Sterilization Practices Skills Station - kyha.com

Sterilization Practices Skills Station

1. What is sterilization?
Sterilization is the complete elimination or destruction of all forms of microbial life, including
spores, by either physical or chemical processes (in healthcare facilities).

2. What is sterile (aseptic) technique?
Sterile technique is the purposeful prevention of transfer of organisms from one person to the
next or from one body site to another. The goal is to maintain the microbial count at the
irreducible minimum. Aseptic technique involves use of barriers (i.e., sterile gloves, sterile
gowns, masks, and sterile drapes) during the procedure being conducted to prevent transfer of
organisms from the environment to the patient.

3. What are some unsafe sterilization practices associated with transmission of pathogens?
Lack of compliance with established guidelines for sterilization has lead to numerous infections
and outbreaks of infections:

• Lack of or improper meticulous cleaning (either manual cleaning using friction or
mechanical cleaning using ultrasonic cleaners, washer-disinfectors, or washer sterilizers)
prior to sterilization

• Lack of inspection of equipment surfaces for breaks in integrity which would impair
cleaning, disinfection, or sterilization of the item; lack of inspection of the item for
visible contamination after cleaning

• Packaging not compatible with sterilization process or not strong enough to provide a
barrier to moisture and microorganisms

• Not having available or following current manufacturer’s written instructions regarding
sterilizer cycle parameters (e.g. time, temperature, pressure) by the manufacturer of
the instruments, the sterilizer, and the container or wrap used, and that are consistent
with published guidelines by governmental agencies or professional associations

• Not ensuring that the sterilant has contact with contaminated surfaces, (for example,
correct channel irrigators connected to scopes processed in low temperature
sterilization methods such as peracetic acid; items loaded correctly and loosely into
sterile basket or cart so as not to impede the sterilant)

• Improper handling of sterile supplies
• Improper storage of sterile items or protection against compromise (punctures,

bending), dust, moisture, insects, and temperature and humidity extremes
• Inadequate monitoring of sterilization process (mechanical/physical, chemical, and

biological monitors) to ensure effectiveness of the sterilization cycle.

4. How do we know what items need to be sterile?
Years ago, Dr. Earl Spaulding believed that the manner in which an object should be
disinfected/sterilized depended on its intended use and classified items as such:

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• A CRITICAL item which entered normally sterile tissue or the vascular system should be
sterile

• A SEMICRITICAL item that touched mucous membranes or skin that is not intact
required a disinfection process (high-level disinfection [HLD]) that kills all organisms
with the exception of high numbers of bacterial spores

• A NONCRITICAL item that touched only intact skin required low-level disinfection which
kills vegetative bacteria and some fungi and viruses

Table 1 Spaulding Criteria

Item Level of Germicidal Examples Methods

Action Needed

Critical Sterilization -kills all Surgical instruments, Sterilization (see below)
cardiac catheters
microorganisms, implants, etc.

including bacterial

spores

Semi-critical Kills all Respiratory therapy and High level disinfection
anesthesia equipment, GI (see Cleaning and
microorganisms endoscopes, endocavitary Disinfection module)
probes, etc.
except high numbers Bedpans, crutches, bed Low-level disinfection (or
rails, EKG leads, bedside detergent for
of bacterial spores. tables, walls, floors, and housekeeping surfaces) –
furniture. (see Cleaning and
Non-critical Kills vegetative Disinfection module)

bacteria, some fungi

and viruses, but not

mycobacteria and

spores

One can see that as the level of resistance of the organism decreases (Table 2), so does the
method of sterilization or disinfection required. For instance, a high level disinfection would kill
Mycobacterium tuberculosis as well as all other organisms listed beneath M. Tb on the ladder.

Table 2. Decreasing order of resistance of microorganisms to disinfection and sterilization and

the level of disinfection or sterilization:

Organism Level of disinfection or sterilization

Resistance level listed from highest to lowest required

Prions (Creutzfeldt-Jakob Disease) Special sterilization and processing

Bacterial spores (Bacillus atrophaeus) Sterilization

Coccidia (Cryptosporidium) Sterilization

Mycobacteria (M. tuberculosis, M. terrae) High level disinfection

Nonlipid or small viruses (polio, coxsackie) Intermediate level disinfection

Fungi (Aspergillus, Candida) Intermediate level disinfection

Vegetative bacteria (S. aureus, P. aeruginosa) Low level disinfection

Lipid or medium-sized viruses (HIV, herpes, hepatitis B) Low level disinfection

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5. Where should sterilization be performed?
Central Services has responsibility and accountability for reprocessing contaminated equipment
and instruments, especially surgical equipment and instruments. The IP may find that
reprocessing of reusable items occurs outside of Central Processing also (for example, in the
surgical area or patient care area). If this is the case, it is critical to remember that the same
reprocessing standards apply to these areas as well. In addition, all staff handling contaminated
instruments should wear personal protective equipment (PPE).

6. What is the flow of the dirty instrument before sterilization?
Critical point: All items must be properly cleaned in order for disinfection or sterilization to
occur!

• Clean at point of use ASAP; usually involves wiping down with a moist cloth and flushing
lumens with sterile water (no saline)

• Keep instruments moist until cleaned
• Contain and transport to decontamination area
• Ensure staff are properly attired in scrubs and PPE
• Clean dirty item either manually (underwater to minimize splashing, using appropriate

type and amount of detergent, rinsing, and drying) or through use of automation
(ultrasonic cleaning system, washer-sanitizer, etc.)
• All items must be completely disassembled in order to be cleaned and for the sterilant
to have contact with all surfaces.
• Inspect instruments to ensure all soil has been removed in addition to inspection for
proper function and absence of defects.
• Assembly and packaging to ensure exposure of the item(s) to conditions of sterilization
during the process.
• Sterilization as the last step

7. What are the current methods of sterilization?
Most common:

• Steam (preferred for sterilization of critical instruments that are not damaged by heat,
steam, pressure or moisture) by gravity-displacement steam sterilizer or prevacuum
steam sterilizer see below*)

• Ethylene oxide
• Hydrogen peroxide gas plasma
• Peracetic acid-chemical sterilization
• For additional methods, see the discussion contained in the CDC HICPAC Guideline for

Disinfection and Sterilization in Healthcare Facilities, 2008):
o Ozone
o Vaporized hydrogen peroxide
o Steam formaldehyde

Advantages and disadvantages of sterilization methods are reviewed in Table 3.

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Table 3 Sterilization Methods: Advantages and Disadvantages

Sterilization Method Advantages Disadvantages

Steam Nontoxic, inexpensive, easy to monitor, Harmful to heat labile

rapidly microbicidal, least affected by instruments. Burn potential

soils, rapid cycle time, penetrates

packaging and lumens

Ethylene oxide (ETO) – Very effective kill, can sterilize heat Some states require ETO

“gas” sterilization sensitive devices, penetrates packaging emission reduction of 90-99.9%.

and many plastics, compatible with most CFC (inert gas that eliminates

medical materials, easy to monitor cycle. explosion hazard) banned after

1995. Potential hazard to

patients and staff. Lengthy cycle

and aeration time.

Hydrogen peroxide gas No toxic residues, safe for environment No processing of cellulose

plasma and healthcare worker, fast cycle time (paper), linens, and liquids.

(28-52 min.) and no aeration time Small sterilization chamber.

needed. Heat and moisture sensitive Endoscopes/device restrictions

items can be processed under temp 50° based on lumen internal

C. Simple to install, run, and monitor and diameter and length (see

compatible with most devices. manufacturer’s

recommendations). Requires

synthetic packaging

(polypropylene) and special

container tray.

STERIS System 1 Rapid cycle (30-45 min.). Sterilization In December 2009, FDA advised

process by low temperature (50-56°C) users to transition to other

liquid immersion. Environmentally legally marketed technology due

friendly and no adverse health effects to to sterilization failures. The

operators. Fully automated and transition period has now been

compatible with wide variety of extended to February 2012.

materials. Suitable for devices such as

flexible and rigid scopes.

Excellent microbial kill

STERIS System 1E (SS1E) “Steris System 1E should be used only for All liquid chemical processing

-FDA cleared April 2010 processing heat sensitive semi-critical systems have the same

and critical devices that are compatible limitation in that final devices

with the sterilant and processing system emerge wet and unwrapped

and cannot be sterilized by other fully from the processor (not

validated terminal sterilization methods terminally sterilized).

for that device” per Dr. William Rutala, SS1E rinse water is not described

APIC 2011 as sterile. The Steris System 1E

should not be used on critical

devices since, by definition, they

need to be sterile and with SS1E

the final processed devices are

not considered sterile.

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Definitions:
Gravity –displacement steam sterilizer = a sterilizer in which incoming steam displaces air to
the bottom of the chamber and out through a drain near bottom of sterilizer. See
manufacturer’s instructions for parameters for proper operation. This type is not efficient for
complex instruments or lumens.

Prevacuum sterilizer (also known as dynamic air removal) = a sterilizer using one or more
pressure and vacuum methods to rapidly remove air at the beginning of the cycle. See
manufacturer’s instructions for parameters for proper operation. Air is mechanically removed,
making the process more efficient and shorter.

8. Where is “flash” sterilization used?
“Flash” sterilization is an antiquated term for immediate-use steam sterilization (IUSS) for items
not intended to be stored and used later. Immediate use is the shortest possible time between
a sterilized item’s removal from the sterilizer and its aseptic transfer to the sterile field.
Association for Professionals in peri-Operative Nursing (AORN) states that “immediate-use
sterilization [new term replacing “flash”] should be performed only if all of the following
conditions are met:

 The device manufacturer’s written instructions on cycle type, exposure times,
temperature setting, and drying times (if recommended) are available and followed.

 Items are disassembled and thoroughly cleaned with detergent and water to remove
soil, blood, body fats, and other substances.

 Lumens are brushed and flushed under water with a cleaning solution, and rinsed
thoroughly.

 Items are placed in a closed sterilization container or tray, validated for flash
sterilization, in a manner that allows steam to contact all instrument surfaces.

 Measures are taken to prevent contamination during transfer to the sterile field. These
measures consist of sterile gloves and avoiding contact with unsterile surfaces.”

Source: Recommended Practices for Sterilization in the Perioperative Practice Setting,
Perioperative Standards and Recommended Practices. Denver: Association of periOperative
Registered Nurses (AORN), 2010:457-480.

If all of the steps are not met, immediate-use sterilization may increase risk of infections. So
this form of sterilization should be kept to a minimum and only used when insufficient time to
process by the preferred terminal sterilization method. Immediate-use sterilization should not
result from insufficient inventory of instruments. The process should be monitored using a
Class 5 chemical integrator and records kept to be able to track an individual item back to a
specific patient if needed. IUSS should not be used for implants unless a documented
emergency situation exists and should be monitored with a rapid-action Biological Indicator and
a Class 5 Chemical Indicator.

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9. What cycles should be used for steam sterilization?
Various cycles may be used. Some minimal examples are provided for gravity displacement
cycles, pre-vacuum cycles, and abbreviated steam sterilization (immediate-use sterilization).
Users should always check sterilizer manufacturer’s instructions as well as that of the
manufacturer of the device or instrument. Minimal cycle times for gravity displacement steam
sterilization and dynamic air removal steam sterilization are shown in Tables 4 and 5.

Table 4 Minimal Cycle Times for Sterilization: Gravity Displacement Steam Sterilization

Item Exposure Minimum Exposure Minimum Exposure Minimal

time at drying time time at drying time time 275° F drying

250° F 270° F ( 135°C) time

(121° C) (132°C)

Wrapped 30 min. 45 min. 15 min. 45 min. 10 min. 30 min.

instruments

Textile 30 min. 30 min. 25 min. 30 min. 10 min. 30 min.

packs

Wrapped 30 min. 30 min. 15 min. 30 min. 10 min. 30 min.

utensils

Table 5 Minimal Cycle Times for Sterilization: Dynamic Air Removal Steam Sterilization

Item Exposure time at Minimum drying Exposure time at Minimal drying

270 time 275° F (135° C) time

Wrapped 4 min 3O min. 3 min. 16 min.

instruments

Textile packs 4 min. 5 min. 3 min. 3 min.

Wrapped 4 min. 20 min. 3 min. 16 min.

utensils

10. A word about prions:
Prions are misfolded versions of normal cellular proteins that are synthesized in brain tissue
and can cause several neurologically degenerative diseases, one of which is Creutzfeldt-Jakob
disease (CJD). Prion diseases are usually rapidly progressive and always fatal. Prions are highly
resistant to routine sterilization and disinfection methods. Their eradication involves increased
temperature or extended cycle sterilization or combination of both. Refer to the APIC Text of
Infection Control and Epidemiology, 3rd. Ed. (2009), Chapter 93: Creutzfeldt-Jakob Disease and
Other Prion Diseases for comparison of guidelines by Rutala and WHO regarding disinfection
and sterilization of prions.

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11. What types of monitoring of the sterilization process should be conducted?
If it is critical that certain items be sterile, then it is critical that the sterilization process be
monitored in the following ways:

• Mechanical or physical indicator – visible monitor (computer printout or dial) to enable
operator to determine if critical sterilization parameters for each cycle (time,
temperature and pressure) were met during the process. The printout should be
reviewed and signed at the end of each cycle verifying by the operator that all
sterilization parameters were met.

• Chemical indicator – sterilization process monitoring device that is used to monitor one
or more critical parameters required for sterilization. Usually a color change (for
instance, on the tape) indicates the item has been exposed (or processed versus not
processed) to the sterilization process. This does NOT indicate that the item is sterile. A
chemical indictor should be used inside each package to be sterilized and also on the
exterior of the package if not visible from the outside. Chemical indicators (CIs) should
be placed on all levels within the instrument sets. They should be placed in the
geometric center of wrapped packages and in two opposite corners of rigid containers.
There are 6 classes of CIs. The Class 5 indicators are integrating indicators which react to
all three of the critical variables and are appropriate for all steam cycles.

Note: Dynamic air-removal test (Bowie- Dick test) is a diagnostic test performed daily to
determine adequacy of air removal from the chamber of a pre-vacuum steam sterilizer. This
test is not a test of sterilization.

• Biological indicator – sterilization process monitoring device commercially prepared
with a known population of highly resistant spores that tests the effectiveness of the
sterilization method in use. This indicator demonstrates that conditions necessary to
achieve sterilization were met during the cycle being monitored. Steam sterilizers
should be tested at least weekly and preferably daily (class 6 emulating indicators are
not a substitute). Ethylene oxide sterilizer testing should be performed with each load.
Consult manufacturer’s instructions for testing of other sterilizers. All loads containing
an implant should be monitored with a biological indicator (BI) and the implant should
be quarantined until results of the biological indicator are known.

All biologicals should be interpreted by trained personnel in the time period specified by the
manufacturer of the biological test. Results should be documented in the sterilization records.
A control vial should be run with each biological and must be from the same lot number as the
biological test for the test to be considered valid.

Do not use processed items if the mechanical (e.g., time, temperature, pressure) or chemical
(internal and/or external) indicators suggest inadequate processing.

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12. What actions should occur when a positive biological test is identified?
Positive results should be reported immediately so that appropriate actions may be taken. The
sterilizer printout should first be checked to determine if cycle parameters were met. Chemical
indicators should be checked for color change:

a. Single Positive Biologic Indicator with STEAM Sterilization:
Objects, other than implantable objects, do not need to be recalled because of a single positive
spore test unless the sterilizer or the sterilization procedure is defective as determined by
maintenance personnel or inappropriate cycle settings.

If additional spore tests remain positive, consider the items nonsterile and recall and reprocess
the items from the implicated load(s) dating from the sterilization cycle having the last negative
biologic indicator to the next cycle showing satisfactory biologic indicator results.

b. Single Positive Biologic Indicator Used with a Method Other Than Steam Sterilization:
Treat as nonsterile all items that have been processed in that sterilizer, dating from the
sterilization cycle having the last negative biologic indicator to the next cycle showing
satisfactory biologic indicator results. These nonsterile items should be retrieved if possible and
reprocessed.

13. What are acceptable parameters of storage for sterile items?
• Sterile storage area must be a well-ventilated area that provides protection against dust,
moisture, insects, and temperature and humidity extreme
• Store sterile items so the packaging is not compromised (e.g., punctured, bent)
• A label with a load number that indicates the sterilizer used, the cycle or load number,
the date of sterilization, and, if applicable, the expiration date should be on all sterilized
times
• AORN recommends that the shelf life of a packaged sterile item is event related (ie. If
the integrity of the packaging is compromised …e.g., torn, wet, or punctured), then the
item must be repackaged and reprocessed before use; otherwise the item may be used
if no event has occurred to compromise the integrity of the packaging
• Alternatively, some facilities use time storage which means that the label on the sterile
package is applied at sterilization with an expiration date; when the expiration date
expires, the package must be reprocessed

14. What about loaner instruments?
Loaner instruments should be received in sufficient time to allow for processing prior to the
case and should be received in the decontamination area. An inventory sheet and written
recommendations for cleaning, packaging and sterilization should be provided with the loaner
set.

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Resources:
1. Centers for Disease Control and Prevention. Guideline for Disinfection and

Sterilization in Healthcare Facilities, 2008. Available at
http://www.cdc.gov/hicpac/pdf/guidelines/Disinfection_Nov_2008.pdf. Accessed July11,
2011
2. http://www.disinfectionandsterilization.org. Dr. William Rutala’s website.
3. Association of periOperative Registered Nurses. Perioperative Standards and
Recommended Practices. Denver: Association of periOperative Registered Nurses,
2010.
4. Association for Professionals in Infection Control and Epidemiology. APIC TEXT of
Infection Control and Epidemiology, 2009.
5. WHO Infection Control Guidelines for Transmissible Spongiform Encephalopathies:
Report of a WHO Consultation, Geneva, Switzerland, 23-26 March 1999 (as listed on
www.cdc.gov). Available at
http://www.who.int/csr/resources/publications/bse/WHO_CDS_CSR_APH_2000_3/en/.
Accessed on July 11, 2011.

Besides the resources listed above, every operating room, infection prevention, and sterile
processing department professional should have access to The Association for the
Advancement of Medical Instrumentation’s (AAMI’s) Comprehensive guide to steam
sterilization and sterility assurance in health care facilities.

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Checklist for Auditing Sterile Processing Practices

Evaluative criteria Yes No Unable to Comments
Space design Adequate space determine

Floors and surfaces can withstand
frequent cleaning
Doors and windows kept closed

Handwash stations in decontamination
and clean areas are separate from
instrument sinks
Eye wash stations within 10 seconds
travel time
Eye wash stations capable of a 15
minute flush
Work flow is dirty to clean
(decontamination to clean)
All pass-through windows and doors
are kept closed
Authorized personnel only and in
proper attire

Signs adequate for work processes

Cardboard packing boxes removed
from area
Temperature and humidity monitoring
and documented daily
Temperature and humidity maintained
in appropriate ranges (temperature
68-73°F in clean areas and 60-65°F in
decontamination areas; humidity 30-
60% in work areas but not over 70% in
sterile storage)
Ventilation airflow in decontamination
(soiled) area is negative pressure and
provides 10 air exchanges per hour
Ventilation airflow in clean/sterile area
is positive pressure and provides 10 air
exchanges per hour
All areas are cleaned daily using
separate cleaning equipment for
decontamination and clean areas
Ceilings have a flush surface and no
shedding materials.

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Evaluative criteria Yes No Unable to Comments

determine

Staff Orientation and ongoing education

Decontam- documented
ination Area
Competence documented at least

annually

Adheres to dress code of facility-

laundered scrubs donned at facility

Facial hair (except eyebrows and

eyelashes) covered

PPE used and removed properly

Ideally staff should be certified within 2

years of hire.

Contaminated items transported in

covered containers, labeled biohazard

Appropriate PPE available and used

(impervious long-sleeved covering,

heavy-duty gloves, face and eye

protection)

Hands washed after removing PPE

Manufacturer’s written instruction for
equipment, instruments, and cleaning
solutions available and followed
Appropriate cleaning solutions
(containers labeled, expiration date
followed) are available and used
Sharp items are maintained separately

Delicate items are maintained
separately
Saline is never used on instruments

Cleaning is performed at the point of
use as soon as possible
Instruments are kept moist until the
cleaning process has begun
Instruments are cleaned only in
designated sinks in the
decontamination area (not hand wash
sinks)
Instruments are disassembled before
decontamination process begins
Measuring cups and lines are in sinks
for accuracy
Brushing of instruments is done under
water
B rushes are decontaminated daily or
are disposable
Mechanical cleaning equipment should
be used whenever possible

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Evaluative criteria Yes No Unable to Comments

determine

Packaging Instruments free of debris and in good

Sterilization working order
process
Labeling on indicator tape, patient

record cards, and peel packs (plastic

side)

Inventory or count sheets are not

placed inside trays

Instrument sets not over 25 lbs. in

weight; a scale should be available

Double peel pack are not folded;

proper sizing

Peel packs should not be used within

wrapped packages or containerized

sets

Chemical indicator (internal and

external) on all packs (including all rigid

containers) and on all levels

Chemical indicators are placed in the

geometric center of wrapped packages

and in 2 opposite corners of rigid

containers.

No reprocessing of single use devices

Use of instrument tracking system

Peel packs, lighter items on top shelf

Peel packs/linen packs on edge

No pan stacking (unless manufacturer

recommends)

Monitoring of sterilization gauges,

printouts, graphs

Monitoring of chemical indicators

BIs (run at least daily in steam and

peracetic acid; run in every load for

ETO, gas plasma, and vapor phase)

Implants run with BI and class 5

chemical indicator (reacts to all critical

parameters of sterilization versus a

single parameter)--not released until

results of BI are available

Identification of sterilizer documented

with each load

Type of sterilizer and cycle used

documented with each load

Lot control number documented with

each load

Contents of each load documented

All sterilized items are traceable to the

patient

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Evaluative criteria Yes No Unable to Comments

determine

Sterilization Operator’s name documented on each
process
(continued) load

Sterile Results of sterilization process
storage
monitors (physical, chemical,

biological indicators) documented for

each load

Preventative maintenance and cleaning

of each sterilizer performed and

documented

Current manufacturer’s

recommendations are available and

followed

Recall procedure in place and

reportable to Infection Preventionist

Immediate use sterilization items are

properly cleaned

Immediate use items are placed in

closed validated “flash” containers

All parameters documented for

immediate use sterilization items

Aseptic transfer to point of use is

evident for immediate use sterilization

items

Immediate use sterilization is not used

as substitute for insufficient inventory

Sterile items separate from clean

No stacking of heavy wrapped trays

Bottom shelves solid

Cleanable surfaces

Stored items 18” below ceiling (or level
of sprinkler head), 8-10 “ above floor,
2’ from outside walls
Stock rotated (shelf life/event sterility
posted on each package)

No cardboard boxes or outside
shipping containers

Controlled area; properly attired
personnel only

Notes

Tip: Are there policies and procedures on all of the above?
This skill station information compiled by Libby Chinnes, Ruth Carrico and Tricia Just

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