Chapter 12 Sterilization

Question 1

a. _________ is the process of destroying all microorganisms (including bacteria, viruses, spores, fungi, and prions) on or in an object. i. Can occur through chemical or physical means with varying advantages and disadvantages involving speed, efficacy, dangers, and expenses.

Answer 1

Sterilization

Question 2

_______is anything less than sterilization i. High-level disinfectants are those that kill any microorganisms present with the exception ii. Intermediate level disinfectants will not kill bacterial spores iii. Low level disinfectants will kill most vegetative bacteria, as well as some fungi and viruses

Answer 2

Disinfection

Question 3

Spalding classification of equipment i. Critical – ii. Semi-critical – iii. Noncritical –

Answer 3

Spalding classification of equipment i. Critical – those items associated with a high risk of infection if they become contaminated. (surgical instruments, catheters, needles, and implants) which should all be sterilized. ii. Semi-critical – those that come into contact with mucous membranes or skin such a laryngoscopes and esophageal probes. These items should be subjected to sterilization or high-level disinfection iii. Noncritical – those items that contact only skin, such as stethoscopes and gurneys. These can be disinfected with low-level disinfectants

Question 4

An initial pretreatment soak in___ ____or rinse under cool running water may be helpful (as dried debris may allow transmission of infectious organisms such as spore forming bacteria, viruses, and prions as it becomes difficult to remove.

Answer 4

cool water

Question 5

_____ ______ of surgical instruments a. _____ _____ is preferable for delicate or detailed instruments and for instruments that are heat or moisture sensitive but may be inferior to some mechanical cleaning devices for general instruments b. Enzymatic cleaners or detergents that are compatible with the material and design of the instruments may help to loosen blood, tissue, and gross debris. c. May be costly, time consuming, and result in exposure to chemicals

Answer 5

III. Manual cleaning of surgical instruments a. Manual cleaning is preferable for delicate or detailed instruments and for instruments that are heat or moisture sensitive but may be inferior to some mechanical cleaning devices for general instruments b. Enzymatic cleaners or detergents that are compatible with the material and design of the instruments may help to loosen blood, tissue, and gross debris. c. May be costly, time consuming, and result in exposure to chemicals

Question 6

______ cleaning of surgical instruments i. Includes the use of ultrasonic cleaning devices, washer decontaminators/disinfectors, or washer sterilizers. ______ cleaning is the preferred method of cleaning as it facilitates washing and rinsing without the risks of manual cleaning and efficiently removes soil and debris.

Answer 6

IV. Mechanical cleaning of surgical instruments i. Includes the use of ultrasonic cleaning devices, washer decontaminators/disinfectors, or washer sterilizers. ii. Mechanical cleaning is the preferred method of cleaning as it facilitates washing and rinsing without the risks of manual cleaning and efficiently removes soil and debris.

Question 7

_______cleaning devices utilize the process of cavitation, whereby ultrasonic waves are used to create minute gas bubbles which then implode creating a minute vacuum that facilitates the removal of particles and debris. _________decontaminators/disinfectors use a combination of circulating water and detergents to facilitate the cleaning process. _____ sterilizers are modified steam autoclaves that bubble steam through water and detergent to accomplish the cleaning. Instruments should be thoroughly rinsed before sterilization as chemical residues could affect the sterilization process or result in harm to the patient or the hospital personnel.

Answer 7

iii. Ultrasonic cleaning devices utilize the process of cavitation, whereby ultrasonic waves are used to create minute gas bubbles which then implode creating a minute vacuum that facilitates the removal of particles and debris. iv. Washer decontaminators/disinfectors use a combination of circulating water and detergents to facilitate the cleaning process. v. Washer sterilizers are modified steam autoclaves that bubble steam through water and detergent to accomplish the cleaning. 1. Instruments should be thoroughly rinsed before sterilization as chemical residues could affect the sterilization process or result in harm to the patient or the hospital personnel.

Question 8

The only approved method for drying instruments is the use of medical-grade _____ ___.

Answer 8

a. The only approved method for drying instruments is the use of medical-grade compressed air.

Question 9

The ideal packaging material is resistant to penetration, allows ready passage of the sterilizating agent, allows for ________(in the case of ethylene oxide), prevents _________penetration, and resists _______penetration. It should be easy to work with and should be transparent and economical.

Answer 9

e. The ideal packaging material is resistant to penetration, allows ready passage of the sterilizating agent, allows for aeration (in the case of ethylene oxide), prevents microbial penetration, and resists moisture penetration. It should be easy to work with and should be transparent and economical.

Question 10

Instruments with hinges should be _______to maximize the surface area accessible to the sterilizing agent and packs should not be overfilled for the same reason

Answer 10

f. Instruments with hinges should be opened to maximize the surface area accessible to the sterilizing agent and packs should not be overfilled for the same reason

Question 11

_____ chemical germicides (____sterilization) i. The process of soaking instruments or other equipment in a disinfectant (frequently a liquid) to achieve acceptable reductions in microbial presence. ii. These products have a decreased ability to access microbes in the interiors or crevices of items when compared with thermal methods of sterility. iii. Must be washed with sterile water

Answer 11

a. Liquid chemical germicides (cold sterilization) i. The process of soaking instruments or other equipment in a disinfectant (frequently a liquid) to achieve acceptable reductions in microbial presence. ii. These products have a decreased ability to access microbes in the interiors or crevices of items when compared with thermal methods of sterility. iii. Must be washed with sterile water

Question 12

______has reasonable efficacy against bacterial spores, but only with prolonged exposure. i. Acidic in aqueous solution and must be alkalinated to boost its efficacy. ii. Shelf-life of 14 days iii. Irritating to the respiratory passages and can even decrease pulmonary function iv. High-level disinfectant but is too expensive to be used on noncritical items

Answer 12

b. Glutaraldehyde has reasonable efficacy against bacterial spores, but only with prolonged exposure. i. Acidic in aqueous solution and must be alkalinated to boost its efficacy. ii. Shelf-life of 14 days iii. Irritating to the respiratory passages and can even decrease pulmonary function iv. High-level disinfectant but is too expensive to be used on noncritical items

Question 13

______________ i. Does not require pH changes ii. Is less irritating and more efficacious iii. Can cause skin and tissue staining

Answer 13

c. Ortho-phthaladehyde (OPA/Cidex) i. Does not require pH changes ii. Is less irritating and more efficacious iii. Can cause skin and tissue staining

Question 14

___________ i. 37% aqueous solution (formalin) ii. Carcinogen makes it a poor candidate for most clinical applications

Answer 14

d. Formaldehyde i. 37% aqueous solution (formalin) ii. Carcinogen makes it a poor candidate for most clinical applications

Question 15

_____ _____ i. Chemical sterilant – produces hydroxyl free radicals to interfere with membranes and nucleic acids. ii. Concentrations of 7.5% or greater exceed the efficacy of glutaraldehyde. iii. Toxic to mucous membranes and can discolor some metals.

Answer 15

e. Hydrogen Peroxide i. Chemical sterilant – produces hydroxyl free radicals to interfere with membranes and nucleic acids. ii. Concentrations of 7.5% or greater exceed the efficacy of glutaraldehyde. iii. Toxic to mucous membranes and can discolor some metals.

Question 16

_____ acid i. Has good antimicrobial efficacy ii. Breaks down into environmentally inert products, but is relatively unstable leading to a short useful efficacy (approximately 6 days).

Answer 16

f. Peracetic acid i. Has good antimicrobial efficacy ii. Breaks down into environmentally inert products, but is relatively unstable leading to a short useful efficacy (approximately 6 days).

Question 17

______ _____-and hypochlorites i. Disinfectants ii. At certain concentrations or exposure times, they may reach antimicrobial levels associated with sterility, but their overall efficacy or undersirable properties make them poor candidates for use as a sterilizing agent.

Answer 17

g. Quaternary ammoniums and hypochlorites i. Disinfectants ii. At certain concentrations or exposure times, they may reach antimicrobial levels associated with sterility, but their overall efficacy or undersirable properties make them poor candidates for use as a sterilizing agent.

Question 18

steam sterilization a. Autoclaves will likely remain the most common method of sterilization in veterinary practices for some time and are the preferred method of sterilization for items that are heat stable and moisture stable. b. Kills microorganisms through _____and _____of proteins by moist heat. c. Water serves as a _____to the chemical reactions involved in destruction of proteins, thereby hastening the process and allowing lower temperatures to be used. d. Heat is transferred from the steam by the process of _____, not merely by heat absorption as would be the case with dry heat. e. Inexpensive, efficacious (including against spores), nontoxic, and rapidly effective with a variety of materials. f. Operate under a balance of steam, pressure, temperature, and time. g. Typical temperatures may be 121 degree C (250 degree F) for _____minutes in a gravity-displacement sterilizer, or 132 degrees C (270 degrees F) for _____minutes in a prevacuum unit.

Answer 18

a. Autoclaves will likely remain the most common method of sterilization in veterinary practices for some time and are the preferred method of sterilization for items that are heat stable and moisture stable. b. Kills microorganisms through coagulation and denaturation of proteins by moist heat. c. Water serves as a catalyst to the chemical reactions involved in destruction of proteins, thereby hastening the process and allowing lower temperatures to be used. d. Heat is transferred from the steam by the process of condensation, not merely by heat absorption as would be the case with dry heat. e. Inexpensive, efficacious (including against spores), nontoxic, and rapidly effective with a variety of materials. f. Operate under a balance of steam, pressure, temperature, and time. g. Typical temperatures may be 121 degree C (250 degree F) for 30 minutes in a gravity-displacement sterilizer, or 132 degrees C (270 degrees F) for 4 minutes in a prevacuum unit.

Question 19

h. Gravity-displacement sterilizer is the most common type of autoclave used in veterinary practice i. Items sterilized at 121 degrees C should have ____minutes of exposure time and ____minutes of drying time. ii. Items sterilized at 132 degrees C should have ____minutes of exposure time and ____minutes of drying time.

Answer 19

h. Gravity-displacement sterilizer is the most common type of autoclave used in veterinary practice i. Items sterilized at 121 degrees C should have 30 minutes of exposure time and 15-30 minutes of drying time. ii. Items sterilized at 132 degrees C should have 15 minutes of exposure time and 15-30 minutes of drying time.

Question 20

_______type of unit – functions similarly to the gravity displacement types with the exception that a pump is used to remove air before the steam is admitted. This allows for very rapid and uniform steam distribution within the chamber

Answer 20

i. Prevacuum type of unit – functions similarly to the gravity displacement types with the exception that a pump is used to remove air before the steam is admitted. This allows for very rapid and uniform steam distribution within the chamber

Question 21

Low-temperatures steam sterilization involves the introduction of _____vapor and saturated _____into a prevaccum chamber i. Temperature is maintained between 65-80 degrees C (149-176 degrees F) before the system is purged with air.

Answer 21

j. Low-temperatures steam sterilization involves the introduction of formaldehyde vapor and saturated steam into a prevaccum chamber i. Temperature is maintained between 65-80 degrees C (149-176 degrees F) before the system is purged with air.

Question 22

________ heat i. Less effective than moist heat at a given temperature and must occur at higher temperatures and longer times. ii. 160 degrees C (320 degrees F) for 120 minutes is typical. iii. Some units use forced-air movement to speed the uniform rise of temperature within the chamber

Answer 22

k. Dry heat i. Less effective than moist heat at a given temperature and must occur at higher temperatures and longer times. ii. 160 degrees C (320 degrees F) for 120 minutes is typical. iii. Some units use forced-air movement to speed the uniform rise of temperature within the chamber

Question 23

____ sterilization i. The process of rapidly sterilizing items that are needed for immediate use and therefore cannot be subjected to the normal protocol of the institution. ii. Steam autoclave iii. Gravity displacement autoclave 135 degress C (275 degrees F) for 3 minutes with 1 minute of drying time.

Answer 23

l. Flash sterilization i. The process of rapidly sterilizing items that are needed for immediate use and therefore cannot be subjected to the normal protocol of the institution. ii. Steam autoclave iii. Gravity displacement autoclave 135 degress C (275 degrees F) for 3 minutes with 1 minute of drying time.

Question 24

_______ ____sterilization a. Low temperature method of sterilization b. Colorless and odorless. Flammable c. Alkylation of proteins and nucleic acids, obstructs cell metabolism and reproduction. d. Used for instruments that cannot be steam sterilized. Glass will resist penetration of ____. Can be absorbed to many substances (rubber and some plastics) e. _____is toxic and a carcinogen, mutagen, and neurologic hazard.

Answer 24

VIII. Etyhylene oxide sterilization a. Low temperature method of sterilization b. Colorless and odorless. Flammable c. Alkylation of proteins and nucleic acids, obstructs cell metabolism and reproduction. d. Used for instruments that cannot be steam sterilized. Glass will resist penetration of EtO. Can be absorbed to many substances (rubber and some plastics) e. EtO is toxic and a carcinogen, mutagen, and neurologic hazard.

Question 25

Sterilization by _____ a. _____irradiation is also used to sterilize surgical items. b. Used for suture and certain implants c. Potential for oxidative damage to polyethylene implants that are exposed to gamma sterilization and then are stored for prolong periods. d. Certain biologicals (bone graft) may be weakened by irradiation and some pharmaceuticals can be damaged.

Answer 25

XI. Sterilization by radiation a. Gamma irradiation is also used to sterilize surgical items. b. Used for suture and certain implants c. Potential for oxidative damage to polyethylene implants that are exposed to gamma sterilization and then are stored for prolong periods. d. Certain biologicals (bone graft) may be weakened by irradiation and some pharmaceuticals can be damaged.

Question 26

____monitors are associated with the specific sterilization unit that is being use and may include automatic printouts or graphs verifying the time and temperature achieved

Answer 26

a. Physical monitors are associated with the specific sterilization unit that is being use and may include automatic printouts or graphs verifying the time and temperature achieved

Question 27

______monitors react to specific parameters that are critical to the sterilization process, typically by a color change. They confirm that conditions for sterilization have been met, but do not guarantee that the contents of a pack are truly sterilized. i. Class 1 indicator (sterilization tape) indicates that the pack has been processed but provides limited concrete information about the parameters that have been met. ii. Class 2 indicator test for air removal and are known as Bowie-Dick tests iii. Class 3 indicators react to specific parameters such as temperature or time iv. Class 4 indicators react to more than one parameter v. Class 5 indicator react to all the parameters that are important to a given type of sterilization vi. Class 6 indicators monitor more specific guidelines associated with a unique indication such as the parameters required to combat prion infection, or those associated with particular instruments. 1. A class ____indicator should be placed on the outside of every pack and a class ____indicator should be placed in the deepest portion of the pack.

Answer 27

b. Chemical monitors react to specific parameters that are critical to the sterilization process, typically by a color change. They confirm that conditions for sterilization have been met, but do not guarantee that the contents of a pack are truly sterilized. i. Class 1 indicator (sterilization tape) indicates that the pack has been processed but provides limited concrete information about the parameters that have been met. ii. Class 2 indicator test for air removal and are known as Bowie-Dick tests iii. Class 3 indicators react to specific parameters such as temperature or time iv. Class 4 indicators react to more than one parameter v. Class 5 indicator react to all the parameters that are important to a given type of sterilization vi. Class 6 indicators monitor more specific guidelines associated with a unique indication such as the parameters required to combat prion infection, or those associated with particular instruments. 1. A class 1 indicator should be placed on the outside of every pack and a class 5 indicator should be placed in the deepest portion of the pack.

Question 28

_______ indicators are the best method of determining if the sterilization protocol being followed is effective. i. Consist of a _______of microorganisms that is evaluated post processing to determine viability. ii. One study found a 12% failure rate on sterilization, no instance of which was detected by simultaneous chemical indicators. iii. Rapid action indicators can be evaluated in 1 hour.

Answer 28

c. Biologic indicators are the best method of determining if the sterilization protocol being followed is effective. i. Consist of a culture of microorganisms that is evaluated post processing to determine viability. ii. One study found a 12% failure rate on sterilization, no instance of which was detected by simultaneous chemical indicators. iii. Rapid action indicators can be evaluated in 1 hour.

Question 29

what are the storage times for sterile dressings?

Answer 29