Basics of Sterilization
David R. Woodard, MSc, CIC
Dr. Earle Spaulding
“You
can clean without
disinfecting, but you cannot
disinfect without cleaning”
Decontamination Area


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The location designated for the collection,
retention, & cleaning of soiled instruments
Physically separated from all other areas
to decrease risk of cross infection
Air from decontam area is exhausted to
the outside and not recirculated
Types of Cleaning

Decontamination


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Process that removes as many
microorganisms as possible by physical,
mechanical or chemical means
Also known as cleaning
Utilizes water, detergent and enzyme soln

Enzyme separates blood, bone and tissue from
instruments
Types of Cleaning

Disinfection


Immediate state between physical cleaning &
sterilization
Uses thermal processes or chemical
germicides
Manual Cleaning of Instruments

Cleaned under water with nonabrasive
neutral PH detergent

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Low sudsing and & does not leave residue
Special attention given to hard to clean
areas
Items with lumens are cleaned with
brushes and flushed with water
Inspection of Instruments

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Cleanliness, & absence of corrosive substances
Free motion of hinged instruments-absence of
stiffness
Proper alignment of jaws & teeth
Proper tension with closed ratchets
Sharpness of blades, trocars, absence of burrs,
gouges
Screws and pins are clean
Inspection Con’t
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General integrity-absence of cracks, dents,
chipping, worn areas
Intact insulation sheathing, absence of tears
Items composed of more than one part are
complete & parts fit together securely
Powered surgical instruments appropriately
lubricated & tested for proper functioning
Preparation of Instruments

Remove gross soil at point of use

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Jaws, blades, serrations, box locks commonly retain
high levels of bioburden
Remove blood/tissue with water & sponge

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↓number of organisms
Reduces nutrient material that promotes bacterial growth
Minimizes potential for environmental contamination
Removes substances that damage the instruments
Organization of Instruments

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Maximize surface area of instruments
Place instruments in a mesh bottom tray to
allow for full exposure of cleaning mechanism
Open jointed instruments at box locks
Disassemble instruments composed of more
than one part
Separate delicate scissors & microsurgical
instruments from heavier instruments to avoid
damage
Assembly of Items for Sterilization

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All hinged instruments must be opened &
secured with stringers in a wire mesh basket
The weight of an instrument set should be
evenly distributed to avoid collection of moisture
during sterilization
A towel may be positioned in the tray to
facilitate revaporization of condensate
Delicate instruments require tip guards/foam
Count sheet in every tray
Packaging Materials

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Items must be packages in a manner that
maintains their sterility
Appropriate packaging material

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Allows effective sterilant penetration
Must contain the sterility of the processed
items
Must allow aseptic presentation of contents
Paper-Plastic Package System

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Allows for proper sealing to secure contents
Remove as much air as possible to facilitate
effective sterilization
Double peel packages should be sequentially
sized & sealed to allow fro proper fit of inner
pouch
Paper sides of both packages are positioned
together to allow adequate penetration of the
sterilant
Rigid Sterilization Containers


Reduce cost and management of waste
Perforations in the lid and bottom are
covered with disposable bacterial filters

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Filters allow sterilant to penetrate
Tamperproof locks & ID labels
Need to follow recommended weight,
density, sterilization cycles & times &
loading practices
Storage of Packaging Materials


Room temperature
Humidity 35% to 70%

High humidity

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Packaging may become over hydrated which can
affect integrity of adhesives & seals of peel
packages
Low humidity
Dehydration
 Brittle and easily tear

High Level Disinfection


Uncontrolled process
Efficacy is directly affected by the
cleanliness of the device, preparation of
the device, the level of the active
ingredient, temperature of solution and
the exposure time

Testing the solution according to directions
Chemical Disinfection
(Cidex OPA)
High Level Disinfection



Performed by submersing an item in a
covered basin of germicidal solution for a
designated length of time to achieve the
desired level of microbial kill
May eliminate many or all pathogenic
microorganisms
Will not kill spores
Disinfecting Issues

Product must be:

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Tested once each day of use or each time
used when not used daily.
Changed as manufacturer requires
Test strips tested for accuracy (high/low) at
time of introduction to use
Test strips expire!
Temperature sensitive
Disinfection

Improper cleaning and organic debris are
among many factors that have been
known to nullify or limit the efficacy of this
process.
Washer Sterilizers

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Wash, rinse, & use gravity steam sterilization
High temps & steam leads to total destruction
but they should not be considered ready or safe
for patient use
Must clean & remove bioburden

Tissue or debris not removed during wash cycle may
be baked on during sterilization cycle
Advantages of Washer Sterilizer

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↑ penetration capability
Exposure of higher temps to all surface areas
Greatest incidence of microbial lethality
Automatic time-released lubrication cycle
Sterilization

The process of killing all forms of microbial
life
 Class I – External, time, temp, pressure indicator, says
item went through autoclave (tape, peel packs)
 Class II – Bowie Dick, checks for air removal
 Class III – Internal, time & temp, rarely used today
 Class IV – Internal, reacts to two or more parameters,
rarely used today
 Class V – Integrators, melted chemical pellet, reacts to
all parameters, all steam cycles
 Class VI – Emulating indicators, cycle specific
 Biological – gold standard, shows kill of organisms
WELCOME
TO
DECONTAM
AUTO WASHER
WORK TABLE
WELCOME
TO
STERILE PROCESSING
READY
FOR
STERILIZATION
WORK AREA
OBSOLETE
EQUIP / INST
COUNT SHEETS
Steam Sterilization
Moist Heat

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Most economical & efficient
Rapid processing time allows frequent
availability
Items must be able to tolerate high temps
& moisture
Works with time, temperature & moisture
Steam Sterilization
Time, Temperature, Moisture

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Steam circulates within the jacket space surrounding
chamber
Steam enters the chamber & displaces all the air

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Air and steam do not mix
As pressure increases, saturated steam contacts all
surfaces , penetrates packages, & forces air out through
a drain at the bottom of sterilizer
Sterilization is initiated once all air is removed
High temp of saturated steam causes microbial
destruction
Proper loading is crucial to allow the steam to freely
circulate
Steam Sterilization Con’t
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Temperature affects the time of exposure
in that the higher the temperature, the
less exposure time is required.

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As pressure ↑ in a closed chamber, so does the
temperature
If these parameters are not represented in
a cycle, sterilization will not occur
Cycle Phases

Conditioning
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Exposure
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Load is heated to sterilization temp
Exhaust
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Air removal
Bottom drain opens and steam is exhaused
Drying

Dry heat revaporizes existing moisture & removes
from the load
Proper Loading & Unloading

Proper Loading

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Prevents formation of air pockets & obstructions to
the circulation of steam
Proper Unloading

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Hot packages are allowed to cool before being
handled
Moisture will form upon contact and cause
contamination

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Called strike through
Do not place hot items on cool surfaces
Sterilization Process Monitors
Chemical Monitors
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(Indicators)
Monitor one or more process parameters of a
sterilization cycle
Detects failures in packaging, loading or sterilizer
function
Consist of a sensitive chemical or ink dye that develops a
visual change after the exposure to certain physical
process conditions (temp & humidity)
Placed on the outside of every package
Need to be examined after sterilization & before use
Chemical Monitors Con’t
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Internal monitors placed in the area of greatest
challenge within the package
Visible once package is opened
Both internal l& external indicators reflect
exposure of an item to one or more sterilization
parameters
Do not guarantee sterility
If questionable, item is not considered sterile
Biologic Monitors

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Standardized preparation of known
microorganisms highly resistant to a
specific mode of sterilization.
Their purpose is to reveal evidence of the
efficacy of a sterilization cycle by utilizing
a high number or resistant spores to
challenge the function of the sterilizer.
Most reliable monitors
Biologic Monitors Con’t
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After cycle is complete put in incubator to
observe microbial growth
Negative biologic monitors contain no growth &
indicates that conditions necessary for
sterilization & microbial kill were met
If growth detected:

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Notify supervisor immediately
Further test & evaluate to determine viability of
organisms & efficacy of the cycle
Biologic Monitors Con’t
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Bacillus stearothermophilus
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Bacillus subtilis

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Steam sterilization
Gas sterilization
Impregnated on paper strips or capsules
and placed within the chamber

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Special test packs or
Wrapped in items
Biologic Monitors Con’t
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A control biologic monitor, which has the
same lot number, as the test and has not
bee exposed to a cycle is also incubated
and examined for growth
Routine Biologic Monitoring

Frequency of Use:

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During installation of sterilizer or after major
repairs
Daily in steam autoclaves
Gas-with each load
Any load with implants
Routine Biologic Monitoring
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Placement:
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Steam
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Gas
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In loaded chamber over drain or coolest part of sterilizer
In the middle of the loaded chamber
Incubation:
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Usually 48 hours
1 hr incubation monitors available for gravity displacement
steam sterilizers
Bowie Dick Test
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Daily air removal test
Insures proper function of the vaccuum
and detects any air leaks
Monitor is placed on the bottom rack over
the drain before the first load
Satisfactory test occurs when there is a
uniform color change
 Following the autoclave
cycle, the BI is placed in
an incubator; also a
control
 Length varies with the
product; rapid readout 1-3
hours, or 24 hours
 Positive test = sterilization
process has failed due to
improperly processed load,
failure to meet
temperature or exposure
parameters, mechanical
Yellow = pus
FAIL
Purple = bugs
killed, PASS
Ethylene Oxide Sterilization
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Used to sterilize heat-labile and/or
moisture-sensitive items
Toxic & flammable
Lengthly processing /aeration time
High cost
Environmental concerns
ETO Sterilization
Gas

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Colorless, noncorrosive, highly penetrative
For items that are sensitive to high
concentrations of moisture and/or heat
Appropriate conditions of time, (105-300
min) temp, (low) EO concentration,
relative humidity (45%-74%)
Appropriate aeration is required to remove
residual EO
EO Aeration

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Continuous currents warm filtered air
12 hrs = 120 degrees
8 hrs = 140 degrees
Hydrogen Peroxide Gas Plasma
Sterilization
Sterrad

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Rapidly destroys microorganisms utilizing low
temperatures without toxic residue
Used for heat and moisture sensitive items
Uses radio frequency energy to vaporize
hydrogen peroxide
Takes approximately one hour
For narrow lumens that are longer than 12” or
narrower than ¼ “ , a special adaptor is needed
Chemical Sterilization
The Steris

Used on items that are heat sensitive

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Delicate instruments, scopes, cameras
Uses a lower temperature & shorter cycles
Peracetic Acid
Steris
Peracetic Acid Sterilization
“Just In Time”
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Peracetic Acid
Acetic acid, hydrogen peroxide, water
Adversely reacts with protein & enzymes of
microorganisms penetrating cell wall & causing
destruction
Sterilant mixes with water, which reduces
concentration of the acid
Takes about 30 minutes
Works by time, temp and concentration
Immediate Use Sterilization

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Only used in special situations
Use open , perforated mesh bottom trays
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Trays with lids may impede air removal &
steam penetration
Gravity displacement method
Disassemble all instruments
Flush lumens with distilled water
Flash Sterilization Con’t
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Parameters
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Simple instruments
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Gravity displacement 270 degrees for 3 minutes
Complex instruments

Gravity displacement 270 degrees for 10 minutes
Flash Sterilization Con’t
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Several like instruments can be sterilized
together
More than 1 instrument tray requires 10
min
Lumens must be flushed with water
Trays with rubber or cloth run for 10 min
Flash Log
The same tracking process as for items
put up in CS.
Review daily for compliance
Report to ICC and department of surgery
at regular intervals
Use to support additional sets
“We need to flash the hyster tray
because we only have one”
Issues

Documentation

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Pt name/MR #
Items in load
User initials
Recalls

Policies and Procedures
Sterility

The loss of sterility is related to an event,
not to time.

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Germs don’t have a calendar that says – “ok it
28 days, lets contaminate the Kockers”
Events –
Dampness
 Loss of package integrity
 Dirt

Why Expiration Dates?

Why are their expiration dates if we
believe that sterility is event related?

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Commercially prepared products are tested
for sterility at time intervals (the guarantee).
At some point in time, they stop testing, and
that’s as long as the guarantee can be made.
Scopes the bane of our
existence
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Which scope was used on which patient
Cross contamination

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Biological
Tissue
Disinfection
Storage
Problems in Ambulatory
Infection Control
 Many well-publicized outbreaks in
ambulatory centers
 Two main causes:
Unsafe injection practices
Improper cleaning, disinfection,
sterilization of instruments, endoscopes
 Nevada & Nebraska outbreaks resulted in
criminal charges and license revocations
CMS IC Requirements
 Must list national guidelines being used
 Follow them!

CDC/HICPAC Guidelines:

Guideline for Isolation Precautions (CDC/HICPAC)

Hand hygiene (CDC/HICPAC)

Disinfection and Sterilization in Healthcare Facilities (CDC/HICPAC)

Environmental Infection Control in Healthcare Facilities
(CDC/HICPAC)

Perioperative Standards and Recommended Practices (AORN)

Guidelines issued by a specialty surgical society / organization (List)
Please specify (please print and limit to the space provided):
CMS IC Requirements
 NOTE!
If the ASC cannot document that it has
designated a qualified professional with
training (not necessarily certification) in
infection control to direct its infection control
program, a deficiency related to 42 CFR
416.51(b)(1) must be cited.
 Lack of a designated professional responsible
for infection control should be considered for
citation of a condition-level deficiency related
to 42 CFR 416.51.
CMS IC Requirements

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Prefilled syringes- single patient use
IV bags- single patient use, spike just
prior to use
IV tubing and connectors- single
patient use
Sharps safety devices, proper disposal
The Great Clave Experiment…
15 clave ports from 15 different
hospital units were randomly selected
and cultured. 11 of the 15 grew CoagNeg Staph or Staph Epidermidis plus
lots of other nasty stuff. Four cultures
grew nothing…
(but 2 of them were from brand new IV sets…)
Scope Processing
 Written
policy and procedure for:
 Immediate post-procedure cleaning,
leak testing, what to do if it fails
 Thorough cleaning, brushing channels
 Proper connections for AERs
 High-level disinfection/sterilization
 Manufacturers’ written instructions