Lecture 3

Question 1

Basic principles of aseptic technique

Answer 1

1. Prevent contamination of open wound
2. isolate the operative site from the surrounding unsterile physical environment
3. create a sterile field in which surgery may be safely performed

Question 2

Bacterial contamination can be minimized by preparing what 4 things?

Answer 2

operating room
operating team
patient surgery site
instrumentation

Question 3

Sterilization

Answer 3

Destruction of ALL living organisms

Question 4

Disinfectant

Answer 4

antibacterial chemical used on inanimate objects

Question 5

3 rules to surgical instrument sterilization

Answer 5

destroy all microbial life
no toxic residue
no instrument damage

Question 6

Methods of sterilization and disinfection are divided into what 2 groups and which is more reliable

Answer 6

Chemical and Physical (more reliable)

Question 7

3 general types of physical sterilization used for medical and surgical materials

Answer 7

1. Filtration
2. Radiation
3. Heat

Question 8

Filtration

Answer 8

separation of particulate matter from liquids/gases

one of the primary ways to sterilize liquids

Question 9

Radiation

Answer 9

• -used primarily for materials that can’t be sterilized by heat or chemicals
• • produces lethal ionization w/o elevation of temperature
• • preferred method for sterilizing commercially pre-packaged stuff
• • Gamma radiation most popular

Question 10

Advantages of wet heat (100% humidity) over dry heat?

Answer 10

• Moisture results in death of the organism at a lower temp in a shorter time
• water is catalyst for coagulation and protein denaturation (faster than oxidation method of dry heat)
• Kill bacterial spores better
• reliable, inexpenxive, non-toxic

Question 11

What is the most dependable method known for the thermal destruction of all microorganisms?

Answer 11

saturated steam under pressure

Question 12

__________ is needed to attain higher temperature of steam. Steam permeates porous substances by________.

Answer 12

Pressure

condensation

Question 13

What is flash autoclaving used for?

Answer 13

emergency sterilization of metal instruments

Do not use for rubber goods or linens!

Question 14

What 2 factors must be attained for appropriate sterilization in the autoclave?

Answer 14

Temperature and duration

Question 15

What is the limiting factor of steam sterilization

Answer 15

bacterial spores (very resistant)

Question 16

The higher the temperature the ________ time the instruments have to cook

Answer 16

less

Question 17

What are the 3 basic types of sterility indicators used to indicate adequate time, pressure, and temperature

Answer 17

Physical, chemical, biological indicators

Question 18

What is the problem with physical indicators

Answer 18

built into the sterilizer/ interior of the surgical pack doesn’t get monitored

Question 19

What is the problem with chemical indicators

Answer 19

paper strips contain a chemical that undergo color change when certain temp is reached but provide no info on amount of exposure time

Question 20

main value of using chemical indicators

Answer 20

tells surgeon pack has been exposed to sterilization process

Question 21

biological indicators

Answer 21

only indicator that truly indicates sterility but is labor intensive, more expensive, and rarely used

Question 22

What should not get autoclaved

Answer 22

plastics
suture material
electronics
powders, glassware, liquid

Question 23

What are the most commonly used chemical sterilization agents and what are they used for

Answer 23

ethylene oxide and Plasma (h202)

sterilize heat sensitive materials that don’t tolerate temperature and moisture under pressure

Question 24

what is the most popular agent for gaseous sterilization in vet med

Answer 24

ethylene oxide

Question 25

Ethylene oxide

Answer 25

• colorless, odorless, toxic gas –> must aerate objects for hours to days
• explosive
• irritating to skin/MM
• kills all organisms by alkylination
• can manipulate conc., humidity, and temperature to alter sterilization times

Question 26

Advantage/Disadvantage of plasma sterilization

Answer 26

immediate use - doesn’t require aeration

items become moist and very expensive

Question 27

What is cold sterilization

Answer 27

soaking instruments in disinfectant solutions

Question 28

What is the problem with cold sterilization

Answer 28

disinfectants have decreased ability to access microbes in the crevices of instruments / NOT recommended for surgical equipment because not 100% sterile

Question 29

How do alcohols kill bacteria and at what concentration

Answer 29

denature proteins / good bactericidal at 70-80% conc.

Question 30

Chemical that reduces bacterial populations on patient and surgeon

Answer 30

antiseptic

Question 31

T/F All antiseptics are toxic to tissues and must be used at appropriate dilutions

Answer 31

True

Question 32

What are the requirements of antiseptics in addition to antimicrobial activity

Answer 32

non-irritating/non-toxic
retain antimicrobial activity under in vivo conditions
do not become inactivated by organic material

Question 33

Advantages/Disadvantages of Chlorhexidine

Answer 33

Advantages:
Non-irritating, good residual activity, not affected by organic matter, effective against wide range of microbes
Disadvantages:
irritation from chronic exposure, ototoxic, corneal toxicity

Question 34

Advantages/Disadvantages of Iodophores

Answer 34

Cheap, wide range of microbes

dermal irritation, decreased activity in organic matter unreliable residual activity, stains

Question 35

Advantages/Disadvantages of alcohols

Answer 35

Advantages: Rapid acting, cheap, drops bacteria load much lower than chlorhexidine/ iodophore so doesn’t matter it has poor residual activity

Disadvantages: decreased activity in organic matter, poor residual activity, dries out skin, rapid heat dissipation