Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

sterilization techniques > sterilization > Flashcards

sterilization Flashcards

1
Q

Why is it of utmost importance to use good quality water, ideally fully demineralized or  at least softened water when cleaning instruments?

A

 It is therefore of utmost importance to use good quality water, ideally fully demineralized or  at least softened water, because high concentrations of dissolved  particles in the water can induce or facilitate surface pitting,  even in high-quality stainless steel. Also,  experiments have  shown that increasing water hardness reduces the removal of  blood in cold water prewashes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

These  cleaners  use  high-frequency  vibratory  waves    that clean through cavitation. As the vibratory waves propagate through the liquid, this liquid is subjected to alternating  negative and positive pressures as the compression and rarefactions of the sound waves pass. During the phase of negative  pressure, numerous gas bubbles are formed and enlarge in the  liquid. This formation of gaseous cavities in the liquid is called  cavitation.  During the subsequent phase of ultrasonic compression (i.e., phase of positive pressure), the pressure exerted on  the  newly  expanded  gas  bubble  compresses  the  same  until    the bubble collapses on itself, imploding with a consequent  shock  wave  of  energy.

A

Ultrasonic  cleaners  use  high-frequency  vibratory  waves    that clean through cavitation. As the ultrasonic waves propagate through the liquid, this liquid is subjected to alternating  negative and positive pressures as the compression and rarefactions of the sound waves pass. During the phase of negative  pressure, numerous gas bubbles are formed and enlarge in the  liquid. This formation of gaseous cavities in the liquid is called  cavitation.  During the subsequent phase of ultrasonic compression (i.e., phase of positive pressure), the pressure exerted on  the  newly  expanded  gas  bubble  compresses  the  same  until    the bubble collapses on itself, imploding with a consequent  shock  wave  of  energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

 Ultrasonic cleaning times in modern equipment are approximately __ minutes at frequencies of around  ___ khz.

A

 Ultrasonic cleaning times in modern equipment are approximately 3 minutes at frequencies of around  35 khz.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What equipment should not be cleaned ultrasonically?

A

 Camera units, optics, and optic cables  should never be cleaned with this technology.
Minimally invasive surgery instruments, rigid endoscopes,  and  high-frequency  instruments  must  be  disassembled  for  machine processing according to the manufaturer’s instructions,  and only those parts approved by the manufacturer may be  cleaned ultrasonically.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which is a more effective barrier, muslin wraps or pima cotton wraps?

A

Pima cotton wraps are a  more effective barrier  than  muslin because of the smaller pore size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How many times can pima cotton wraps be used/reused?

A

up to 75 times; after which so much fabric  has been lost that no effective barrier against microorganisms  exists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

T/F: Sterilization fleece, an interleaved security product, is the  preferred synthetic wrapping material because of its superior  durability and handling qualities and because its safe storage  time is longer than that of fabrics

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the storage times for sterilized packs (open shelf and closed cabinet) for: Single-wrapped muslin  (2 layers)

A

Open shelf: 2 days

Closed Cabinet: 7 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the storage times for sterilized packs (open shelf and closed cabinet) for: Double-wrapped muslin  (each 2 layers)

A

Open shelf: 3 weeks

Closed Cabinet: 7 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the storage times for sterilized packs (open shelf and closed cabinet) for: Crepe paper  (single-wrapped)

A

Open shelf: 3 weeks

Closed Cabinet: 8 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the storage times for sterilized packs (open shelf and closed cabinet) for: Heat-sealed paper and  transparent plastic  pouches

A

Open shelf: at least 1 year

Closed Cabinet: —

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What type of heat kills by a combination of oxidation and removal of  water?

A

Dry heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What type of heat kills by the coagulation of critical  proteins.

A

Moist heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

T/F: Moist heat sterilization can coagulate and denature  cellular protein at lower temperatures than those required by  dry heat and thus can decrease the temperatures and exposure  times necessary for sterilization

A

True;  Steam gives up its heat to materials  to be sterilized by the process of condensation, and it is able to  penetrate porous substances more rapidly than dry heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the minimum guidelines for exposure time, temperature, and pressure in a steam autoclave?

A

 Minimum guidelines are an exposure time of 15 minutes at 121° C (249.8° F)  and 15 psi or 2 atmospheres of pressure in a steam autoclave. 5-10 min destroys most resistant microbes;  an additional 3-8 min provides a safety  margin. Autoclave at 134° C for 18 min is effective in inactivating prions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the minimum guidelines for exposure time, temperature when Emergency/“flashing” an instrument in perforated metal  trays in a prevacuum autoclave (shorter heat-up times required)

A

3 minutes at 131C (270F)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

This chemical sterilization agent is an alkylating agent that kills microorganisms by inactivation of proteins, DNA, and RNA, and it is effective against  vegetative bacteria, fungi, viruses, and spores. It is supplied as  a gas mixed with a carrier agent (Freon or CO2) to reduce flammability.

A

Ethylene oxide (EO); Mixed with air or oxygen, EO is explosive and flammable.  Carbon  dioxide  is  the  preferred  diluent  because  of  environmental concerns about fluorinated hydrocarbon (Freon)  release, although EO has a tendency to stratify from carbon  dioxide in storage containers, which could affect sterilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Use of ethylene oxide is limited by equipment size, time requirement and toxicity. It is recommended that it be reserved for items unsuitable for steam sterilization (laparoscopes, light cables, and camera heads, etc.). What is a replacement choice for sterilization?

A

Plasma sterilizers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

T/F:  Films of polyethylene, polypropylene, nylon,  and polyvinyl chloride can be used for packaging items for EO sterilization and storage. 

A

False; Because EO penetrates materials more readily than steam, a  wider variety of materials may be used in packaging items for  sterilization and storage. Films of polyethylene, polypropylene,  and polyvinyl chloride are commercially available, but nylon  should not be used, because it is penetrated poorly by EO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

T/F: After sterilization by EO, materials must be aerated to allow  dissipation of the absorbed chemical because residual EO can damage tissues

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

 What is a highly  toxic degradation product of EO that is formed most readily in  products that have been previously sterilized by radiation?  This risk is greatest with polyvinyl chloride products

A

 Ethylene chlorohydrin 

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

This type of sterilization  allows short instrument turnaround time, has no recognized health hazards, and operates at a low temperature (less  than 50° C).

A

Gas plasma sterilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is gas plasma created and how does it sterilize?

A

An aqueous solution of hydrogen peroxide is  injected into the chamber and converted to gas plasma by radio  waves  that  create  an  electrical  field. In  this  field,  hydrogen  peroxide vapor is converted to free radicals that collide with and  inactivate microorganisms

24
Q

T/F: Gas plasma is suitable for heat-  and moisture-sensitive instruments (rigid endoscopy lenses and instrument  sets,  objective  lenses  for  microscopes,  nonfabric  tourniquets,  medication  vials,  insulated  electrosurgery  and  cautery instruments, and metal instruments).

A

True

25
Q

What types of instruments/equipment is unsuitable for gas plasma sterilization and why?

A

Gas  plasma  is  unsuitable  for  flexible  endoscopes,  liquids, and items derived from plant fibers (paper products,  linens, gauze sponges, Q-tip applicators, cast padding, wooden  tongue depressors, gloves, and single-use items), because these  materials absorb hydrogen peroxide and inhibit sterilization.  Very long narrow lumens, lumens closed at one end, folded  plastic bags, and sheeting are unsuitable for sterilization by gas  plasma.

26
Q

Define high-level disinfection

A

 High-level  disinfection refers to the use of a chemical sterilant for exposure  times that are insufficient to achieve sterilization (elimination  of all microorganisms and spores) but sufficient to inactivate all  microorganisms (bacteria, fungi, viruses, and mycobacteria), but not  all  bacterial  spores

27
Q

T/F:   in  typical  use,  high-level  disinfection appears to provide the same efficacy as sterilization

A

True

28
Q

This agent works by protein denaturation; is Bactericidal, effective against  vegetative bacteria only.
Poor against spores, fungi,  viruses
Cytotoxic in tissue

A

Isopropyl alcohol (propanol)

29
Q

This agent works through protein denaturation; it is Bactericidal, fungicidal. Effective against many  important viruses.
Cytotoxic in tissue

A

Propan-2-ol and Propan-1-ol

Sterillium

30
Q

This agent works through protein denaturation; it is Bactericidal (MRSA),  fungicidal, and Effective against many  important viruses.
Cytotoxic in tissues, avoid  contact with the eyes, easily  flammable

A

Ethanol 96% and  Biphenyl-2-ol

Desderman  pure

31
Q

This agent works through protein and nucleic acid  denaturation; it is
Bactericidal, fungicidal,  viricidal, and sporicidal.
Long (10-hr) exposure time  required for sporicidal effect. Limited shelf life once activated. Tissue irritant/toxicity

A

Glutaraldehyde (Cidex, Omnicide, Abcocide)

32
Q

This agent works through cell membrane  disruption and cellular  protein precipitation. It is
Bactericidal, fungicidal;  variable/inconsistent activity against  viruses (and fungi).
Not sporicidal

A

Chlorhexidine (Nolvasan)

33
Q

This agent works through metabolic interference; it is Bactericidal, viricidal, and fungicidal.
Poorly sporicidal. Some inactivation by organic  debris

A

Povidone-iodine (Betadine)

34
Q

T/F: Unlike antiseptics, disinfectants are not intended for use on living tissue and  actually can be harmful to tissues at the concentrations required to achieve full efficacy.

A

True;  In fact, the broader the range of microbes  it  eliminates  and  the  faster  it  acts,  the  more  corrosive  and    toxic it is

35
Q

T/F: Because heat and moisture are damaging to certain instruments,  such as endoscopes, arthroscopes, and laparoscopes, cold disinfection with glutaraldehyde, a saturated dialdehyde (Cidex,  Omnicide 28, Abcocide), can be used for these items.

A

True-ish; Although glutaraldehyde is effective against a wide range of susceptible organisms, Cidex is now classified as a disinfectant by the  manufacturer, rather than as a sterilant, and therefore its use on  arthroscopic  and  laparoscopic  instruments  is  questionable.  Peracetic acid (PAA) would be preferable to sterilize these items

36
Q

This disinfectant  owes  its  biocidal  activity  to  alkylation  of  sulfhydryl,  hydroxyl, carboxyl, and amino groups, which alters microbial  RNA, DNA, and protein synthesis.

A

Glutaraldehyde 

37
Q

Glutaraldehyde’s antimicrobial activity is enhanced in what pH range?

A

 The antimicrobial activity  of glutaraldehyde is greatly enhanced in alkaline solutions (pH  7.5 to 8.5), although high pH hastens its polymerization and  therefore limits its shelf life. To overcome this problem, glutaraldehyde is supplied as an acidic colorless solution that is activated at the time of use by adding an “activator” that converts  it to a green (Cidex, Abcocide) or blue (Omnicide) alkaline  solution with a sharp odor. Acid glutaraldehydes also are  available and do not require activation, but they lack the microbiocidal activity of alkaline preparations

38
Q

T/F: Antimicrobial activity of Cidex increases with increased temperature and decreases with organic matter

A

True

39
Q

This disinfectant is an oxidizing agent  that functions in much the same way as hydrogen peroxide,  through denaturation of protein, disruption of cell wall permeability,  and  oxidation  of  sulfhydryl  and  sulfur  bonds  in proteins, enzymes, and other metabolites.

A

Peracetic acid or peroxyacetic acid (PAA)

40
Q

T/F: Compared with glutaraldehyde, PAA has a similar or  even a better biocidal efficacy and is claimed to be less irritating  for staff and safer for the environment.

A

 True; A contact time of 10 or 15 minutes and  a concentration of greater than 0.09% PAA are recommended  for destruction of bacteria, fungi, viruses, and spores.  PAA does not fix proteins and therefore does not create a biofilm. It has the ability  to remove glutaraldehyde-hardened material from biopsy channels, and its activity is not adversely affected by organic matter

41
Q

This oxidizing agent can be used as    a  high-level  disinfectant.  It  produces  destructive  hydroxyl  radicals that attack membrane lipids, DNA, and other cellular  components when used at recommended concentrations.

A

Hydrogen peroxide

42
Q

What is the fundamental difference between an antiseptic and a disinfectant?

A

Antiseptics are intended for use on living tissue, whereas disinfectants are intended for use on inanimate objects and can harm  tissue. An agent can be an antiseptic at low  concentrations and a disinfectant at higher concentrations.

43
Q

These antiseptic agents are commonly used in veterinary medicine, but they  are effective only against vegetative bacteria.  They have a mild defatting effect but they are inactivated by a  variety  of  organic  debris  and  have  no  residual  activity  after  evaporation.

A

Alcohols

44
Q

T/F:  Alcohols have a higher and more rapid kill rate  than chlorhexidine, and third best is povidone-iodine

A

True

45
Q

T/F:  The  bactericidal efficacy of 2-propanol can be regarded as superior  to that of 1-propanol, and third best is ethanol.

A

False; The  bactericidal efficacy of 1-propanol can be regarded as superior  to that of 2-propanol, and third best is ethanol

46
Q

T/F: isopropyl alcohol rinse can inactivate hexachlorophene-based  preparations

A

True;  Alcohol does not inactivate chlorhexidine gluconate in vitro and has no significant  effect  on  its  protein-binding  property  in vivo.  However,  isopropyl alcohol rinse can inactivate hexachlorophene-based  preparations  (e.g.,  pHisoHex).

47
Q

What percent is chlorhexidine diacetate?

A

2%

48
Q

What percent is chlorhexidine gluconate?

A

4%

49
Q

This antiseptic agent binds to protein of the stratum corneum,  forming  a  persistent  residue  that  can  kill  bacteria  emerging from sebaceous glands, sweat glands, and hair follicles during surgery

A

Chlorhexidine

50
Q

 Although it can be  toxic to fibroblasts in vitro, in vivo lavage with dilute chlorhexidine (____%) is not harmful to wound healing

A

0.05%; However, the  least known bactericidal concentration (0.05%) of chlorhexidine diacetate causes synovial ulceration, inflammation, and  fibrin  accumulation  in  the  tarsocrural  joints  of  horses

51
Q

T/F: Chlorhexidine  (0.02%),  like  1%  povidone-iodine,  promotes  intraabdominal adhesion formation and therefore should not be  used for peritoneal lavage

A

True

52
Q

Chlorhexidine (____%) potentiated with 3.2 mM EDTA and  0.05 mM  Tris  buffer  (hydroxymethylaminomethylamine)  is  90% lethal to Escherichia coli, Staphylococcus aureus, and Streptococcus zooepidemicus  and  is  not  harmful  to  the  synovium  or  articular cartilage of the tarsocrural joints of ponies

A

0.0005%

53
Q

This antiseptic agent has a very broad antimicrobial  spectrum compared with other agents and a very  short kill time at low concentrations, and organisms do not  develop resistance to it

A

Inorganic or elemental iodine 

54
Q

T/F:  At least 2 minutes  of scrubbing is required to release free iodine from povidone-iodine. Addition of detergents, as in surgical scrubs, further  reduces the release of iodine

A

True

55
Q

Concentrations greater than ___% povidone-iodine in vitro can disrupt neutrophil viability and migration

A

0.05%

56
Q

These antiseptic agents  are cationic surfactants that dissolve lipids in bacterial  cell walls and membranes. Drawbacks to the group are ineffectiveness  against  viruses,  spores,  and  fungi;  formation  of  residue layers; and inactivation by common organic debris and  soaps

A

Quaternary  ammonium  compounds,  such  as  benzalkonium  chloride

57
Q

This antiseptic agent  is  used  to  clean  severely  contaminated  wounds, but it is a poor antiseptic and is mainly effective against  spores,  and  concentrations  lower  than  3%  are  damaging  to  tissues.

A

Hydrogen  peroxide 

sterilization techniques (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions