20 free CST practice questions

Correct answer: A · Set it aside as nonsterile, open another set, and send it for reprocessing

CDC's Guideline for Disinfection and Sterilization in Healthcare Facilities (2008) says packaged sterile items can be used indefinitely under event-related storage unless the packaging is compromised, that packages should be checked for loss of integrity such as tears, wetness, or punctures before use, and that a compromised package must be repacked and reprocessed before use. A tear and a damp spot are exactly that kind of event, so the set is no longer considered sterile. Event-related sterility depends on the package staying intact; a recent date does not cancel damage. Instruments that look dry may still have been exposed through the wet, torn wrap. Tape does not restore sterility. The CST outline lists checking packages for sterile integrity under Preoperative Preparation.

Look for this next time: A torn or wet sterile package is contaminated whatever its date; set it aside and send it for reprocessing.

Correct answer: D · The accountable licensed practitioner, or a permitted delegate, marks it

The Joint Commission's 2026 National Performance Goal NPG.01.06.02 says the site is marked before the procedure, with the patient involved if possible, by a licensed practitioner who is ultimately accountable for the procedure and will be present. Delegation is limited to a supervised physician in postgraduate training, or an advanced practice registered nurse or physician assistant working with the surgeon, who is familiar with the patient and will be present. A surgical technologist or circulator is not on that list, even with a consent that names the side. The goal also says the mark must stay visible after skin prep and draping, and that adhesive markers are not the sole means of marking. The CST's role is to speak up if the site is unmarked before the time-out.

Look for this next time: Site marking belongs to the accountable licensed practitioner or a narrow set of delegates, not the CST or circulator.

Correct answer: B · Just before the incision, with the surgeon, anesthesia, circulator, and CST

NPG.01.06.03 in The Joint Commission's 2026 hospital goals says the time-out is conducted immediately before starting the invasive procedure or making the incision. It is standardized, initiated by a designated team member, and involves the immediate procedure team: the person performing the procedure, the anesthesia providers, the circulating nurse, the operating room technician, and others active from the beginning. At a minimum, the team agrees on the correct patient identity, correct site, and procedure to be done, and the completion is documented. A preop conversation is part of verification, not the time-out. A time-out after trocar placement comes after the first incisions. A desk check excludes the team and happens too early. The CST outline lists participating in the time-out under Preoperative Preparation.

Look for this next time: The time-out happens immediately before the incision and includes the whole immediate team agreeing on patient, site, and procedure.

Correct answer: C · Label both the cup and the syringe with name, strength, and other details

NPG.14.03.01 in The Joint Commission's 2026 hospital goals requires labeling all medications, medication containers, and other solutions on and off the sterile field, and notes that containers include syringes, medicine cups, and basins. Labeling applies to anything not immediately administered, even if only one medication is in use, and it happens when the medication leaves its original packaging. The label includes the medication name, strength, amount if not apparent, diluent if any, and expiration date and time, which the hospital may omit for short procedures. Labeling only the syringe leaves an unlabeled cup of clear fluid on the field. Holding the syringe is not immediate administration if minutes will pass. A vial on another table is not a label on the container.

Look for this next time: Label every cup, syringe, and basin on the field as soon as a medication is transferred into it, even if it is the only one.

Correct answer: A · Read back the name and strength with the circulator, aloud and visually

The heparin sodium injection label carries a Fatal Medication Errors warning: confirm the correct strength before administration, because the strengths include a highly concentrated 10,000 units in 1 mL, and fatal hemorrhages have occurred when such vials were confused with catheter lock flush products. NPG.14.03.01 in The Joint Commission's 2026 hospital goals adds that medication and solution labels are verified both verbally and visually, by two qualified people, whenever the person preparing the medication is not the person who will administer it. The CST and circulator therefore read back the drug and strength together, and the resulting solution is labeled. Trusting the selection skips the check. The expiration date matters but says nothing about strength. Cap color is not a reliable way to identify strength.

Look for this next time: Verify every medication passed to the field aloud and visually with the circulator; heparin strength errors have been fatal.

Correct answer: B · It is for the surface of bleeding tissue only and must never be injected

The label for bovine topical thrombin (Thrombin-JMI) states that it is for topical use on the surface of bleeding tissue only and must not be injected, and warns that injection into the circulatory system can cause extensive intravascular clotting or death. A syringe may be used to flood the bleeding surface, but never to inject into a vessel. Adding it to IV fluids is a form of systemic injection. The label's boxed warning describes severe bleeding and thrombosis complications linked to antibodies against bovine thrombin and factor V, so 'safe in any amount' is false. The CST outline lists preparing hemostatic agents and verifying, receiving, mixing, and labeling medications under Intraoperative Procedures.

Look for this next time: Topical thrombin goes only on the surface of bleeding tissue; never inject it into a vessel or IV line.

Correct answer: D · Recap only with a one-handed technique or device, or discard it

OSHA's Bloodborne Pathogens Standard, 29 CFR 1910.1030(d)(2)(vii), prohibits bending, recapping, or removing contaminated needles unless no alternative is feasible or a specific procedure requires it, and then the recapping or removal must be done with a mechanical device or a one-handed technique. Shearing or breaking contaminated needles is prohibited outright. If the plan is to reuse this needle on the same patient, recapping with a one-handed scoop or a recapping device on the back table meets the rule; otherwise the needle is discarded into a sharps container and a new one is used at closing. Two-handed recapping is the classic way scrub personnel stick themselves. Removing it by hand and leaving it loose violates the rule. Bending is prohibited.

Look for this next time: Never recap with two hands or bend a used needle; recap only one-handed or with a device when reuse is required.

Correct answer: C · Goggles or glasses with solid side shields, or a chin-length face shield

OSHA's Bloodborne Pathogens Standard, 29 CFR 1910.1030(d)(3)(x), requires masks in combination with eye protection devices, such as goggles or glasses with solid side shields, or chin-length face shields, whenever splashes, spray, spatter, or droplets of blood or other potentially infectious materials may be generated and eye, nose, or mouth contamination can reasonably be anticipated. Pulsed lavage in a joint replacement is a clear splash situation. Everyday glasses without solid side shields do not meet that description. A gown and gloves protect skin and clothing, not the eyes. Double gloving helps with glove perforation but is not eye protection. Shoe covers do not protect mucous membranes.

Look for this next time: When splashes are expected, wear a mask plus goggles, side-shielded glasses, or a chin-length face shield.

Correct answer: A · Once relieved, wash the site with soap and water and report it at once

CDC's NIOSH guidance says to wash needlestick punctures with soap and water, report the incident to a supervisor, and seek medical care immediately to determine the risk. The 2001 U.S. Public Health Service exposure guidelines add that there is no evidence squeezing the wound reduces risk and that caustic agents such as bleach are not recommended. With a relief CST available, she can leave the field safely, wash, and report so the source patient and she can be evaluated promptly. Finishing the case and waiting until the end of the day delays that evaluation. Unknown status is a reason to report, not to ignore the exposure. The CST outline lists following Standard and Universal Precautions under Intraoperative Procedures.

Look for this next time: After a sharps injury, get relieved, wash with soap and water, and report it immediately for post-exposure evaluation.

Correct answer: B · Label the container in the room, in the patient's presence, with two identifiers

NPG.01.01.01 in The Joint Commission's 2026 hospital goals requires at least two patient identifiers, says the patient's room number or physical location is not an identifier, and requires containers used for blood and other specimens to be labeled in the presence of the patient. Labeling in the room, before the specimen leaves, matches the container to the right patient while that patient is still present; the CST also confirms the specimen name and side with the surgeon. Batch labeling at the end of the day is how specimens get switched. A room number is a location, not an identifier. An unlabeled container sent to pathology may not be matched to the right patient. The CST outline lists verifying, preparing, and labeling specimens under Intraoperative Procedures.

Look for this next time: Label specimen containers in the OR, in the patient's presence, using at least two patient identifiers.

Correct answer: C · Bring the MH cart and help prepare dantrolene for rapid IV use

The Malignant Hyperthermia Association of the United States (MHAUS) crisis guidance tells the team to get dantrolene and the MH cart, hyperventilate with 100% oxygen at high flows to flush volatile anesthetics and lower end-tidal CO2, and give IV dantrolene rapidly, repeating as needed. If surgery must continue, anesthesia is maintained with non-triggering IV agents, which MHAUS lists as including non-depolarizing neuromuscular blockers; succinylcholine, a depolarizing relaxant, is a known trigger and would worsen the crisis. Increasing sevoflurane adds more of the triggering agent. Active warming adds heat to a hypermetabolic crisis. The CST outline lists anesthesia complications such as malignant hyperthermia under Surgical Pharmacology and performing appropriate actions during an emergency under Intraoperative Procedures.

Look for this next time: In suspected malignant hyperthermia, get the MH cart and dantrolene while the triggers are stopped.

Correct answer: D · A new time-out before the reconstruction begins

NPG.01.06.03 in The Joint Commission's 2026 hospital goals says that when two or more procedures are performed on the same patient and the person performing the procedure changes, a time-out is performed before each procedure is initiated. Here the procedure and the surgeon both change, so the team pauses again before reconstruction starts and agrees, at a minimum, on the correct patient, site, and procedure, then documents it. The first time-out covered the first surgeon's procedure only. A note that the surgeon arrived is not a time-out. A surgeon reading the consent alone leaves out the immediate team, which the time-out must involve. The CST outline lists participating in Universal Protocol (Time Out).

Look for this next time: When a different person starts a second procedure on the same patient, the team performs a new time-out first.

Correct answer: A · Close the full container, replace it, and discard the sharps in a new one

OSHA's Bloodborne Pathogens Standard, 29 CFR 1910.1030(d)(4)(iii)(A), requires contaminated sharps to be discarded immediately or as soon as feasible in containers that are closable, puncture resistant, leakproof on the sides and bottom, and labeled; during use, containers must be replaced routinely and not allowed to overfill; and they must be closed immediately before removal or replacement. So the CST closes the full container, gets a new one, and discards the remaining sharps into it. Forcing sharps into a full container is how hands get stuck and containers spill. A biohazard bag is not puncture resistant. Leaving sharps exposed passes the hazard to someone else. The CST outline lists disposing of contaminated sharps after surgery under Postoperative Procedures.

Look for this next time: Never overfill a sharps container; close it, replace it, and put remaining sharps in the new container.

Correct answer: B · The product's Safety Data Sheet (SDS)

OSHA's Hazard Communication Standard, 29 CFR 1910.1200(g), requires a Safety Data Sheet for each hazardous chemical, organized in set sections that include Section 4, first-aid measures, and Section 6, accidental release measures. Employers must keep SDSs readily accessible and train employees on how to protect themselves in the event of a spill or leak. Formalin is a formaldehyde solution, so the team uses the SDS for the coworker's skin exposure and for cleanup, along with the department's spill procedure. The container label identifies the product and its dates but not the full response steps. Preference cards and count sheets have nothing to do with chemical hazards. The CST outline lists recognizing safety and environmental hazards, such as chemical spills, under Administrative and Personnel.

Look for this next time: For a chemical splash or spill, go to the Safety Data Sheet: Section 4 is first aid and Section 6 is spill response.

Correct answer: D · Get the sterile replacement plate instead of flashing the implant

CDC's Guideline for Disinfection and Sterilization in Healthcare Facilities (2008) recommends not flash sterilizing implanted surgical devices unless doing so is unavoidable. Here it is avoidable: a sterile replacement is 15 minutes away, and the patient is stable, so the team waits for it and the dropped plate goes back for full reprocessing. An implant stays in the patient, so a sterilization failure can cause a deep, hard-to-treat infection. An alcohol wipe and an antiseptic soak are not sterilization at all. The CST outline lists equipment decontamination and sterilization under Equipment Sterilization and Maintenance.

Look for this next time: Avoid flash sterilizing implants; when a sterile replacement can be obtained, use it.

Correct answer: C · Remove gross soil and keep the instruments from drying until cleaning

CDC's Guideline for Disinfection and Sterilization in Healthcare Facilities (2008) says to clean medical devices as soon as practical after use, for example at the point of use, because dried soil is harder to remove and makes disinfection or sterilization less effective, and to clean items meticulously with water and detergent before sterilization. When cleaning must wait, the point-of-use step that follows from this is removing gross soil and keeping the instruments from drying, by the method the facility's procedure sets, until decontamination can clean them. Letting soil dry works against cleaning. Steam sterilization cannot be relied on when bioburden and dried tissue shield organisms, which is why cleaning comes first. A dry wipe and a return to the shelf skips decontamination and sterilization entirely. The CST outline lists pre-cleaning, decontaminating, and cleaning instruments under Equipment Sterilization and Maintenance.

Look for this next time: Clean instruments as soon as practical and keep soil from drying; sterilization only works on items that are clean first.

Correct answer: A · The left atrium and the left ventricle

NHLBI's description of the heart's valves says the tricuspid valve separates the right atrium and right ventricle, the mitral valve separates the left atrium and left ventricle, the pulmonary valve separates the right ventricle and the pulmonary artery, and the aortic valve separates the left ventricle and the aorta. So the mitral valve lies between the left atrium and left ventricle, where it keeps blood from flowing back into the atrium when the ventricle contracts. The other three options describe the tricuspid, aortic, and pulmonary valves. Knowing which chamber lies on each side of a valve helps the CST anticipate the approach and the instruments for valve surgery. The CST outline lists cardiovascular anatomy under Anatomy and Physiology.

Look for this next time: Mitral: left atrium to left ventricle. Tricuspid: right side. Aortic and pulmonary valves sit at the ventricles' outflow.

Correct answer: B · The pulmonary artery

NHLBI explains that the pulmonary artery carries oxygen-poor blood from the heart to the lungs, where oxygen is added, and that the oxygen-rich blood returns to the heart through the pulmonary veins. The pulmonary valve separates the right ventricle from the pulmonary artery. That makes the pulmonary artery the vessel an embolectomy clears when a large clot blocks blood flow to the lungs. The pulmonary veins return oxygen-rich blood to the left atrium. The ascending aorta carries oxygen-rich blood from the left ventricle to the body. The superior vena cava returns oxygen-poor blood from the upper body to the right atrium. The CST outline lists the cardiovascular and pulmonary systems under Anatomy and Physiology.

Look for this next time: The pulmonary artery carries oxygen-poor blood from the right ventricle to the lungs; the pulmonary veins bring it back oxygenated.

Correct answer: C · Geobacillus stearothermophilus, whose spores are highly resistant to steam

CDC's Guideline for Disinfection and Sterilization in Healthcare Facilities (2008) recommends testing sterilizers with biological indicators at least weekly, using commercial spore preparations matched to the sterilization method; for steam, the example is Geobacillus stearothermophilus. Bacterial spores are among the most resistant forms of microbial life, so if a cycle kills a large population of these spores, it can be relied on to kill the less resistant organisms on instruments. Staphylococcus aureus is an important cause of surgical site infections, but as a vegetative bacterium it is far easier to kill and would not challenge the cycle. Escherichia coli is also a vegetative bacterium. Clostridioides difficile matters for environmental cleaning, not as a steam test organism. The CST outline lists the classification of microorganisms and infection control under Microbiology.

Look for this next time: Steam biological indicators use highly resistant Geobacillus stearothermophilus spores; killing them shows the cycle works.

Correct answer: D · 42 mL

A 1% solution contains 1 g per 100 mL, which is 10 mg per mL; the lidocaine with epinephrine label also lists the 1% product as 10 mg/mL. Step by step: maximum dose = 7 mg/kg × 60 kg = 420 mg, which is under the 500 mg general ceiling; volume = 420 mg ÷ 10 mg/mL = 42 mL. A volume of 27 mL comes from the label's lower limit of 4.5 mg/kg (270 mg), which applies to lidocaine without epinephrine. A volume of 50 mL applies the 500 mg ceiling without considering weight. A volume of 4.2 mL treats 1% as 100 mg/mL. The label adds that the dose must be individualized and the smallest effective dose used. The CST outline lists awareness of maximum dosages, such as lidocaine, and weights, measures, and conversions under Surgical Pharmacology.

Look for this next time: A 1% solution is 10 mg/mL; lidocaine with epinephrine tops out at 7 mg/kg, or 42 mL of 1% for a 60 kg adult.