sterilization & Disinfection
How should basins be positioned in the autoclave for sterilization? (A) Stacked on top of each other (B) On their sides (C) Upside down (D) Does not matter
(B) Basins, jars, cups, or other containers should be placed on their sides with the lid ajar so that air can flow out and steam can enter.
How long should the ET biological indicator be incubated before the reading is recorded? (A) 24 hours (B) 48 hours (C) 12 hours (D) 3 hours
(B) ETO biological indicators should be incubated for 48 hours before reading.
Why would gas sterilization be chosen over steam sterilization? (A) It is less expensive. (B) It is less damaging to items. (C) It is faster. (D) It is more effective.
(B) ETO gas is an effective substitute for most items that cannot be sterilized by heat or that would be damaged by repeated exposure to heat. It is noncorrosive and does not damage items. It completely penetrates porous materials.
ETO is mixed with carbon dioxide to: (A) increase antimicrobial effect (B) reduce flammability of ETO (C) reduce temperature requirement (D) increase microbial killing rate
(B) ETO is mixed with carbon dioxide to reduce the flammability of the ETO.
What method of sterilization is used on objects that cannot tolerate heat, moisture, and the presence of steam sterilization? (A) Gravity displacement (B) ETO (C) Hydrogen peroxide (D) Cidex
(B) ETO is used to sterilize objects that cannot tolerate heat, moisture, and the pressure of steam sterilization.
Whet spore is used to test steam under pressure (steam sterilizer)? (A) Clostridium perfringens (B) G. stearothermophilus (C) Treponema pallidum (D) Staphylococcus aureus
(B) G. stearothermophilus is the spore used to test steam under pressure sterilizers.
All of the following are true of dry heat sterilization EXCEPT: (A) the indicator used for dry heat ovens is B. atrophaeus (B) it is used only in an emergency in the operating room (C) sterilization occurs in mechanical convection ovens (D) sterilization occurs in gravity convection ovens
(B) Heat sterilization is not just used during emergencies.
The minimum exposure time for unwrapped instruments in a flash sterilizer that is set at 270°F (132°C) is: (A) 2 minutes (B) 3 minutes (C) 5 minutes (D) 7 minutes
(B) In a flash (high-speed pressure) sterilizer set at 270°F, the minimum exposure time is 3 minutes for unwrapped items. With this cycle, the entire time for starting, sterilizing, etc., is 6-7 minutes.
When placing tubing in an activated glutaraldehyde solution, one should: (A) use a shallow contriner (B) be certain that the interior of the tubing is completely filled (C) moisten it thorougny before submersion (D) Both B and C
(B) Lumens of instruments or tubing must be completely filled with solution. All items should be placed in a container deep enough to completely immerse them. All items should be dry before immersion so that the solution is not diluted.
Most packaged sterilized equipment from a manufacturer such as sutures, sponges, and disposable drapes is sterilized by means of: (A) ETO (B) cobalt-60 (ionizing radiation) (C) gravity displacement sterilizer (D) quaternary ammonium compounds
(B) Most equipment available that is packaged from the manufacturer has been sterilized by cobalt-60 or ionizing radiation. This process is restricted to commercial use because of its expense.
Which of the following is not a method of sterilization but is a heating process that destroys microorganisms at a temperature and exposure time and does not alter their chemical makeup? (A) Decontamination (B) Pasteurization (C) Hydrogen peroxide plasma sterilization (D) ETO gas sterilization
(B) Pasteurization is a heating process that destroys microorganisms at a certain temperature and exposure time but does not alter their chemical makeup.
All of the following are true regarding prions EXCEPT: (A) They cause Creutzfeldt-Jakob disease. (B) They contain DNA/RNA. (C) They are not viral, bacterial, or fungal. (D) When performing surgery on a patient that is infected with a prion, disposable instruments should be used.
(B) Prions do not contain DNA/RNA.
"Slow exhaust" in a gravity displacement steam sterilizer is used for: (A) plastics (B) solutions (C) rubber (D) drape packs
(B) Solutions are sterilized alone on slow exhaust so solutions will not boil over and so caps will not blow off.
What is the test that is used to check for air trapped in the prevacuum sterilizer? (A) Biological indicator (B) Bowie-Dick test (C) Chemical indicator (D) Prevacuum test
(B) The Bowie-Dick test is used to check for air trapped in the prevacuum sterilizer. The biological indictor is the most effective indicator to prove sterility. A chemical indicator is tape used in the autoclave.
Instrumentation and equipment are processed according to their level of risk. This system is known as: (A) evidence-based practice (B) the Spaulding method (C) reprocessing (D) central monitoring
(B) The Spaulding system assigns a risk category that is specific to the regions of the body in which a device is to be used.
The bacterial spore used in the biological indicator for steam sterilization is Geobacillus stearothermophilus. This is placed in the bottom front of the sterilizer, also known as the coldest point of the sterilizer. Following the sterilization process, the biological indicator is removed, crushed, and incubated. What should the color of the growth medium be if the spores were killed and the sterilization process was successful? (A) Fluorescent yellow (B) Red (C) Blue (D) It remains red for 60 minutes and then turns fluorescent yellow
(B) The bacterial spore should remain red following the sterilization process. If it turns yellow, the results are positive, meaning the sterilization conditions were not met and the items are considered NOT sterile. The items in the load must immediately be recalled and reprocessed, and the autoclave must be checked for a malfunction.
The process called cavitation occurs in the: (A) moist heat sterilizer (B) ultrasonic cleaner (C) high-speed pressure sterilizer (D) washer-sterilizer
(B) The ultrasonic cleaner (which is not a sterilizer) utilizes ultrasonic energy and high-frequency sound waves. Instruments are cleaned by cavitation. In this process, tiny bubbles are generated by high-frequency sound waves. These bubbles generate minute vacuum areas that dislodge, dissolve, or disperse soil.
To achieve 270°F, the required pressure is: (A) 15 psi (B) 20 psi (C) 27 psi (D) 40 psi
(C) The laws of physics tell us that to raise the temperature of steam, we must also raise the pressure in the closed sterilization chamber; to achieve 270°F, the required pressure is 27 psi.
Activated glutaraldehyde is used to disinfect endoscopes for: (A) 5 minutes (B) 10 minutes (C) 20 minutes (D) 60 minutes
(C) A minimum of 20 minutes is used to kill vegetative bacteria, fungi, hepatitis B, and HIV. A minimum of 45 minutes is required for tuberculocidal activity.
Personal protective equipment (PPE) includes all of the following EXCEPT: (A) protective eyewear (B) facemask (C) surgical and/or patient care gloves (D) full protective body suit or gown
(C) All staff members who work in the decontamination area must wear PPE in compliance with government regulations. Only gloves approved for contact with chemical disinfectants are used. Surgical gloves and patient care gloves are not permitted.
Gastrointestinal endoscopes are characterized as ________ under the Spaulding sterilization system. (A) critical (B) noncritical (C) semicritical (D) Scopes are not considered in the Spauld- ing system
(C) Gastrointestinal scopes come in contact with mucous membranes or nonintact skin. They are semicritical items.
All of the following statements regarding instrument sets are true EXCEPT: (A) instruments must be placed in perforated trays (B) heavy instruments are placed on the bottom (C) all instruments must be closed (D) all detachable parts must be disassembled
(C) Hinged instruments must be open with box locks unlocked to permit steam contact on all surfaces. All detachable parts should be disassembled.
To kill spores, an item must be immersed in a 2% aqueous solution of glutaraldehyde for: (A) 20 minutes (B) 2 hours (C) 10 hours (D) 24 hours
(C) Immersion in a 2% aqueous solution of activated, buffered alkaline glutaraldehyde is sporicidal (kills spores) within 10 hours. It is chosen for heat-sensitive items that cannot be steamed or if ETO gas is unavailable of impractical.
In which procedure would the use of a high-level disinfectant be acceptable instrument preparation? (A) Suction lipectomy (B) Tracheotomy (C) Cystoscopy (D) Mediastinoscopy
(C) In cystoscopy, sterilization of instruments with steam or ETO provides the greatest elimination of the risk of infection; however, it is not essential. High-level disinfection is recommended and provides reasonable assurance that items are safe to use.
In a gravity displacement sterilizer, steam enters the chamber at the _______. (A) bottom (B) bottom back (C) top rear (D) top front
(C) In the gravity displacement autoclave, steam enters at the top rear and displaces the air and exits through a drain at the front bottom of the chamber.
A wrapped tray of instruments is sterilized in a gravity displacement sterilizer at 250°F for: (A) 10 minutes (B) 15 minutes (C) 30 minutes (D) 40 minutes
(C) Instruments wrapped as a set in double-thickness wrappers are autoclaved at a setting of 250°F for 30 minutes.
What is the role of moisture in ETO sterilization? (A) The items will dry out during the process if no humidity is added. (B) The sterilizer will deteriorate from gas over a period of time if no moisture is added. (C) Dried spores are resistant to the gas, so they must be hydrated. (D) Moisture is not an essential element in gas sterilization.
(C) Moisture is essential in gas sterilization. Desiccated or highly dried bacterial spores are resistant to ETO gas; therefore, they must be hydrated in order for the gas to be effective.
_______ is when different organisms exist and benefit from each other. __________ is when one organism benefits from the other and neither is harmed. _________ is when one organism benefits from the other and harms the host. 1. Parasitism, 2. Mutualism, 3. Commensalism (A) 1, 2, 3 (B) 3, 2, 1 (C) 2, 3, 1 (D) 1, 3, 2
(C) Mutualism, commensalism, and parasitism.
Chemical monitors are placed inside and outside of all packs to be sterilized. These monitors show that: (A) the item is sterile (B) proper packaging is achieved (C) parameters, such as heat and pressure, have been reached (D) the proper time has been met
(C) Subjecting items to the process of sterilization does not ensure that the item is sterile, but only that the parameters such as heat and pressure have been met.
All of the following apply to the daily air removal test (DART) test EXCEPT: (A) it is a preassembled type of Bowie-Dick test monitor (B) it is used in a prevacuum sterilizer (C) this test is done to determine that sterilization has occurred (D) this test is done daily to check for air removal and air entrapment
(C) The DART test is performed daily in a prevacuum sterilizer to make sure air is properly removed for the sterilization process to be performed properly.
Instruments and equipment are processed according to their level of risk. This system is known as: (A) ETO sterilization (B) event-related sterility (C) the Spaulding method (D) instrument cleaning and disinfection
(C) The Spaulding method is used to rate the level of risk when processing equipment.
Glutaraldehyde is a high-level disinfectant, that is, a sporicidal, a bactericidal, and a viricidal. At a 2% concentration for ________ it is also a tuberculocidal. (A) 10 minutes (B) 15 minutes (C) 20 minutes (D) 40 minutes
(C) Two percent glutaraldehyde is a tuberculocidal when an item is sterilized for 20 minutes.
The process of terminal decontamination follows every surgical case. Decontamination of the walls consists of: (A) cleaning all walls up to 3 ft (B) cleaning all walls up to 1 ft (C) spot cleaning where soiled (D) always cleaning with alcohol
(C) Walls, doors, surgical lights, and ceilings are spot cleaned if they are soiled with blood tissue or body fluids.
According to the Spaulding system, what risk is assigned to sterile body tissue, including the vascular system? (A) Critical (B) Semicritical (C) Noncritical (D) Intermediately critical
(A) Critical risk is assigned to sterile body tissues including the vascular system.
Why is ETO diluted with an inert gas? (A) It increases its effective sterilization. (B) It adds convenience and speed. (C) It adds humidity. (D) It helps with aeration.
(A) When blended with inert gas, ETO produces effective sterilization by destroying DNA and the protein structure of microorganisms.
In a high-speed flash sterilizer, unwrapped instruments are exposed for a minimum of: (A) 1 minute (B) 3 minutes (C) 5 minutes (D) 10 minutes
(B) The minimum exposure time at 270°F with 27 psi is 3 minutes for unwrapped non-porous items.
What chemical system uses peracetic acid as the sterilant? (A) Ozone gas sterilization (B) STERIS (C) Sterrad (D) Vapor phase sterilizer
(B) A proprietary (STERIS) chemical formulation of peracetic acid, hydrogen peroxide, and water causes cell death by inactivating the cell systems.
An obligatory parasite is: (A) a type of prion (B) a type of microorganism that depends on living tissue to survive (C) a type of microorganism that depends on dead tissue to survive facultative parasite (D) All of the above
(B) An obligatory parasite is a type of microorganism that depends on living tissue to survive.
The lumen of a tubing undergoing ethylene oxide (ETO) sterilization is: (A) well lubricated (B) dried thoroughly (C) prepared with a residual of distilled water (D) prepared with a NaCl flush
(B) Any tubing or other item with a lumen should be blown out with air to force dry before packaging because water combines with ETO gas to form a harmful acid, ethylene glycol.
What is the function of an aerator in ETO sterilization? (A) After the sterilization process, aeration is necessary to remove the toxic gas. (B) Recommendations are for the sterilizer and aerator to be part of the same machine. (C) It is used to aerate items before sterilization. (D) Both A and B
(D) An aeration process is essential for the ETO machine to remove the toxic gas. The most favorable situation is for them to be located in the same machine.
Bioterrorist agents include all of the following EXCEPT: (A) anthrax (B) botulism (C) smallpox (D) bubonic plague
(D) Anthrax, botulism, and smallpox are bioterrorist agents.
The bacteria used for the biological monitor in ETO is: (A) G. stearothermophilus (B) Bacillus atrophaeus (C) Bacillus subtilis (D) Both B and C
(D) B. atrophaeus and B. subtilis can both be used for ETO; G. stearothermophilus is used in steam sterilization
The chemical agent used in gas sterilization is: (A) ethylene glycol (B) ethacrynate sodium (C) ethyl chloride (D) ethylene oxide
(D) ETO gas is used to sterilize items that are either heat or moisture sensitive. It kills microorganisms, including spores, by interfering with the normal metabolism of protein and reproductive processes.
Sterility was previously measured by time, but this is now considered invalid. The principle now used is: (A) carefully checking sterile indicators (B) event-related sterility (C) terminal sterilization (D) Both B and C
(D) Event-related sterility or terminal sterilization is based on the principle that sterilized items are assumed sterile between uses unless environmental conditions or events interfere with the integrity of the package.
The commercial name for glutaraldehyde is: (A) peracetic acid (B) phenol (C) Quats (D) Cidex
(D) Glutaraldehyde, a high-level disinfectant, is known commercially as Cidex.
Gravity displacement utilizes _______ to destroy microorganisms. (A) gas (B) radiation (C) gamma rays (D) steam
(D) Gravity displacement utilizes steam under pressure to effect moist heat sterilization.
All of the following statements regarding wrapping materials are true EXCEPT: (A) Disposable nonwoven wrappers are intended for one use only. (B) You can use two 140 thread count per square inch. (C) You can use one 280-thread count per square inch. (D) Peel pouches can be used on all instruments including large heavy instruments and micro instruments.
(D) Peel pouches are intended for lightweight instruments and devices.
The chemical sterilant used in the STERIS method of sterilizing is: (A) formaldehyde (B) Cidex (C) ETO (D) peracetic acid
(D) Peracetic acid or acetic acid mixed with a solution of salts (Bionox) kills microorganisms. It is used only in the STERIS system for heat-sensitive and immersible instruments. Processing is 20-30 minutes, and temperature is controlled at 131°F; it is cost effective and environmentally friendly.
All of the following apply to the prevacuum autoclave EXCEPT: (A) it is also called a dynamic air removal autoclave (B) the vacuum pump located in the bottom front removes the air from the chamber (C) the Bowie-Dick test must be used to confirm air removal (D) the most common temperature used with the prevacuum sterilizer is 250°F 27 psi
(D) Prevacuum autoclaves are also called dynamic air removal autoclaves. A vacuum pump is used to evacuate the air, which is why a Bowie-Dick/DART test is required to make sure the air is removed. Prevacuum autoclaves work at higher temperatures of 270°F and 27 psi, and gravity sterilizers work at lower temperatures 250°F and 15-17 psi.
When steam is used to sterilize rubber tubing or a catheter: (A) the lumen must be dried thoroughly before the process begins (B) a rubber band may be placed around it so it does not unwind (C) it should be fanfolded before wrapping (D) a residual of distilled water should be left inside the lumen
(D) Rubber tubing should not be folded or kinked because steam can neither penetrate it nor displace air from folds. A residual of distilled water should be left in the lumen. Rubber bands must not be used around solid items because stearn cannot penetrate through or under rubber.
New infectious diseases emerging in the United States include: (A) SARS (B) West Nile virus (C) avian influenza (D) All of the above
(D) SARS, West Nile virus, and avian flu are all infectious diseases emerging in the United States.
All of the following statements regarding steam sterilization are true EXCEPT: (A) flat packages are placed on the shelf on edge (B) small packages, placed one on top of the other, are crisscrossed (C) basins are placed on their sides (D) solutions may be autoclaved along with other items as long as they are on a shelf alone
(D) Solutions are sterilized alone on a slow exhaust cycle to prevent them from boiling over. The pressure gauge must read 0°F before opening the door. This is so the caps will not pop off.
Toxic anterior segment syndrome (TASS) can be attributed to: (A) contaminated ultrasonic machines (B) enzymatic residue left on eye instrumentation (C) incomplete instrument cleaning (D) All of the above
(D) TASS is an acute inflammatory condition affecting the anterior segment of the eye containing the cornea, iris, ciliary body, and lens. It is seen postoperatively after cataract surgery. The condition is attributed to improper instrument reprocessing, including contaminated ultrasonic machines, enzymatic residue left on eye instrumentation, and incomplete instrument cleaning.
Which of the following statements regarding the sterilization of basin sets is TRUE? (A) Basins must be separated by a porous material if they are nested. (B) Sponges and linen may be packaged inside the basin to be sterilized. (C) Basins are placed flat in the autoclave. (D) Basins must always be placed on the top shelf of the autoclave in a combined load.
(A) Basins and solid utensils must be separated by a porous material if they are nested to permit permeation of steam around all surfaces and condensation of steam from the inside during sterilization. Sponges and linen are not packaged in basins.
Bioburden refers to: (A) the degree of microbial contamination (B) a hospital-acquired infection (C) a chemical agent (D) high-level disinfectant
(A) Bioburden is the number and type of live bacterial colonies on the surface before it is sterilized.
ETO destroys cells by: (A) interfering with the normal metabolism of the protein and reproductive processes (B) coagulating cell protein (C) converting ions to thermal and chemical energy, causing cell death (D) shrinking the cell
(A) ETO is a chemical agent that kills microorganisms, including spores. It interferes with the normal metabolism of protein and reproductive processes, resulting in cell death.
All of the following are environmental disinfectants used for low-level disinfection and terminal decontamination EXCEPT: (A) glutaraldehyde (B) hypochlorite (C) quaternary ammonium compound (D) alcohol
(A) Environmental disinfectants that are used for routine low-level disinfection and terminal decontamination include phenolics, quats, hypochlorites, and alcohol. Glutaraldehyde is a high-level disinfectant known as Cidex commonly used on instruments.
The amount of pressure necessary in a steam sterilizer set at 250°F is: (A) 15-17 lb (B) 20-22 lb (C) 22-25 lb (D) 25-27 lb
(A) Fifteen to seventeen pounds of pressure are necessary in the steam sterilizer set at 250°F. It is 27 psi if set at 270°F.
What is the shelf life of Cidex? (A) 14 days (B) 7 days (C) 1 month (D) Indefinite
(A) Glutaraldehyde must be renewed after 14 days because it becomes ineffective after that time.
Gravity displacement steam sterilizers operate on the principle that: (A) air is heavier than steam (B) air and steam have equal weight (C) steam is heavier than air (D) water is heavier than air
(A) Gravity displacement steam sterilizers operate on the principle that air is heavier than steam. Steam is forced into the inner chamber. Any air in the inner chamber blocks the passage of pressurized steam and prevents sterilization.
Hydrogen peroxide plasma sterilization utilizes: (A) a cloud or glow of pink plasma sterilization (B) a chamber much like a microwave (C) a hydrogen peroxide solution D) All of the above
(A) Hydrogen peroxide plasma sterilization utilizes a cloud or glow of pink plasma covering the items to be sterilized.
For ETO sterilization, how long must instruments remain in the aerator being operated at 140°F? (A) 8 hours (B) 6 hours (C) 4 hours (D) 2 hours
(A) Instruments must remain in the aerator cycle of the ETO at 140°F for 8 hours.
Following a surgical procedure, the first step in the intraoperative decontamination process is for the STSR to rinse off the instruments with water and use a lap pad or towel to remove blood and debris. Once taken to the decontamination room, how soon should the instruments be cleaned? (A) Within 20 minutes (B) Within 1 hour (C) There is no set time constraint (D) According to manufacturer's instructions
(A) Instruments should be washed within 20 minutes of arriving to the decontamination Room to prevent blood and tissue from totally drying on the instruments, which makes the sterilization process more time consuming.
All of the following apply to immediate-use steam sterilization (IUSS) EXCEPT: (A) items used for IUSS must always be wrapped (B) implants should never be sterilized immediately before use except in a documented emergency situation when there is no other option (C) immediate use sterilizers must be located where sterile items can be transported directly from the autoclave to the sterile field (ie, substerile room) (D) items used for IUSS are never wrapped unless specified by the manufacturer
(A) Items sterilized by IUSS should never be wrapped unless specified by the manufacturer. There are very strict guidelines for this.
To be sterilized effectively, a linen pack must not weigh more than: (A) 12 lb (B) 14 lb (C) 16 lb (D) 18 lb
(A) Linen packs must not weigh more than 12 lb. Linen must be freshly laundered. Items must be fanfolded or loosely rolled.
Which type of immunity occurs when you are exposed to the disease and as a result you become immune? (A) Naturally acquired active immunity (B) Artificially acquired active immunity (C) Artificially acquired passive immunity (D) Naturally acquired passive immunity
(A) Naturally acquired active immunity is when you are exposed to the disease and as a result become immune. Artificially acquired active immunity is when you receive a vaccine and become immune. Artificially acquired passive immunity is when you receive immunization such as gamma globulin. It is a short-term immunization. Naturally acquired passive immunity occurs during pregnancy when a pregnant woman passes the antibodies to her fetus through the bloodstream.
Positive assurance that sterilization conditions have been achieved can only be obtained through: (A) biological control test (B) heat-sensitive tape (C) color change monitor (D) mechanical indicator
(A) Positive assurance that sterile conditions have been achieved by steam, ETO, or dry heat sterilization can be obtained only through a biological control test. These should be done at least weekly. The most dependable is a preparation of living spores resistant to the sterilizing agent.
The chemical name for common household bleach is: (A) sodium hypochlorite (B) quaternary ammonium compounds (C) petroleum products (D) hydrogen peroxide
(A) Sodium hypochlorite is the chemical name for household bleach.
Which of the following kills bacterial spores? (A) Sterilant (B) Germicide (C) Antiseptic (D) Fungicide
(A) Spores are not killed unless an item is sterilized.
Who is responsible for transporting instrumentation postoperatively to the decontamination room following the surgical procedure: (A) STSR (B) circulator (C) first assistant (D) All of the above
(A) The surgical technologist in the scrub role is responsible for transporting dirty instrumentation, equipment, and supplies to the decontamination room.
Which organization regulates the production of biological sterilization test packs in house? (A) Centers for Disease Control and Prevention (CDC) (B) Food and Drug Administration (FDA) (C) American Medical Association (AMA) (D) Association for the Advancement of Medical Instrumentation (AAMI)
(D) The AAMI develops standards for the safety, use, and management of medical devices and health technologies. In regard to sterilization, it provides guidance to health care personnel who use steam for sterilization (the test packs containing the vial with the bacterial spore). - - The CDC provides health information on disease control and prevention. - The FDA is responsible for protecting the public by providing information and regulating drugs, biological products, medical devices, food, cosmetics, and many other products. - The AMA provides medical education.
The only antibiotic that treats MRSA is: (A) gentamycin (B) amoxicillin (C) tobramycin (D) vancomycin
(D) Vancomycin is the antibiotic used to treat MRSA.
Wrapped basin sets may be sterilized by steam under pressure at 250°F for a minimum of: (A) 5 minutes (B) 10 minutes (C) 15 minutes (D) 20 minutes
(D) Wrapped basin sets are sterilized at 250°F for a minimum of 20 minutes. They are placed on their sides to allow air to flow out of them. This also helps water flow out.
