11. Sterilization

Question 1

What is the goal of sterilization?

Answer 1

To destroy all microorganisms including bacteria, viruses, spores, fungi, and prions on or in an object.

Question 2

What are the two main types of sterilization?

Answer 2

Chemical and physical.

Question 3

What does SAL stand for?

Answer 3

Sterility Assurance Level.

Question 4

What does SAL measure?

Answer 4

The probability of a single viable microorganism occurring on a product after sterilization.

Question 5

What are critical items in sterilization?

Answer 5

Items that contact sterile tissues or the bloodstream and must be sterilized.

Question 6

Give examples of critical items.

Answer 6

Surgical instruments, catheters, needles, implants.

Question 7

What are semicritical items?

Answer 7

Items that contact mucous membranes or nonintact skin and should be sterilized.

Question 8

Give examples of semicritical items.

Answer 8

Endotracheal tubes, laryngoscopes, esophageal probes.

Question 9

What are noncritical items?

Answer 9

Items that contact only intact skin and can be disinfected.

Question 10

Give examples of noncritical items.

Answer 10

Stethoscopes, blood pressure cuffs, gurneys.

Question 11

Why is early cleaning of surgical instruments important?

Answer 11

To prevent drying of debris and facilitate effective sterilization.

Question 12

What can cause corrosion of surgical instruments?

Answer 12

Blood, body fluids, and saline.

Question 13

What is toxic anterior segment syndrome (TASS)?

Answer 13

A severe inflammatory process in the anterior chamber post-ophthalmic procedures due to instrument contamination.

Question 14

What is cavitation in ultrasonic cleaning?

Answer 14

Implosion of gas bubbles created by ultrasonic waves to remove debris.

Question 15

What do washer sterilizers do?

Answer 15

Use steam and detergent to clean instruments.

Question 16

What is the purpose of wrapping materials?

Answer 16

To prevent microbial penetration and allow sterilant access.

Question 17

What should wrapping materials be resistant to?

Answer 17

Heat, physical damage, and moisture.

Question 18

Why use double-layer wrapping?

Answer 18

For longer storage times and reduced contamination.

Question 19

What are the most common steam sterilization wrapping materials?

Answer 19

Cotton muslin, nonwoven paper, polypropylene fabric, plastic pouches.

Question 20

Which materials can’t be used with hydrogen peroxide sterilization?

Answer 20

Linens and paper.

Question 21

Why should hinged instruments be opened during sterilization?

Answer 21

To maximize sterilant contact.

Question 22

What are liquid chemical sterilants also called?

Answer 22

Cold sterilization.

Question 23

Why is cold sterilization not recommended for surgical instruments?

Answer 23

Due to lack of biologic indicators and risk of contamination.

Question 24

What is glutaraldehyde used for?

Answer 24

Chemical sterilization, effective with prolonged exposure.

Question 25

What is a disadvantage of glutaraldehyde?

Answer 25

It is irritating and has a short shelf-life.

Question 26

What is a benefit of ortho-phthalaldehyde over glutaraldehyde?

Answer 26

Less irritating and more effective without pH adjustment.

Question 27

Why is formaldehyde not widely used?

Answer 27

It is carcinogenic and less effective.

Question 28

What does hydrogen peroxide do in sterilization?

Answer 28

Produces free radicals to destroy microbes.

Question 29

What is the role of peracetic acid?

Answer 29

Acts as an oxidizing sterilant with good efficacy.

Question 30

What is a benefit of steam sterilization?

Answer 30

Inexpensive, non-toxic, effective against spores.

Question 31

How does steam sterilization work?

Answer 31

Kills microorganisms by denaturing proteins using moist heat.

Question 32

What temperature and time are needed for gravity-displacement autoclaves?

Answer 32

121°C for 30 min or 132°C for 15 min.

Question 33

What is flash sterilization?

Answer 33

High-temp, short-time sterilization for unwrapped items.

Question 34

What is ethylene oxide sterilization used for?

Answer 34

Sterilizing heat-sensitive items.

Question 35

Why is ethylene oxide mixed with CO2 or HCFC?

Answer 35

To reduce flammability.

Question 36

What are safety concerns with ethylene oxide?

Answer 36

It is carcinogenic, mutagenic, and neurotoxic.

Question 37

How does ozone sterilization work?

Answer 37

Oxidizes cell components using ozone gas.

Question 38

What is a benefit of ozone sterilization?

Answer 38

No toxic residue and safe for operators.

Question 39

What is plasma sterilization?

Answer 39

Uses ionized gas to destroy microorganisms.

Question 40

What is a limitation of plasma sterilization?

Answer 40

Not suitable for linens, liquids, or wood.

Question 41

What is vaporized hydrogen peroxide sterilization?

Answer 41

Low-temp, rapid sterilization with no toxic residue.

Question 42

What is radiation sterilization used for?

Answer 42

Sterilizing sutures, implants, and some biologics.

Question 43

What organism is used in steam sterilization biological indicators?

Answer 43

Geobacillus stearothermophilus.

Question 44

What organism is used in ethylene oxide biological indicators?

Answer 44

Bacillus atrophaeus.

Question 45

What are physical indicators?

Answer 45

Graphs or printouts confirming time and temperature.

Question 46

What does a Class 1 chemical indicator do?

Answer 46

Indicates exposure to sterilization but not effectiveness.

Question 47

What is a Bowie-Dick test?

Answer 47

A Class 2 indicator testing air removal in pre-vacuum autoclaves.

Question 48

What is the best method to confirm sterilization?

Answer 48

Biologic indicators.

Question 49

How should sterilized items be stored?

Answer 49

Dry, dust-free, temp <24°C, humidity <70%, in closed cabinets.

Question 50

How long can steam-sterilized packs be stored in double-wrap?

Answer 50

Up to 96 weeks.

Question 51

How should sterilized packs be labeled?

Answer 51

Contents, date, expiration, and preparer's initials.