for grafts, because the tough wall holds a track well.
    • D.It is used only in fistulas, and the track must be entered at the same site and angle.✓ Answer

    A buttonhole depends on a healed scar track through tissue, which can only form in a native fistula, so the technique is never used on a synthetic graft. The track is created with sharp needles entering the identical site, angle and depth, blunt needles are used only once it is established, and the scab must be removed and the site disinfected because a retained scab carries bacteria into the tunnel.

    Source: KDOQI Clinical Practice Guideline for Vascular Access, buttonhole cannulationReport a problem with this question

16. 16. How does a pseudoaneurysm in a graft differ from a true aneurysm in a fistula?

    • A.A pseudoaneurysm resolves on its own once the cannulation sites are rotated.
    • B.A pseudoaneurysm is blood pooled outside the graft wall, not a stretched vessel wall.✓ Answer
    • C.A pseudoaneurysm forms only right at the arterial anastomosis of the graft.
    • D.A pseudoaneurysm is a narrowing rather than a bulge, so flow through it falls.

    A true aneurysm is a dilation of a fistula that still involves all layers of the vessel wall, while a pseudoaneurysm is blood that has escaped through repeated puncture holes in a graft and is contained only by surrounding tissue. Both come from puncturing the same spot repeatedly, both are avoided when cannulating, and both must be reported because a rupture is a surgical emergency.

    Source: ANNA Core Curriculum for Nephrology Nursing, aneurysm and pseudoaneurysmReport a problem with this question

17. 17. Shortly after the arterial needle is placed, the patient complains of burning, and the area swells rapidly and begins to darken. What should the technician do first?

    • A.Stop the pump, clamp the line, remove the needle and hold pressure over the site.✓ Answer
    • B.Lower the blood flow rate and keep going, watching whether the swelling gets larger.
    • C.Put a warm pack over the swelling right away and continue the treatment as ordered.
    • D.Push the needle in a little deeper so its tip returns to the middle of the vessel.

    Burning, rapid swelling and discoloration mean the needle tip is outside the lumen and blood is being forced into the tissue, so every second of continued pumping enlarges the infiltration and the resulting hematoma. Stopping the pump, clamping, removing the needle and holding pressure limits the damage; ice is applied in the first day, the nurse is notified, and any recannulation is done away from the injured area.

    Source: ANNA Core Curriculum for Nephrology Nursing, infiltration managementReport a problem with this question

18. 18. After the skin over the fistula has been cleaned with antiseptic and allowed to dry, the technician is unsure exactly where the vessel runs. What is the correct thing to do?

    • A.Feel the vessel with the same glove used to remove the old dressing, then cannulate.
    • B.Feel the vessel with a bare fingertip, since the skin under it was just cleaned.
    • C.Wipe the gloved finger with antiseptic and press on the site until the vein rises.
    • D.Clean the site again after palpating, or palpate only outside the prepared area.✓ Answer

    Skin antisepsis reduces the bacteria at the puncture site, and touching that prepared skin with a finger that is not sterile puts organisms straight back where the needle will carry them into the bloodstream. Either repeat the antisepsis after palpating or keep the palpating finger outside the prepared field; wiping a glove with antiseptic does not make it sterile.

    Source: CDC Recommendations for Preventing Transmission of Infections Among Chronic Hemodialysis Patients, skin antisepsis before cannulationReport a problem with this question

19. 19. What is the correct technique for achieving hemostasis after the needles are removed at the end of treatment?

    • A.Clamp the site tightly enough that no thrill can be felt, and leave the clamp on until discharge.
    • B.Lift the gauze every minute to check the puncture, and press only on the skin opening itself.
    • C.Press down on the skin while the needle is still sliding out, so the site never bleeds.
    • D.Withdraw the needle completely first, then press firmly enough to stop bleeding but keep the thrill.✓ Answer

    Pressing while the needle is still in the vessel drags the bevel against the wall and lacerates it, so the needle comes out completely at the angle it went in before any pressure is applied. Pressure must cover both the skin hole and the deeper vessel hole and must be firm enough to stop bleeding yet light enough that the thrill is still present, because pressure that abolishes the thrill can clot the access.

    Source: ANNA Core Curriculum for Nephrology Nursing, needle removal and hemostasisReport a problem with this question

20. 20. A patient with a new upper-arm fistula says that during treatment the hand on that side becomes cold, pale and numb, and aches. What is the most likely explanation?

    • A.The dialysate is running cooler than the patient's own body temperature during the session.
    • B.Venous outflow is obstructed, so blood is backing up into the hand and fingers.
    • C.Too much arterial blood is diverted into the access, so the hand is short of flow.✓ Answer
    • D.The needles are placed too far apart, which is chilling the tissue between them.

    In steal syndrome the low-resistance access diverts arterial blood away from the distal extremity, so the hand becomes ischemic; the symptoms are typically worst during dialysis when access flow is highest. The technician reports it promptly because untreated ischemia can progress to ulceration or tissue loss and may need surgical flow reduction.

    Source: ANNA Core Curriculum for Nephrology Nursing, dialysis access-related hand ischemiaReport a problem with this question

21. 21. Mrs. Chen dialyzes through a tunneled cuffed catheter. Which practice should the technician follow when connecting and disconnecting the bloodlines?

    • A.Remove the caps early so the lumens can drain any old lock solution before connecting.
    • B.Mask both the patient and staff, and scrub each hub with antiseptic before every access.✓ Answer
    • C.Leave the lumens open to air briefly so trapped air can escape before hookup.
    • D.Flush the heparin lock into the patient so the dose is not wasted at the start.

    An open catheter lumen leads straight into a central vein, so masks on both staff and patient keep respiratory droplets off the connection and hub disinfection removes the biofilm and organisms that would otherwise be pushed inward. A lumen open to air also invites air embolism, and the lock solution is aspirated and discarded rather than flushed into the patient.

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

22. 22. Twenty minutes after Mrs. Chen is connected she has shaking chills and feels feverish, and the technician sees that the exit-site dressing is loose with drainage under it. What should the technician do?

    • A.Slow the blood flow rate and cover the patient with a warm blanket until the chills stop.
    • B.Wipe the exit site with antiseptic, tape the dressing down and finish the session.
    • C.Report the chills and the exit-site drainage to the nurse now, and record the findings.✓ Answer
    • D.Change the dressing, add a warm blanket, and recheck her at the end of treatment.

    Rigors and fever that begin soon after a catheter is accessed, together with exit-site drainage, are classic signs of a catheter-related bloodstream infection, and delay allows the patient to become septic. The technician's job is to report immediately and document; drawing cultures, giving antibiotics and deciding about the catheter are nursing and medical actions.

    Source: CDC Core Interventions for Dialysis Bloodstream Infection Prevention, recognition and reporting of catheter-related bloodstream infectionReport 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) →