Chapter 9 - Instrument Preparation, Antisepsis and Desinfection Flashcards
Which microorganism can survive for over 90 days on pure polyester material?
A) Clostridium difficile
B) Staphylococci
C) Pseudomonas aeruginosa
D) Enterococci
B) Staphylococci
What is a recommended laundry temperature for cleaning contaminated hospital textiles according to the US Centers for Disease Control and Prevention (CDC)?
A) 120°F (49°C)
B) 140°F (60°C)
C) 160°F (70°C)
D) 180°F (82°C)
C) 160°F (70°C)
How are instruments classified for sterilization and disinfection purposes based on their risk for infection?
A) Nonsterile, semi-sterile, sterile
B) Low-risk, medium-risk, high-risk
C) Noncritical, semicritical, critical
D) Basic, intermediate, advanced
C) Noncritical, semicritical, critical
What is the primary distinction between sterilization and disinfection?
A) Sterilization destroys all microbial life including spores
B) Disinfection eliminates spores but not vegetative bacteria
C) Sterilization is only for surgical tools
D) Disinfection can be applied to living tissue
A) Sterilization destroys all microbial life including spores
Which sterilization method is commonly used in health care facilities?
A) Cold water immersion
B) Steam under pressure
C) Liquid soap disinfection
D) Ultraviolet light
B) Steam under pressure
What is a key factor that affects the efficacy of disinfection and sterilization?
A) Type of medical device used
B) Temperature and pH of the process
C) Time of day the process is performed
D) Length of the surgery
B) Temperature and pH of the process
What is the risk if the preparation and packing process is not regarded as clean?
A) Increased turnaround time
B) Recontamination with organic material
C) Loss of instrument functionality
D) Delay in surgical procedures
B) Recontamination with organic material
What is the role of antiseptics in the disinfection process?
A) They are toxic to living tissues
B) They are used only on inanimate objects
C) They are nontoxic to living tissues
D) They eliminate bacterial spores
A) They are toxic to living tissues
Which chemical method is NOT commonly used for sterilization in healthcare facilities?
A) Dry heat
B) Ethylene oxide (EtO) gas
C) Hydrogen peroxide gas plasma
D) Cold-water disinfection
D) Cold-water disinfection
What is a critical factor to consider when applying disinfectants to inanimate objects?
A) Temperature of the room
B) Toxicity to living tissues
C) Color of the disinfectant
D) Contact time and concentration
D) Contact time and concentration
What is the main difference between a disinfectant and an antiseptic?
A) Disinfectants are for living tissues, while antiseptics are for objects
B) Disinfectants are for inanimate objects, while antiseptics are for living tissues
C) Disinfectants kill all microorganisms, while antiseptics kill spores
D) Disinfectants are more effective than antiseptics
B) Disinfectants are for inanimate objects, while antiseptics are for living tissues
What method of sterilization is typically used for instruments that cannot withstand high heat?
A) Cold sterilization
B) Steam sterilization
C) Dry heat sterilization
D) Ethylene oxide (EtO) gas sterilization
D) Ethylene oxide (EtO) gas sterilization
How does water hardness affect the cleaning process?
A) Increases cleaning efficiency
B) Reduces effectiveness of blood removal in cold water prewashes
C) Has no effect on cleaning
D) Speeds up the sterilization process
B) Reduces effectiveness of blood removal in cold water prewashes
What is a prerinsing alternative to manual cleaning for surgical instruments?
A) Alcohol-based rinses
B) Enzymatic detergent solution
C) Boiling in water
D) Chlorine rinse
B) Enzymatic detergent solution
How long does a typical enzymatic detergent need for effective cleaning at room temperature?
A) 2-5 minutes
B) 10-20 minutes
C) 30-45 minutes
D) 1-2 hours
C) 30-45 minutes
What type of detergent solution is recommended after prewashing instruments?
A) Acidic
B) Neutral or near-neutral pH
C) Alkaline
D) Chlorine-based
B) Neutral or near-neutral pH
What should be used to clean instruments containing narrow lumens?
A) Metal brushes
B) Compressed air and soft, lint-free cloths
C) Steel wool
D) Household cleaning agents
B) Compressed air and soft, lint-free cloths
After cleaning, how should surgical instruments ideally be dried?
A) Air-dried
B) Dried with compressed air
C) Towel dried
D) Left in direct sunlight
B) Dried with compressed air
What cleaning method is most effective at removing impacted debris from complex surfaces?
A) Manual scrubbing
B) Boiling in water
C) Ultrasonic cleaning
D) Alcohol-based cleaning
C) Ultrasonic cleaning
Which detergent is preferred during ultrasonic cleaning?
A) Foaming enzymatic detergent
B) Nonfoaming enzymatic detergent
C) Alcohol-based detergent
D) Neutral pH detergent
B) Nonfoaming enzymatic detergent
Why must instruments be rinsed after ultrasonic cleaning?
A) To remove water
B) To cool them down
C) To remove loosened debris and cleaner residues
D) To sanitize them
C) To remove loosened debris and cleaner residues
What is the function of an automated washer–disinfector in the cleaning process?
A) To sterilize instruments
B) To combine cleaning with heat disinfection
C) To lubricate instruments
D) To dry instruments
B) To combine cleaning with heat disinfection
What temperature is achieved during the disinfection phase in an automated washer–disinfector?
A) 60-65°C
B) 70-75°C
C) 90-93°C
D) 100°C
C) 90-93°C
What is the A0-value in the context of disinfection?
A) A measure of time at 100°C
B) A pH measurement
C) A time-temperature equivalent used to measure disinfection effectiveness
D) A measurement of mechanical cleaning efficiency
C) A time-temperature equivalent used to measure disinfection effectiveness
What is the recommended A0-value for highly secure disinfection?
A) 1000
B) 2000
C) 5000
D) 10,000
C) 5000
What type of lubricant should be used on surgical instruments before sterilization?
A) Oil-based lubricants
B) Water-soluble lubricants
C) Grease-based lubricants
D) Alcohol-based lubricants
B) Water-soluble lubricants
How should hinged instruments be packed before sterilization?
A) Closed
B) Partially opened
C) Fully opened
D) Disassembled
C) Fully opened
What is the most effective wrapping material for sterilization?
A) Cotton
B) Linen fabrics
C) Disposable nonwoven wrappers
D) Paper
C) Disposable nonwoven wrappers
Why is cotton fabric not ideal for wrapping instruments for sterilization?
A) It allows moisture to pass through
B) It is too strong for autoclaving
C) It damages the instruments
D) It prevents proper sterilization
A) It allows moisture to pass through
What type of instrument packaging is not compatible with hydrogen peroxide gas plasma sterilization?
A) Aluminum composite containers
B) Paper pouches
C) Cellulose-containing materials
D) Synthetic nonwoven materials
C) Cellulose-containing materials
What should be done if a surgical pack becomes wet?
A) Let it dry and store it
B) Use it within 24 hours
C) Reprocess it
D) Store it separately from other packs
C) Reprocess it
Why is it important to maintain relative humidity and temperature during packing?
A) To ensure packaging is easy
B) To avoid the instruments rusting
C) To prevent condensate buildup and contamination
D) To achieve faster sterilization
C) To prevent condensate buildup and contamination
What is the shelf life of surgical packs in disposable nonwoven wrappers?
A) 30 days
B) 90 days
C) 1 year
D) Indefinite
C) 1 year
Why should packing materials be at room temperature before sterilization?
A) To prevent condensation and ensure sterility
B) To avoid damaging the instruments
C) To ensure faster drying
D) To increase sterilization effectiveness
A) To prevent condensation and ensure sterility
What is the advantage of using double packaging for surgical instruments?
A) Increases sterilization speed
B) Increases shelf life and extra security during surgery
C) Reduces weight of the pack
D) Avoids using disposable pouches
B) Increases shelf life and extra security during surgery
Which environmental factors increase the risk of contamination of surgical packs?
A) Bioburden and traffic
B) Lighting and storage temperature
C) Noise levels and cleanliness
D) Distance from the sterilization unit
A) Bioburden and traffic
When should sterility maintenance covers be applied?
A) Before sterilization begins
B) During the drying process
C) After items are cool and dry
D) Immediately after the sterilization process
C) After items are cool and dry
What contamination risk is common during the unpacking of surgical instruments?
A) Airborne contamination
B) Temperature fluctuations
C) Improper handling
D) Lack of sterilization indicators
C) Improper handling
Which type of contamination is most common in processed surgical instruments?
A) Fungal
B) Viral
C) Protein residues and biofilm
D) Prions
C) Protein residues and biofilm
Which instrument design increases the adherence of biofilm?
A) Smooth surfaces
B) Instruments with lumens and crevices
C) Stainless steel tools
D) Short and simple tools
B) Instruments with lumens and crevices
Which of the following is a key factor in reducing biofilm formation?
A) Using chemical sterilizers
B) Delaying the sterilization process
C) Shortening the time between use and reprocessing
D) Increasing water temperature
C) Shortening the time between use and reprocessing
ATP bioluminescence tests are used to detect:
A) Heat sterilization effectiveness
B) Residual contamination
C) Humidity levels in storage rooms
D) Proper mechanical indicator function
B) Residual contamination
Which sterilization indicator provides the highest level of sterility assurance?
A) Chemical indicators
B) Mechanical indicators
C) Biological indicators
D) Temperature gauges
C) Biological indicators
How should bowls be arranged in an autoclave to ensure proper sterilization?
A) Placed flat on the surface
B) Stacked on top of each other
C) With openings facing down or to the side
D) Filled with water
C) With openings facing down or to the side
Which type of bacteria spores are used to calibrate steam sterilization effectiveness?
A) Coagulase-negative staphylococci
B) Bacillus subtilis
C) Geobacillus stearothermophilus
D) Escherichia coli
C) Geobacillus stearothermophilus
Why should packs be loaded loosely in the autoclave?
A) To prevent moisture buildup
B) To allow for even steam circulation
C) To reduce the number of packs sterilized at once
D) To protect them from physical damage
B) To allow for even steam circulation
What is a critical feature of proper sterilization in valve containers?
A) Sealing the container tightly
B) Using chemical sterilants inside
C) Ensuring the valve is open
D) Adding extra cotton plugs inside
C) Ensuring the valve is open
What happens when steam contacts a cooler surface during sterilization?
A) Evaporation
B) Condensation
C) Temperature equalization
D) Air displacement
B) Condensation
What is the recommended drying time for low-density items like plastic or rubber after steam sterilization?
A) 5 minutes
B) 15 to 30 minutes
C) 60 minutes
D) No drying time is needed
B) 15 to 30 minutes
What is the purpose of the Bowie-Dick test?
A) To check for leaks in autoclaves
B) To confirm that air removal and steam penetration are complete
C) To measure ATP levels in autoclaves
D) To test mechanical indicator accuracy
B) To confirm that air removal and steam penetration are complete
Why is prion contamination a concern in ruminant surgeries?
A) Prions are easily destroyed by steam sterilization
B) Prions resist conventional sterilization methods
C) Prions are not transmitted through surgical instruments
D) Prions are only found in humans
B) Prions resist conventional sterilization methods
What sterilization process is used for items sensitive to heat or chemicals?
A) Steam sterilization
B) Filtration
C) Radiation
D) Ultrasonic cleaning
C) Radiation
Why should instruments be allowed to cool before applying sterility maintenance covers?
A) To avoid plastic degradation
B) To prevent condensation
C) To enhance chemical indicator effectiveness
D) To ensure quicker storage
B) To prevent condensation
Why is air displacement by steam critical in an autoclave?
A) To prevent the formation of air pockets
B) To ensure rapid cooling of instruments
C) To create high-temperature dry heat
D) To increase the pressure inside the autoclave
A) To prevent the formation of air pockets
Which type of filtration is commonly used for the preparation of small volumes of fluids in practice settings?
A) Depth filtration
B) Surface filtration
C) Sieve filtration
D) Ultraviolet filtration
A) Depth filtration
When loading items into an autoclave, how should single pouches be placed?
A) Laid flat on the surface
B) Stacked on top of each other
C) Spaced properly in racks
D) Placed inside another sterilized container
C) Spaced properly in racks
Why should valves in cannulas be left open during autoclaving?
A) To prevent pressure buildup
B) To allow proper steam penetration
C) To avoid condensation
D) To preserve valve function
B) To allow proper steam penetration
How should heavier or denser items be positioned inside the autoclave?
A) Placed on the top shelves
B) Placed on the bottom shelves
C) Placed in the middle of the load
D) Stacked in layers
B) Placed on the bottom shelves
What is the key factor in ensuring asepsis during steam sterilization?
A) High air pressure
B) Proper heat distribution
C) Control of time, temperature, and pressure
D) Use of chemical indicators inside the pack
C) Control of time, temperature, and pressure
Which factor contributes to the recontamination risk in improperly functioning autoclaves?
A) Inadequate drying times
B) Excessive exposure to heat
C) Leakages in the autoclave system
D) Overuse of sterilization chemicals
C) Leakages in the autoclave system
The SAL of a sterilization process is described by:
A) Time to achieve complete sterilization
B) The likelihood of contamination after sterilization
C) Temperature and pressure readings in the autoclave
D) The color change in the chemical indicator
B) The likelihood of contamination after sterilization
How do chemical indicators help during the sterilization process?
A) By guaranteeing complete sterilization
B) By providing evidence that packs have reached sterilization temperatures
C) By detecting bioburden inside the pack
D) By neutralizing any residual contamination
B) By providing evidence that packs have reached sterilization temperatures
Which microorganisms are typically used to test biological sterilization indicators?
A) E. coli
B) Prions
C) Heat-resistant bacterial spores
D) Biofilm-forming bacteria
C) Heat-resistant bacterial spores
What is the function of the mechanical indicators used in sterilization?
A) To monitor bioburden on instruments
B) To detect temperature and pressure fluctuations
C) To control the drying process
D) To track the type of sterilization cycle used
B) To detect temperature and pressure fluctuations
Flash sterilization is contraindicated for:
A) Surgical tools made of plastic
B) Instruments contaminated during surgery
C) Implantable devices
D) Non-porous instruments
C) Implantable devices
What is the primary purpose of low-temperature sterilization (LTS)?
A) Sterilizing heat-tolerant instruments B) Sterilizing instruments that cannot withstand high temperatures C) Sterilizing large, simple instruments D) Sterilizing instruments without pre-cleaning
B) Sterilizing instruments that cannot withstand high temperatures
How does lumen diameter affect hydrogen peroxide gas plasma sterilization?
A) Smaller diameter improves efficacy B) Smaller diameter decreases efficacy C) Diameter does not affect sterilization D) Larger diameter decreases efficacy
B) Smaller diameter decreases efficacy
thylene oxide (EtO) kills microorganisms by:
A) Causing dehydration B) Inactivating proteins, DNA, and RNA C) Disrupting cell membranes D) Oxidizing enzymes
B) Inactivating proteins, DNA, and RNA
What is typically mixed with ethylene oxide to reduce flammability?
A) CO2 or Freon B) Nitrogen C) Oxygen D) Helium
A) CO2 or Freon
What environmental concern is associated with Freon used with EtO?
A) It is toxic to humans B) It contributes to ozone depletion C) It creates toxic by-products D) It is a greenhouse gas
B) It contributes to ozone depletion
What is the preferred diluent for EtO sterilization?
A) Oxygen B) Freon C) CO2 D) Nitrogen
C) CO2
What stage is NOT part of the basic EtO sterilization cycle?
A) Preconditioning B) Gas introduction C) Cooling D) Air washes
C) Cooling
What is the purpose of aeration after EtO sterilization?
A) To kill remaining microorganisms B) To remove noxious EtO residues C) To dry sterilized materials D) To prevent corrosion
B) To remove noxious EtO residues
What effect does residual moisture in needles and tubing have on EtO sterilization?
A) Enhances sterilization B) Prevents sterilization C) Reduces sterilization efficacy D) Has no effect
C) Reduces sterilization efficacy
What is the typical duration of mechanical aeration after EtO sterilization?
A) 2-4 hours B) 8-12 hours C) 24 hours D) 48 hours
B) 8-12 hours
How long should EtO-sterilized implants be aerated in ambient room conditions?
A) 2 days B) 7 days C) 10 days D) 2 weeks
D) 2 weeks
Which of the following instruments is unsuitable for gas plasma sterilization?
A) Rigid endoscopy lenses B) Insulated electrosurgery instruments C) Flexible endoscopes D) Metal instruments
C) Flexible endoscopes
What phase is unnecessary in hydrogen peroxide gas plasma sterilization?
A) Preconditioning B) Gas introduction C) Aeration D) Drying
C) Aeration
Why must items be fully dry before hydrogen peroxide gas plasma sterilization?
A) Moisture can dilute hydrogen peroxide B) Moisture inhibits vacuum formation C) Moisture promotes microbial growth D) Moisture is unnecessary
B) Moisture inhibits vacuum formation
What is a potential drawback of using hydrogen peroxide gas plasma sterilization?
A) It dulls surgical instruments B) It creates toxic residues C) It is unsuitable for very long narrow lumens D) It requires extended drying times
C) It is unsuitable for very long narrow lumens
Which disinfectant is most commonly used for high-level disinfection of endoscopes?
A) Formaldehyde B) Glutaraldehyde C) Hydrogen peroxide D) Ethylene oxide
B) Glutaraldehyde
Which compound is used to neutralize glutaraldehyde before disposal?
A) Sodium bisulfate B) Peracetic acid C) Hydrogen peroxide D) Ethylene oxide
A) Sodium bisulfate
Which pH range maximizes glutaraldehyde activity?
A) 3-4 B) 5-6 C) 7.5-8.5 D) 9-10
C) 7.5-8.5
What is a common adverse effect of glutaraldehyde exposure for healthcare workers?
A) Skin corrosion B) Cancer C) Respiratory irritation D) Memory loss
C) Respiratory irritation
Ortho-phthalaldehyde (OPA) has an advantage over glutaraldehyde because it:
A) Requires no activation B) Has a longer shelf life C) Produces no fumes D) All of the above
D) All of the above
What is a potential risk when using ortho-phthalaldehyde?
A) It may cause corrosion of metal instruments B) It can cause allergic reactions in urologic patients C) It forms toxic by-products D) It requires prolonged contact times
B) It can cause allergic reactions in urologic patients
Succindialdehyde has excellent compatibility with which type of instruments?
A) Flexible endoscopes B) Metal implants C) Single-use plastics D) Wooden instruments
A) Flexible endoscopes
What limits the use of formaldehyde in healthcare settings?
A) Its slow activity B) Its cost C) Its carcinogenic side effects and odor D) Its limited effectiveness
C) Its carcinogenic side effects and odor
Which chemical is safer for the environment and less toxic to staff than glutaraldehyde?
A) Peracetic acid (PAA) B) Formaldehyde C) Ethylene oxide D) Ortho-phthalaldehyde
A) Peracetic acid (PAA)
Peracetic acid is typically used in which form?
A) Gas B) Liquid C) Solid D) Powder
B) Liquid
Hydrogen peroxide sterilization primarily kills microorganisms by:
A) Alkylation B) Protein denaturation C) Oxidizing cell components D) Free radical formation
C) Oxidizing cell components
The presence of which enzyme can protect bacteria against hydrogen peroxide sterilization?
A) Protease B) Catalase C) Amylase D) Lipase
B) Catalase
What concentration of hydrogen peroxide is generally required for effective sterilization?
A) 0.5-1% B) 1-3% C) 7.5-25% D) 30-50%
D) 30-50%
What happens if instruments are not properly dried before sterilization in a gas plasma system?
A) They remain unsterilized B) They corrode C) They remain damp D) They become deformed
A) They remain unsterilized
What is the typical duration of a hydrogen peroxide gas plasma sterilization cycle?
A) 30-75 minutes B) 2-4 hours C) 5-10 hours D) 24 hours
A) 30-75 minutes
For what reason might high levels of humidity affect the efficacy of LTS methods like hydrogen peroxide?
A) Hydrogen peroxide decomposes in moisture B) High humidity prevents plasma formation C) High humidity causes instrument corrosion D) High humidity does not affect sterilization
A) Hydrogen peroxide decomposes in moisture
How does UV light contribute to sterilization processes?
A) By dehydrating microbes B) By causing DNA damage in microorganisms C) By denaturing proteins D) By creating free radicals
B) By causing DNA damage in microorganisms
Which of the following characteristics is shared by both VHP and HPV systems?
A) They both work by creating microcondensation B) They both reduce relative humidity C) They both prevent surface condensation D) They both use vaporized hydrogen peroxide
D) They both use vaporized hydrogen peroxide
Electrolyzed strong acid water (EAW) has a pH of less than ___.
A) 7 B) 6 C) 5 D) 3
D) 3
The bactericidal effect of EAW is due to the formation of ____ during electrolysis.
A) Hydroxy radicals B) Chlorine dioxide C) Sodium hypochlorite D) Hypochlorous acid
A) Hydroxy radicals
What happens to EAW’s bactericidal effect in the presence of organic matter or biofilm?
A) It is enhanced B) It remains the same C) It drastically decreases D) It becomes toxic
C) It drastically decreases
What property makes hypochlorites commonly used as disinfectants?
A) They are slow-acting B) They have a broad spectrum of antimicrobial activity C) They leave toxic residues D) They are unaffected by organic matter
B) They have a broad spectrum of antimicrobial activity
Hypochlorous acid (HOCl) is primarily effective in which pH range?
A) Low pH B) High pH C) Neutral pH D) Any pH
A) Low pH
Why is chlorine dioxide not suitable for use on flexible endoscopes?
A) It discolors the casing B) It does not kill viruses C) It has no residual effect D) It is not broad-spectrum
A) It discolors the casing
What is the major component of Virkon peroxygenic acid?
A) Potassium monoperoxysulfate B) Sodium hypochlorite C) Chlorine dioxide D) Peracetic acid
A) Potassium monoperoxysulfate
Why is Virkon considered unsuitable for disinfecting medical devices?
A) It forms toxic by-products B) It does not kill endospores within a practical time C) It is expensive D) It evaporates too quickly
B) It does not kill endospores within a practical time
Alcohols are ineffective in the presence of which of the following?
A) Organic debris B) Fungi C) Moist surfaces D) Detergents
A) Organic debris
What is the optimal concentration range of alcohol for its maximal antimicrobial effect?
A) 30%-50% B) 50%-70% C) 60%-90% D) 90%-100%
C) 60%-90%
Which alcohol has the strongest bactericidal efficacy?
A) Ethanol B) Isopropanol C) n-Propanol D) Methanol
C) n-Propanol
90-second 70% isopropyl alcohol scrub (IPA)
winner
Ethanol is most effective against which type of pathogens?
A) Bacterial spores B) Enveloped viruses C) Mycobacteria D) Yeasts
B) Enveloped viruses
Chlorhexidine gluconate is typically used in which concentration range for skin antisepsis?
A) 0.5%-0.75% B) 1%-2% C) 2%-4% D) 5%-7%
C) 2%-4%
What is the primary mechanism of action of chlorhexidine (CHX) on bacteria?
A) Disruption of bacterial protein synthesis B) Inhibition of DNA replication C) Damage to the cytoplasmic membrane D) Destruction of bacterial cell wall
C) Damage to the cytoplasmic membrane
CHX is reported to have limited effectiveness against which of the following?
A) Gram-negative bacteria B) Gram-positive bacteria C) Methicillin-resistant S. aureus (MRSA) D) Mycobacteria
C) Methicillin-resistant S. aureus (MRSA)
CHX efficacy is reduced in the presence of which material?
A) Chlorine dioxide B) Organic matter C) Hypochlorous acid D) Alcohols
B) Organic matter
In which type of solution is ethanol less effective for sterilization?
A) 100% ethanol solution B) 60%-90% ethanol in water C) 70%-90% ethanol in saline D) 50%-60% ethanol solution
A) 100% ethanol solution
Which disinfectant can inactivate bacterial spores within a practical timeframe?
A) Chlorhexidine B) Alcohols C) Peracetic acid D) Hypochlorous acid
C) Peracetic acid
What makes peracetic acid superior for sterilizing heat-sensitive instruments?
A) It is non-corrosive B) It works at room temperature C) It leaves no toxic residues D) It enhances metal instruments
B) It works at room temperature
Alcohol-based hand rubs are typically most effective when containing:
A) 40%-60% alcohol B) 60%-95% alcohol C) 95%-100% alcohol D) 100% alcohol
B) 60%-95% alcohol
Which disinfectant is reported to lose effectiveness in direct sunlight?
A) Hypochlorous acid B) Isopropanol C) Chlorhexidine D) Peracetic acid
A) Hypochlorous acid
The primary mode of action of alcohols against bacteria is:
A) Disruption of DNA B) Denaturation of proteins C) Oxidation of cell walls D) Chelation of metals
B) Denaturation of proteins
What is the primary mode of action of inorganic iodine?
A) Disrupts DNA B) Alters the cytoplasmic membrane C) Penetrates the cell wall and disrupts protein and nucleic acids D) Inhibits RNA synthesis
C) Penetrates the cell wall and disrupts protein and nucleic acids
Why is resistance development against elemental iodine considered unlikely?
A) It is highly concentrated B) It binds irreversibly to microbial proteins C) Its rapid action prevents adaptive resistance D) It accumulates inside bacterial cells
C) Its rapid action prevents adaptive resistance
Which of the following is NOT a disadvantage of using iodine in its elemental form?
A) Tissue irritation B) Staining C) Rapid degradation in organic matter D) Radiopacity
C) Rapid degradation in organic matter
What is the primary function of the polyvinylpyrrolidone (PVP) carrier in iodophors like Betadine?
A) Enhances staining of tissues B) Reduces iodine's corrosiveness C) Reduces iodine's antimicrobial spectrum D) Enhances tissue penetration
B) Reduces iodine’s corrosiveness
What happens when a 10% PVP-I2 solution is diluted?
A) Free iodine is neutralized B) More free iodine is released C) Iodine binds more strongly to PVP D) The bactericidal activity is reduced
B) More free iodine is released
What is the minimum contact time required for PVP-I2 to release free iodine?
A) 30 seconds B) 2 minutes C) 5 minutes D) 15 minutes
B) 2 minutes
Which solution is considered more effective against spores?
A) PVP-I2 in water B) PVP-I2 in alcohol C) Iodine tinctures D) Chlorhexidine in alcohol
A) PVP-I2 in water
What is a noted benefit of PVP-I2 as an ophthalmic solution?
A) Higher bactericidal activity at 10% concentration B) Effective against fungal infections C) Cornea-friendly properties D) Superior spore-killing ability
C) Cornea-friendly properties
Why is PVP-I2 not recommended for lavage of the peritoneal cavity in horses?
A) It induces metabolic acidosis B) It causes tissue necrosis C) It binds poorly to organic material D) It has no bactericidal effect in this area
A) It induces metabolic acidosis
Which antiseptic agent is effective against both MRSA and gram-negative bacteria in body washes?
A) Chlorhexidine B) Octenidine C) PVP-I2 D) Benzalkonium chloride
B) Octenidine
What microbial population was least susceptible to octenidine in studies?
A) Staphylococcus epidermidis B) Escherichia coli C) Candida albicans D) Pseudomonas aeruginosa
B) Escherichia coli
What distinguishes octenidine from CHX in terms of microbial action?
A) Octenidine is less effective against gram-positive bacteria B) Octenidine does not harm human tissues C) CHX is more effective at low concentrations D) CHX acts faster
B) Octenidine does not harm human tissues
Quaternary ammonium compounds are ineffective against which of the following?
A) Gram-negative bacteria B) Viruses C) Gram-positive bacteria D) Lipid-based microbes
B) Viruses
Which of the following antiseptics is used in contact lens solutions?
A) Phenol B) Polyhexamethylene biguanide (PHMB) C) Quaternary ammonium compounds D) Octenidine
B) Polyhexamethylene biguanide (PHMB)
What is the primary advantage of PHMB over saline in wound care?
A) Higher cytotoxicity B) Faster antimicrobial action C) Better tissue compatibility D) Reduced residual activity
C) Better tissue compatibility
What mechanism limits the combination of CHX and PVP-I2 in antiseptic solutions?
A) CHX neutralizes iodine B) Both agents amplify each other’s toxicity C) They form an insoluble compound D) They have overlapping microbial targets
A) CHX neutralizes iodine
Why should diluted antiseptic solutions like iodine be discouraged for sinus lavages?
A) They promote resistance development B) They cause tissue necrosis C) They are inactivated by organic material D) They do not kill fungi effectively
A) They promote resistance development
Which of the following microorganisms shows the greatest susceptibility to octenidine?
A) Staphylococcus epidermidis B) Escherichia coli C) Pseudomonas aeruginosa D) Candida albicans
A) Staphylococcus epidermidis
Why is PVP-I2 considered cornea-friendly?
A) It is less acidic than other iodine preparations B) It is less irritating at high concentrations C) It causes less staining on the cornea D) It releases iodine slowly to minimize toxicity
D) It releases iodine slowly to minimize toxicity
What class of chemicals does octenidine belong to?
A) Bisphenols B) Biguanides C) Quaternary ammonium compounds D) Bispyridines
D) Bispyridines
What is the key reason that sequential use of CHX and PVP-I2 can be more effective than using either agent alone?
A) It avoids neutralization of each agent B) They act on different microbial targets C) Synergistic effect against S. aureus D) Increased tissue penetration
C) Synergistic effect against S. aureus
Why is CHX resistance considered rare in gram-positive bacteria?
A) Gram-positive bacteria lack efflux mechanisms B) CHX forms stronger bonds with gram-positive cell walls C) CHX’s concentration in hospitals is generally low D) Gram-positive bacteria have less envelope permeability
D) Gram-positive bacteria have less envelope permeability
Which of the following antiseptics has an anti-inflammatory effect in wound care?
A) Octenidine B) PHMB C) PVP-I2 D) Benzalkonium chloride
B) PHMB
Which antiseptic has its bactericidal activity significantly enhanced by alcohol?
A) PHMB B) CHX C) PVP-I2 D) Octenidine
B) CHX
