22 Instrumentation & Sutures Practice Questions & Answers

1. 1. A vascular clamp is needed to occlude an artery temporarily without injuring the intima. Which jaw design should the scrub technologist pass?

   • A.Jaws with heavy transverse serrations running the full length that lock firmly onto the vessel wall
   • B.Jaws with wide crushing surfaces and a strong ratchet that flatten the vessel before it is ligated
   • C.Jaws with a single interlocking tooth at the tip that anchors the vessel so it cannot slip away
   • D.Jaws with fine, shallow, atraumatic rows of serrations that hold the vessel with light closing pressure✓ Answer

   An atraumatic vascular clamp holds with fine, shallow serrations and light spring pressure, so the wall is occluded without crushing it or shearing the intimal lining; a damaged intima is where thrombus forms after the clamp comes off. Toothed, heavy-serrated, or crushing jaws are designed for tough tissue that will be excised or ligated, not for a vessel that must stay patent.

   Source: NBSTSA CST Exam Content Outline, identify instruments by function, application, classification; AST Standards of Practice; Nemitz, Surgical Instrumentation - occluding/clamping instrumentsReport a problem with this question

2. 2. The surgeon needs a grasper to hold a loop of small bowel while the serosa is inspected. Which jaw design is appropriate?

   • A.Broad, smooth, fenestrated jaws that cradle the loop and spread the pressure over a wide area✓ Answer
   • B.Delicate cross-serrated tips on a spring handle that pinch a small fold of tissue very precisely
   • C.Fine transverse serrations ending in a one-by-two tooth tip that anchors dense and tough tissue
   • D.Short interlocking teeth at the jaw tips that bite the wall so the loop cannot slide during traction

   Hollow viscus is grasped with broad, smooth, fenestrated jaws because the load is spread over a large surface and no tooth perforates the wall. Interlocking or one-by-two teeth concentrate force at a point and are reserved for fascia and other tough tissue that will be removed or closed under tension.

   Source: NBSTSA CST Exam Content Outline; Alexander's Care of the Patient in Surgery - grasping and holding instrumentsReport a problem with this question

3. 3. The surgeon is dissecting a thin, delicate tissue plane and asks for scissors. Which pair should be passed?

   • A.Scissors with short, heavy, beveled blades built to cut dense fascia and tough connective tissue
   • B.Scissors with straight blades and one serrated edge kept on the field only for cutting suture
   • C.Scissors with angled, sharp-pointed blades made to slip under a stitch and lift it for removal
   • D.Scissors with long shanks and short, fine, blunt-tipped curved blades meant for delicate dissection✓ Answer

   Delicate dissecting scissors have long shanks with short, fine blades, which puts the cutting surface deep in the wound while keeping the bite small and controlled. Heavy short-bladed scissors are for dense tissue and for suture; using dissecting scissors on suture dulls them and ruins the fine tips.

   Source: NBSTSA CST Exam Content Outline; Nemitz, Surgical Instrumentation - cutting and dissecting instrumentsReport a problem with this question

4. 4. A deep abdominal wound must stay exposed through a long dissection and no extra assistant is available. Which retractor choice best meets that need?

   • A.A self-retaining retractor whose ratcheted arms hold the blades apart without a hand on them✓ Answer
   • B.A malleable ribbon bent to shape and held down by the weight of the packing above it
   • C.A handheld double-ended retractor held steady by the scrub technologist for the whole case
   • D.A shallow rake retractor placed at the wound edge and moved each time the plane deepens

   A self-retaining retractor locks its own arms open on a ratchet, so exposure is maintained for long periods without a hand committed to it, which is exactly the problem when no assistant is free. Handheld retractors give fine, adjustable control but tie up a person and drift as the hand tires.

   Source: NBSTSA CST Exam Content Outline, assemble and maintain retractors; AST Standards of PracticeReport a problem with this question

5. 5. A large volume of free fluid must be cleared quickly from the open abdomen. Which suction tip should be ready on the field?

   • A.A fine single-lumen tip with a thumb port used for small amounts in a shallow surface wound
   • B.A slender angled tip with a fingertip valve used to keep a microsurgical field dry and clear
   • C.A short blunt tip with side holes used to clear secretions from the mouth and the oropharynx
   • D.A large-bore rigid tip with a guard that keeps omentum and bowel from being pulled into it✓ Answer

   High-volume evacuation needs a wide bore so flow is not the limiting factor, and a guard or shield so viscera and omentum are not sucked into the lumen and injured. Fine-tipped and angled tips are built for precision in shallow or microsurgical fields and clog almost at once in a pool of blood.

   Source: NBSTSA CST Exam Content Outline, probing, dilating, suctioning instruments; Alexander's Care of the Patient in SurgeryReport a problem with this question

6. 6. How should a curved hemostat be placed in the surgeon's hand so it can be used at once without the surgeon looking away from the field?

   • A.Laid on the sterile field within easy reach so the surgeon may pick it up without breaking focus
   • B.Snapped firmly into the open palm, ring handles first, with the tip curved the way it will be used✓ Answer
   • C.Given with the ratchet fully locked so the jaws stay firmly shut until the surgeon opens them
   • D.Handed over tip first so the surgeon can see the jaws clearly and take hold of the working end fast

   An instrument is passed handle first with a firm, decisive placement into the palm, oriented so the curve of the tip already points the direction of use; the surgeon feels it seat and works without looking up. Passing tip first exposes the working end to the technologist's hand and forces the surgeon to reorient it.

   Source: NBSTSA CST Exam Content Outline, pass instruments and supplies; AST Standards of PracticeReport a problem with this question

7. 7. What is the safest way to transfer a loaded needle holder or a scalpel between the technologist and the surgeon?

   • A.Left on the Mayo stand with a verbal cue so the surgeon retrieves it when the hands are free
   • B.Passed hand to hand while announcing the word sharp so both people know a blade is moving
   • C.Handed straight to the surgeon with the sharp turned away, since a direct pass is faster and controlled
   • D.Placed in an agreed neutral zone, such as a basin or magnetic pad, so one hand holds it at a time✓ Answer

   Hands-free transfer through a designated neutral zone means the sharp is never held by two people at the same moment, which removes the exact instant in which most operating-room needlesticks happen. Announcing a direct hand-to-hand pass is better than silence, but two hands are still on the sharp at once.

   Source: NBSTSA CST Exam Content Outline; AST Standards of Practice - sharps handling and neutral zone techniqueReport a problem with this question

8. 8. A swaged suture needle is being loaded onto a needle holder. Where should the jaws grasp it?

   • A.About one third to one half back from the swage, with the needle at a right angle to the jaws✓ Answer
   • B.At the very tail of the curve, so the whole length of the needle is free for a deep tissue bite
   • C.Behind the point, so the sharp end is short and the surgeon can start the stitch immediately
   • D.Right on the swage itself, so the strand stays in line and the needle cannot turn in the jaws

   Clamping one third to one half back from the swage puts the jaws on the strongest part of the body, leaves enough curve ahead to complete the bite, and keeps the swage, the weakest point, out of the crush. Clamping on the swage can bend or detach the needle from the strand.

   Source: NBSTSA CST Exam Content Outline, prepare, pass, and cut suture as directed; Alexander's Care of the Patient in Surgery - needle handlingReport a problem with this question

9. 9. During the case, how should instruments on the sterile field be kept clean and working?

   • A.Wiped with a sponge moistened with normal saline and returned to the Mayo stand right away
   • B.Left with blood in place so the ultrasonic cleaner removes the dried film in decontamination
   • C.Wiped with a dry sponge only, because any moisture on the jaws makes the ratchets slip and release
   • D.Wiped with a sponge moistened with sterile water, and lumens flushed as blood collects in them✓ Answer

   Blood is wiped off with sterile water because dried blood cements box locks and serrations and blocks lumens, and because saline is corrosive to stainless steel and pits the surface with repeated exposure. Flushing lumens on the field keeps suction tips and cannulas patent for the rest of the case.

   Source: NBSTSA CST Exam Content Outline, decontaminate and clean instruments; pre-clean at point of use; AST Standards of PracticeReport a problem with this question

10. 10. The case has ended and the instrument set is being readied for transport to decontamination. Which handling is correct?

    • A.Ratchets locked and heavy clamps stacked on top so the delicate tips underneath are protected
    • B.Box locks and ratchets opened, the instruments kept moist, and the set moved in a closed container✓ Answer
    • C.The set left to air dry on the back table and sent uncovered on the case cart to the workroom
    • D.The whole set submerged in saline in an open basin so dried blood loosens before washing

    Instruments go to decontamination open, so cleaning solution reaches box locks and serrations, and moist, so blood and protein do not dry into a film that resists cleaning; the container is closed and leak-proof so contaminated items are contained in transit. Saline soaking corrodes and pits stainless steel.

    Source: NBSTSA CST Exam Content Outline, prepare instruments for transport to decontamination; AST Standards of PracticeReport a problem with this question

11. 11. The surgeon is using 2-0 suture and asks for a finer strand. Which size is finer, and why?

    • A.1, because sizes are ranked by tensile strength and the lowest number is always the finest gauge
    • B.5-0, because each added zero on the USP scale means a smaller diameter and less tensile strength✓ Answer
    • C.2, because the plain numbers on the USP scale mark the finer strands and the zeros the heavy ones
    • D.0, because the scale climbs from the zeros to 5 and any single digit is finer than a zero size

    On the USP scale the sizes run 5, 4, 3, 2, 1, 0, 2-0, 3-0 and downward, so every additional zero is a thinner strand carrying less tensile strength; 5-0 is therefore finer than 2-0. The working rule is to choose the smallest size that will still hold the tissue being approximated.

    Source: USP suture size classification; NBSTSA CST Exam Content Outline, identify appropriate usage of sutures and needlesReport a problem with this question

12. 12. A grossly contaminated wound still needs its fascia closed. Which property makes a monofilament strand the better choice?

    • A.It absorbs faster than a braided strand, so the foreign body is gone before infection takes hold
    • B.It has a rougher surface than a braided strand, so it grips tissue and resists loosening later
    • C.It has no braided interstices, so fluid and bacteria are not drawn along it by capillary action✓ Answer
    • D.It handles more softly than a braided strand, so a secure knot needs far fewer throws to hold

    A braided strand has spaces between the filaments that wick fluid and carry organisms along the suture line, a property called capillarity; a single smooth filament has no such spaces, so it is preferred where contamination is present. Braided material handles and knots better, which is why it is chosen in clean wounds.

    Source: NBSTSA CST Exam Content Outline; AST Standards of Practice; suture material classification (monofilament vs multifilament capillarity)Report a problem with this question

13. 13. A large deep vessel is clamped and the surgeon wants a ligature that cannot slip off the stump. What should be prepared?

    • A.A suture ligature swaged onto a needle, passed through the vessel wall and then tied around it✓ Answer
    • B.A tie loaded on a long passer so the strand is carried down and dropped over the clamp tip
    • C.A continuous strand on a reel that is drawn off as needed and tied over the tip of the clamp
    • D.A free tie cut to length and handed as a single strand to be looped around the clamped stump

    A suture ligature, or stick tie, is a strand on a needle that is passed through the wall of the vessel before it is tied, so the ligature is anchored in the tissue and cannot roll off a large pulsating stump. A plain free tie only encircles the stump and can slip once the clamp is released.

    Source: NBSTSA CST Exam Content Outline, mechanical hemostasis; Alexander's Care of the Patient in Surgery - ligatures and suture ligaturesReport a problem with this question

14. 14. The surgeon is closing an enterotomy in the small bowel. Which needle point is correct, and why?

    • A.A conventional cutting point, whose inner edge opens a clean channel through the bowel wall
    • B.A blunt point, which pushes through without cutting and suits dense scarred bowel wall
    • C.A taper point, which spreads the tissue apart as it passes and leaves the smallest hole behind✓ Answer
    • D.A reverse cutting point, whose outer edge keeps tough tissue from tearing along the stitch

    Bowel, peritoneum, and vessel are easily penetrated tissues, so a round-bodied taper point is used: it separates fibers rather than cutting them and leaves a hole no larger than the strand, which limits leakage and bleeding. A cutting edge would slice the wall and enlarge the tract around the suture.

    Source: NBSTSA CST Exam Content Outline; surgical needle point geometry (taper vs cutting)Report a problem with this question

15. 15. Where does the third cutting edge sit on a reverse cutting needle, and what does that placement achieve?

    • A.On the flat of the body, which widens the channel evenly so the strand follows with less drag
    • B.On the outer convex curve, which puts the cut away from the wound edge and resists cut-through✓ Answer
    • C.At the tip alone, which keeps all cutting at the point and spares the tissue behind the tip
    • D.On the inner concave curve, which aims the cut toward the wound edge and eases entry into the skin

    A reverse cutting needle carries its third edge on the outside of the curve, so the cut surface faces away from the wound edge and a bridge of uncut tissue remains between the suture and the edge. That bridge is what keeps the stitch from tearing out through skin and other tough tissue.

    Source: NBSTSA CST Exam Content Outline; surgical needle point geometry (reverse cutting vs conventional cutting)Report a problem with this question

16. 16. Sutures must be placed in friable liver parenchyma. Which needle point suits that tissue, and why?

    • A.A cutting point, which parts the capsule cleanly so the needle never drags on friable tissue
    • B.A taper-cut point, which joins a sharp cutting tip to a round body for tough fibrotic tissue
    • C.A blunt point, which separates soft tissue instead of cutting it and tears the parenchyma less✓ Answer
    • D.A spatula point, which travels within a flat plane and is used where tissue layers are very thin

    Blunt-point needles push soft parenchyma aside instead of slicing it, so friable organs such as liver and kidney hold the stitch instead of tearing along the needle track; the same design also lowers the risk of a needlestick to the team. Cutting edges lengthen the tract and increase bleeding in soft organs.

    Source: NBSTSA CST Exam Content Outline; surgical needle point geometry (blunt point for friable parenchyma)Report a problem with this question

17. 17. What does a linear cutting stapler do to the tissue when it is fired?

    • A.It sets down two double staggered staple lines and divides the tissue between them in one pass✓ Answer
    • B.It sets down a single straight staple line and leaves the tissue intact for the surgeon to divide
    • C.It places a single metal clip on a vessel and must be reloaded by hand before the next firing
    • D.It joins two lumens end to end and releases a ring of tissue that is sent off as a specimen

    A linear cutting device fires staggered rows of staples on each side of its line and runs a knife between them in the same action, so both cut edges are already closed and hemostatic. A non-cutting linear device only closes the tissue, and a circular device makes an anastomosis and delivers tissue rings.

    Source: NBSTSA CST Exam Content Outline, assist with stapling devices; Alexander's Care of the Patient in Surgery - surgical staplingReport a problem with this question

18. 18. A bleeding cut sternal edge is sealed with bone wax. Which category of hemostasis does that action belong to?

    • A.Chemical, because the wax reacts with plasma proteins at the bone edge to speed clot formation
    • B.Mechanical, because the wax physically blocks the open vascular channels in the cut bone surface✓ Answer
    • C.Pharmacologic, because the wax releases an agent that constricts small vessels in the marrow
    • D.Thermal, because the wax softens in the hand and seals the surface as it cools and hardens

    Bone wax works purely by tamponade: it is pressed into the bleeding cancellous surface and physically plugs the vascular channels, with no chemical or clotting action at all. Mechanical hemostasis also covers clamps, ligatures, clips, pressure, and packing, while thermal covers energy devices.

    Source: NBSTSA CST Exam Content Outline, differentiate mechanical, thermal, and chemical hemostasis; AST Standards of PracticeReport a problem with this question

19. 19. Why does bipolar electrosurgery not require a patient return electrode?

    • A.Current is converted into heat inside the handpiece itself, so no electrical energy reaches tissue
    • B.Current is delivered at so low a voltage that no return path is needed to complete the circuit
    • C.Current returns only through a shielded second wire inside the instrument cord, not the skin
    • D.Current passes only between the two tips of the forceps, so the circuit closes at the instrument✓ Answer

    In a bipolar circuit the two poles are the two tips of the forceps, so current travels through the small piece of tissue held between them and returns through the instrument; the patient is never part of a long current path. Monopolar current must cross the body to a dispersive return electrode.

    Source: AST Standards of Practice for Use of Electrosurgery; NBSTSA CST Exam Content Outline, thermal hemostasisReport a problem with this question

20. 20. During laparoscopy a loop of bowel is burned by an active monopolar electrode that never touched it; the insulation is later found intact and the tip touched no other instrument. Which mechanism explains the injury?

    • A.Capacitive coupling, in which current passes through intact insulation into a nearby conductor✓ Answer
    • B.Direct coupling, in which the activated tip touches another metal instrument inside the abdomen
    • C.Insulation failure, in which a crack in the shaft lets current escape at a point out of the view
    • D.Residual heat, in which a hot tip laid on tissue burns it after the generator has been released

    Capacitance forms whenever an active electrode runs inside another conductor, such as a metal cannula or the working channel of a scope, and energy can then transfer across intact insulation to that conductor and discharge into tissue out of view. That is why the injury occurs with no break in the insulation and no contact.

    Source: AST Standards of Practice for Use of Electrosurgery - laparoscopic stray current (insulation failure, direct coupling, capacitive coupling)Report a problem with this question

21. 21. Why is a lighted fiberoptic cable never left lying on the drapes after it is disconnected from the scope?

    • A.The free end can carry stray electrical current from the light source into the damp drape
    • B.The free end concentrates intense light into heat that can scorch the drape it is resting on✓ Answer
    • C.The free end pulls lint off the drape into the fibers and clouds the image on the monitor
    • D.The free end loses light output whenever the fibers lie flat on an absorbent surface

    A high-intensity light source delivers enough radiant energy at the end of the cable that the beam behaves as a heat source; resting it on cloth can char or ignite the material within seconds. The cable is kept connected to the scope or the source is turned to standby, and the cable is never sharply kinked.

    Source: NBSTSA CST Exam Content Outline, assemble, test, and operate specialty equipment - endoscopic; AST Standards of PracticeReport a problem with this question

22. 22. A power drill is being used on bone. What is the scrub technologist's responsibility while it runs and when it is handed back?

    • A.Irrigate the site steadily during drilling and set the safety lock before every handoff✓ Answer
    • B.Wipe the bur dry between passes and hand the drill back running so no operating time is lost
    • C.Hold suction at the bur and leave the trigger free so the surgeon can restart without delay
    • D.Keep the cord pulled taut toward the source and change the bur while the handpiece is powered

    Continuous irrigation carries away the heat generated by the bur or blade, and bone that is allowed to overheat undergoes thermal necrosis at the implant site. The safety lock is engaged whenever the handpiece is passed or a bur is changed, so an accidental trigger pull cannot injure a hand.

    Source: NBSTSA CST Exam Content Outline, assemble, test, operate, and disassemble specialty equipment - powered instruments; AST Standards of PracticeReport a problem with this question

Practice questions based on the NBSTSA Certified Surgical Technologist exam content outline, AST standards of practice, and durable operating-room principles. CST is a mark of the National Board of Surgical Technology and Surgical Assisting; this site is not affiliated with or endorsed by NBSTSA or AST. Surgical counts, documentation, and what a technologist may perform are governed by your facility's policy and by state law, and sterilization parameters follow the manufacturer's written instructions — confirm all of these locally rather than from a practice test, and confirm current eligibility and exam requirements with the certifying board. About the CST exam →