The CST (Certified Surgical Technologist) is an allied-health certification awarded by NBSTSA.
NBSTSA publishes the official exam outline, eligibility rules and fees — see NBSTSA's official page before you book.
Twenty CST (Certified Surgical Technologist) questions, with the answers hidden until you want them — covering Procedures, Equipment, Safety, Pharmacology and more. They are real cards from our 1040-card deck, not the 30 on the free preview page, so you can use both. Work through them cold, then use your score below to decide what to study next. NBSTSA publishes the official exam outline — check it for the real blueprint.
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What is the correct anatomical sequence for a timed surgical hand scrub starting from the fingertips?
Show answer →1. Fingertips 2. Fingers (four planes) 3. Palm/back of hand 4. Wrist 5. Forearm to 2 inches above the elbow. Rationale: Scrubbing from cleanest to dirtiest areas prevents recontamination of the hands. NBSTSA Tip: Watch for distractors suggesting the elbow is scrubbed first or that the upper arm/shoulder is included in the standard scrub.
Before applying a waterless, alcohol-based surgical hand rub (ABHR), what prerequisite step is mandatory for the first case of the day?
Show answer →A traditional 1-minute pre-wash with non-antimicrobial soap and water, followed by subungual cleaning with a disposable nail pick. Rationale: ABHRs are effective against microbes but do not remove gross soil. Hands must be completely dry before ABHR application to prevent dilution and skin irritation. NBSTSA Tip: The exam often focuses on the completely dry requirement for ABHR efficacy.
Why are artificial nails and nail polish strictly prohibited for the surgical technologist according to AST and AORN standards?
Show answer →Artificial nails harbor subungual fungi and bacteria (e.g., Pseudomonas); polish can crack and harbor microbes. Rationale: Fingernails must be <1/4 inch to prevent glove punctures and allow effective cleaning. NBSTSA Tip: Focus on the harboring of microorganisms and risk of fungal growth as the primary reasons, rather than just the risk of polish falling into the wound.
During a 5-minute timed scrub, the ST's elbow accidentally touches the non-sterile faucet at the 4-minute mark. What is the required corrective action?
Show answer →The scrub must be restarted for that specific arm/area, or the entire scrub reset depending on facility policy, to ensure the full contact time is met after contamination. Rationale: Any contact with a non-sterile surface compromises the antisepsis. NBSTSA Tip: The exam tests all-or-nothing aseptic principles. If contamination occurs, the antimicrobial action must be re-established.
At what specific point during the surgical hand scrub process should the subungual areas be cleaned, and with what tool?
Show answer →Subungual cleaning occurs during the initial wash/rinse phase under running water using a disposable nail cleaner (pick). Rationale: This removes debris from under the nails where microbial density is highest before the formal scrub begins. NBSTSA Tip: Ensure you identify this happens BEFORE the actual brush strokes or sponge application, not after the scrub is complete.
Which antiseptic agent is preferred for surgical hand scrubs due to its residual activity and ability to bind to the stratum corneum?
Show answer →Chlorhexidine Gluconate (CHG). Rationale: CHG provides a cumulative, persistent effect (up to 6 hours) by binding to skin proteins, whereas Povidone-Iodine is neutralized by blood and lacks significant residual activity. NBSTSA Tip: Differentiate between rapid kill (Alcohol) and persistent/residual kill (CHG) when choosing the best agent for long procedures.
After completing the surgical scrub, how should the ST dry their hands and arms to maintain aseptic technique?
Show answer →Use a sterile towel, drying from fingertips to elbows using a blotting motion; never return to a previously dried area. Rationale: Moving from cleanest (fingers) to least clean (elbows) prevents contamination. The towel is flipped to use a fresh section for the second arm. NBSTSA Tip: Distractors often suggest a rubbing motion or moving from elbow to hand; both are incorrect.
During the initial setup of the operating table, what is the mandatory placement of the patient safety strap, and what is the rationale for this specific location?
Show answer →The safety strap must be placed 2 inches proximal to the knees, over the thighs. Rationale: It prevents the patient from sliding or falling during table movements (Trendelenburg/Reverse) while avoiding pressure on the peroneal nerve or popliteal space. NBSTSA Tip: Always check for two-finger slack to avoid neurovascular compromise. Common distractor: Placing it over the knees (restricts movement/risks injury).
When positioning the Mayo stand over the sterile field for a laparotomy, what is the standard height and placement protocol to ensure both sterility and safety?
Show answer →The Mayo stand should be positioned slightly above the patient's legs without making contact. It must be locked in place. The CST should never lean on the Mayo stand. NBSTSA Focus: The sterile portion is only the top surface; the legs and underside are non-sterile. During setup, keep it away from the wall (12 inches) to prevent contamination before the patient enters.
Before the start of a total knee arthroplasty, the CST is responsible for testing the pneumatic tourniquet. What are the specific parameters for cuff selection and pressure settings per AORN/AST standards?
Show answer →Cuff selection: The widest cuff possible that covers the limb circumference without excessive overlap. Pressure: Settings are generally based on Limb Occlusion Pressure (LOP) or 100-150 mmHg above systolic blood pressure (SBP) for lower extremities. Key Exam Point: Documentation must include serial number, pressure, and inflation/deflation times. Distractor: Setting a standard 350 mmHg for all patients is incorrect; it must be individualized.
During a total mastectomy, the CST notes the patient's arm is abducted on an armboard at a 110-degree angle. Which nerve structure is at highest risk for stretch injury?
Show answer →The Brachial Plexus. NBSTSA standards and AORN guidelines dictate that arms must never be abducted more than 90 degrees. Abduction beyond this point causes the plexus to stretch over the humeral head, leading to potential permanent motor and sensory deficits. Exam Strategy: Differentiate between compression (e.g., ulnar) and stretch (e.g., brachial plexus) injuries; 90 degrees is the absolute limit for the CST exam.
A patient undergoing a 4-hour cystoscopy in lithotomy using candy-cane stirrups presents postoperatively with foot drop. Which nerve was most likely compressed?
Show answer →Common Peroneal (Fibular) Nerve. This nerve is highly susceptible to injury where it wraps around the lateral aspect of the fibular head. Compression occurs when the lateral knee rests against the metal stirrup without adequate padding. Clinical Pearl: Foot drop (inability to dorsiflex) is the classic CST exam indicator for peroneal nerve damage. Always ensure padding is placed between the fibula and the stirrup.
During a tympanoplasty, the CST notes the surgeon is about to use Chlorhexidine Gluconate (CHG) for the ear canal prep. Why must the CST intervene?
Show answer →CHG is strictly contraindicated for use in the middle ear due to its known ototoxicity, which can cause permanent sensorineural hearing loss. It is also contraindicated for the eyes (corneal damage) and neural tissue (neurotoxicity). For ear procedures, povidone-iodine (diluted/aqueous) or PCMX are the safest alternatives. NBSTSA Exam Tip: Always link CHG with the Three No's: No Eyes, No Ears (Middle/Inner), and No Brain/Spinal Cord.
An alcohol-based skin prep is used for a laparoscopic cholecystectomy. What is the minimum recommended drying time before draping according to 2026 standards?
Show answer →The minimum drying time is 3 minutes on hairless skin. If the prep pools (e.g., in the umbilicus) or is applied to hair-bearing areas, drying time must be extended. Draping before the prep is dry traps flammable vapors, creating a significant fire hazard when the ESU (Bovie) is activated. Exam Strategy: The NBSTSA emphasizes the Prep Time-Out and the specific 3-minute rule for alcohol-based solutions to prevent OR fires.
A surgical technologist is moving from the hallway to the instrument assembly area. Which attire is required for this specific semi-restricted zone?
Show answer →Semi-restricted areas (e.g., storage, corridors, instrument processing) require surgical scrubs, hair covers, and dedicated footwear. Masks are only required in Restricted areas (OR suites, sterile core, sub-sterile rooms). NBSTSA Tip: Remember that Semi-restricted is the most common distractor for questions regarding where masks must be worn.
To maintain a sterile environment, the air pressure in the OR suite must be maintained at what level relative to the surrounding corridors?
Show answer →Positive Pressure. Air flows from the OR (cleanest) to the corridors (less clean) to prevent contaminants from entering. NBSTSA Focus: The pressure must be at least 10% higher in the OR. If the door remains open, this pressure gradient is lost, increasing the risk of Surgical Site Infection (SSI).
During a colectomy, the surgeon complains the monopolar ESU is not cutting effectively despite increasing power. The CST notes the return electrode is secure. What is the next immediate troubleshooting step?
Show answer →Check the connection between the active electrode (handpiece) and the generator, then inspect the tip for eschar (charring). Eschar increases resistance and impedes current flow. NBSTSA Tip: Never simply increase power at the surgeon's request without checking the circuit. High power settings in the presence of a malfunction increase the risk of alternate site burns or insulation failure. Key Exam Point: If the ESU alarm sounds, the circuit is broken; if it works poorly without an alarm, the issue is usually resistance (eschar) or a faulty handpiece.
During an inguinal hernia repair, the patient suddenly exhibits unexplained tachycardia and a rapid rise in end-tidal CO2 (ETCO2). Which specific class of anesthetic agents is most likely responsible for triggering this hypermetabolic state?
Show answer →The primary triggers for Malignant Hyperthermia (MH) are volatile inhalation anesthetics (e.g., Isoflurane, Desflurane, Sevoflurane) and the depolarizing neuromuscular blocking agent Succinylcholine. Pathophysiology: These agents trigger an uncontrolled release of calcium from the sarcoplasmic reticulum in genetically susceptible individuals. Exam Strategy: NBSTSA often asks to identify safe versus unsafe agents. Remember: Nitrous oxide, local anesthetics, and non-depolarizing muscle relaxants (like Vecuronium) are NOT triggers for MH.
During a midline laparotomy, the surgeon asks for a blade to begin the incision. List the anatomical layers of the abdominal wall in the correct order from superficial to deep.
Show answer →1. Skin 2. Subcutaneous tissue (Camper's fascia - fatty layer; Scarpa's fascia - membranous layer) 3. Fascia/Aponeurosis (Linea alba in midline) 4. Preperitoneal fat 5. Peritoneum Clinical Pearl: In a midline approach, the rectus muscle is typically retracted laterally rather than incised. The Linea Alba is the primary fascial target for entry and closure. Exam Strategy: NBSTSA often tests the distinction between the two layers of the superficial fascia (Camper's vs. Scarpa's).
Which microorganism is used in biological indicators (BI) to monitor the effectiveness of steam sterilization, and why is this specific organism selected for this role?
Show answer →*Geobacillus stearothermophilus* is the organism of choice. It is used because it is highly resistant to moist heat but is non-pathogenic. It is a spore-forming bacterium; if the sterilization process kills these highly resistant spores, it is inferred that all other less resistant pathogens in the load have also been destroyed. **Exam Strategy:** NBSTSA frequently tests the specific names of organisms for different sterilization methods. Do not confuse this with *Bacillus atrophaeus* (used for EO and dry heat). High-yield point: *G. stearothermophilus* is also used for Hydrogen Peroxide Gas Plasma and Peracetic Acid monitoring.
17–20 correct
Strong. Move to the hardest material and timed drilling rather than re-reading topics you already know.
12–16 correct
A normal mid-prep score. Work the topics you missed one at a time — the topic pages below are built for exactly that.
Under 12 correct
Early days. Go topic by topic instead of taking more mixed tests: pick your weakest area below and drill it until the questions feel routine.
Procedures questions
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Equipment questions
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Safety questions
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Pharmacology questions
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Basics questions
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Management questions
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Pathology questions
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Anatomy questions
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Try 30 free CST cards firstIt is 20 real question-and-answer cards from our 1040-card CST deck, mixed across topics so it feels like the breadth of the exam. It is not the official NBSTSA exam and is not endorsed by NBSTSA — for the official outline and any official practice material, go to NBSTSA directly.
Use the bands on this page as study guidance, not as a pass mark: we do not publish a passing score for the CST because NBSTSA sets it, and it can change. Confirm the current standard in the official handbook.
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