Introduction Sterilization is the complete destruction of microorganisms including bacterial spores. This level of decontamination is required for all reusable invasive medical devices (RMD). Ideally, sterilization methods: • Have rapid throughput • Are easily validated • Are capable of processing wrapped items to enable storage after processing without the risk of environmental contamination of processed items.

1. ALL YOU NEED
TO KNOW ABOUT
CENTRAL
STERILE SUPPLY
DEPARTMENT

2. Sterilization
Sterilization
By Talal Albudayri

3. Introduction
Sterilization is the complete destruction of
microorganisms including bacterial spores. This level
of decontamination is required for all reusable
invasive medical devices (RMD).
Ideally, sterilization methods:
• Have rapid throughput
• Are easily validated
• Are capable of processing wrapped items to
enable storage after processing without the risk of
environmental contamination of processed items.

4. Sterilization is most commonly achieved by using
either thermal energy (heat) or low temperature
chemical processes with the following methods:
• Steam (moist heat) at high pressure—cycle time approximately 40–60 minutes
• Dry Heat, similar to an oven, using normal pressure—cycle time up to 2 hours
• Gas plasma at ambient temperature—cycle time 45–75 minutes
• Ethylene Oxide (EO) at subatmospheric or high pressure
• Low temperature steam and formaldehyde vapor—cycle time

5. moist heat sterilization using steam
under pressure
ADVANTAGE
DISADVANTAGE
it is more reliable and can be
more effectively monitored and
validated.
this method is not suitable for
items that are damaged by
heat or moisture,
WHEN IS STERILIZATION REQUIRED?
THIS IS BASED ON THE SPAULDING
CLASSIFICATION OF RISK ASSESSMENT.
STERILIZATION IS REQUIRED FOR RMD,
MEDICAL DEVICES THAT COME INTO
CONTACT WITH A BREAK IN THE SKIN
OR MUCOUS MEMBRANE OR ENTER A
STERILE BODY CAVITY.

7. Red spot
Choosing the correct sterilization process is important to avoid damage to the item or compromising
sterility.
Sterilization and providing sterile devices for patient procedures is dependent on the whole cycle of :
decontamination, including cleaning, packaging, sterilization, and storage/transport.
Handling the device in theatre may also have an impact on maintaining sterility until actual patient use.

8. Device Compatibility
The ability of the sterilization system to
effectively sterilize the medical device depends
on
the device’s component materials
and design,
as well as the level of bioburden (microbes)
prior to sterilization.
If items are not cleaned and disinfected
correctly, effective sterilization may not be
achieved.

9. Functionality is the ability of a medical device to
withstand the sterilization process and to remain
within operating specifications.
The device manufacturer will test its functionality
after processing through repeated sterilization cycles
and provides fully validated IFU on how to process
the medical devices they supply (ISO EN 17664).

10. Steam Sterilization
The process of steam sterilization
requires direct contact between the
material being sterilized and pure
dry saturated steam at the required
temperature for the required time in
the absence of air.

11. The recommended combinations of time
and temperature
The higher temperature of 134°C for 3 minutes is the preferred time/temperature
for devices that will withstand this temperature and associated pressure.
A steam sterilization cycle involves air being displaced and removed by steam
entering the chamber. This can be done with gravity using a gravity displacement
sterilizer, or with a vacuum using a porous load or vacuum assisted sterilizer.
Air removal is essential for effective sterilization, as it will affect steam access to
all areas of the device or pack.

12. Ethylene Oxide (EO)
These sterilizers operate at 37oC or 55oC suitable for
heat sensitive items
such as invasive flexible endoscopes, and
cardiac and ophthalmic devices.
requires very long cycle durations to allow of
adequate aeration.

13. A typical cycle consists of:
• Load pre-conditioning—vacuum and
humidification
• Sterilizing gas exposure
• Gas exhaust and air purge

14. Ethylene Oxide (EO)
They are used commercially and in some
hospitals.
requirements for operating and
housing these machines.
but are banned in hospital settings in many
countries due to the costly health and safety

15. Ethylene Oxide (EO)
They are used commercially and in some
hospitals.
but are banned in hospital settings in many
countries due to the costly health and safety
requirements for operating and
housing these machines.

16. Ethylene Oxide (EO)

17. Sterilization Validation
(contents) and documentation of the results
• Assuring all components of the process such as proper
Validation establishes documented evidence providing a high
cleaning, functionality, packing, wrapping are met
• Proper protocol management
degree of assurance that a specific process will consistently
produce an end result meeting specifications and quality
attributes by:
• Measuring the critical parameters of the process such as
temperatures, time and pressure, load configuration

18. Steam Sterilizer Testing
Routine testing of sterilizers should be
performed daily, weekly, quarterly
and yearly as per ISO 17665.

19. Daily
Bowie-Dick test
air removal test).
for steam penetration (also known as

20. Weekly
• Safety checks
• Vacuum leak test
• Air detector function test (if
equipped)
• Automatic control test
• Bowie-Dick test
Quarterly
• All the above plus
• Thermometric test,
• Surgical instrument calibration
verification

21. Yearly
-Non-condensable
gas --Steam drynes
-s –Endotoxins
• Thermocouple test
• All the above plus
• Steam quality tests
--Steam superheat
• Testing of dry heat sterilizers
• Biological indicators
• Chemical indicator

22. Ethylene Oxide Sterilizer Testing
• Physical parameters i.e.
temperature, pressure and humidity
• Biological indicators
• Chemical indicator
Gas Plasma Sterilizer Testing
• Physical parameters i.e.
temperature, pressure
• Biological indicators
and humidity
• Chemical indicators

23. Gravity Displacement Steam
Sterilizers
This type of sterilizer has no assisted air
removal and is dependent on gravity.
The disadvantages of this method:
1- so steam penetration is slow and cannot be assured.
2- Cycle times are much longer for this type of sterilizer and
load selection is critical.
3- They are not suitable for wrapped items or items with
channels (lumens) as they trap air and prevent correct
temperatures from being attained.
Gravity displacement steam sterilizers may be used for: solid
metal items such as non-complex surgical instruments.

24. Porous Load (Vacuum Assisted) Steam
Sterilizers
Porous load sterilizers incorporate a
vacuum-assisted air removal stage prior
to steam admission and they require a
consistent supply of suitable quality
steam.

25. A typical cycle consists of:
• Evacuation of air from the chamber and load, assisted
by flushing or pulsing with steam
• Sterilization of the load for not less than 3 mints at 134o
C
• Steam removal and load drying by mechanical
evacuation
• Admission of filtered air to restore atmospheric pressure

28. Steam Quality
Proper steam quality will prolong the life of RMDs by
reducing water impurities that have adverse effects
on device materials.
Lime, rust, chlorine and salt can all be left as deposits
on devices if treated (reverse osmosis) water is not
used.
These compounds can lead to stress corrosion, pitting
and discoloration of the devices and the sterilizer.

29. Pitting, corrosion and precipitates provide areas where
organisms can accumulate and be protected from the
killing effects of the steam process; increasing the infection
transmission risk due to inadequate sterilization.

30. Loading
Load steam sterilizers in the following manner to ensure
steam contact and penetration:
• Avoid overloading
• Place non-perforated trays and containers on their edge
• Keep packages away from chamber walls
• Place concave devices on an angle to avoid condensate
pooling
• Load textile packs perpendicular to the sterilizer cart shelf
• Place pouches on their edge
• Place multiple packages paper to plastic
• Do not stack rigid containers unless validated by the
manufacturer

31. Unloading
When the cycle is complete, unload the sterilizer in the following
manner
: • Place heavier items, trays and containers on lower shelves and
lighter items e.g. peel packs on higher shelves
• Review the sterilizer printout for the following:
• Correct sterilization parameters
• Cycle time and date
• Verify that the cycle number matches the lot control label for the
load
• Verify and initial that the correct cycle parameters have been met
• Examine the load items for:
• Any visible signs of moisture
• Any signs of compromised packaging integrity
• Retain printed records of each cycle parameter (i.e., temperature,
time) in accordance with the local policy e signs of moisture

32. Load Cool-Down
After removing the sterilized load:
• Visually verify the results of the external
chemical indicators
• Allow the load to cool to room temperature
before touching or moving sterile packs. The
amount of time for cooling depends on the
devices that have been sterilized for example, a
heavy item such as an orthopedic mallet may
require a longer cooling time
• Ensure that cool-down occurs in a traffic-free
area without strong warm or cool air currents

33. Troubleshooting—Wet Pack Problems
Packages are considered wet when moisture in
the form of dampness, droplets or puddles are
found on or within a package.
There are two types of wet packs; those with
external wetness and those with internal wetness.
When wet packs are found, either on removal from
the sterilizer or upon opening in the operating
theatre, sterility is considered to be compromised
and the package contents may be contaminated.
Wet packs should be rejected and re-processed
according to the local policy.

34. Steam Sterilization: Advantages and
Disadvantages

36. IUSS System (flash sterilization)
operate at
Immediate use steam sterilization (IUSS)
environment.
134oC for 3–10 minutes
use steam sterilization (IUSS) or flash sterilization is a
common term that describes the practice of fast
sterilization of surgical instruments at the point of use
often associated with dropped instruments
in order to process instruments for extremely
urgent use
resulting in wet and very hot medical devices in the operating room

37. Flash sterilization is
of:
•
non-porous and/or non-hollow surgical
instruments in an unwrapped condition.
usually located in
the operating room
a dropped instrument when no
alternative is available.
example

38. Indications for Use of IUSS
An IUSS sterilizer must be used only after all of the
following
conditions have been met:
• Proper cleaning, inspection, and arrangement of
surgical
instruments before sterilization
• Physical layout of the area which ensures direct
delivery of
sterilized items to the point of use
• Procedures are developed, followed and
audited to ensure
aseptic handling and staff safety during transfer
of the
• Items are needed for use immediately following
IUSS, as
• Sterilizers are routinely tested prior to use and
appropriate
sterilized items from the sterilizer to the
point of use soon as the device cools so as
not to burn the patient records maintained

39. There is now a strong movement towards
the routine preparation of sterile
instruments in a dedicated area
like the CSSD for the following
reasons:
• Immediate advantages of case-by-case organization of sterile
instruments by operating theatre staff.
• The typical operating theatre is not designed or equipped to
wash and clean instruments as reliably and consistently as a
properly located and designed CSSD, and there are concerns
regarding the adequacy of cleaning and drying of surgical
instruments in the operating theatre prior to using IUSS
processing.
• Sterility of sets of instruments can be uncertain following the use
of sterilisers designed and intended only for single
dropped instruments; they should not be used for routine
sterilization of instrument sets.
• The sterilizer may not be located in an area immediately
adjacent to the operating theatre; so the delivery of IUSS-
sterilized devices to their point of use compromises their sterility

40. IUSS Recommendations
• Restrict use to emergencies, such as
unexpected
surgery, or dropped devices
• In most emergency situations, the
risk/benefit
ratio is low enough to justify the use of
IUSS-
sterilized devices
• IUSS sterilizers must never be used for
implants, suction tubing or cannulaeor
any other product
not specifically validated for the IUSS
process.
In non-emergency situations, the risk/benefit ratio is higher,
particularly when implantable devices are involved

41. Dry Heat Sterilization
The dry heat method may be used for glassware
and metal items, heat stable powders and non-
aqueous liquids like paraffin.
his process does not use steam so the typical times
required for sterilization are much longer.
A typical cycle consists of heating the chamber to
the required sterilization temperature, holding
the load at this temperature for a defined
time period and then cooling the load.

42. The typical time and
temperatures used are:

44. Low Temperature Sterilization
Considerations
• Temperature involved—is the method
compatible with the devices being
processed?
• Cycle time—will this fit with the
workload/turnaround time of the CSSD? Will
more devices be required?
• Availability of equipment
• Validation requirements
• Compatibility with devices being processed

45. Gas Plasma
This method is also suitable for heat
sensitive items
such as flexible endoscopes or complex
laparoscopic instruments as the
operating
temperature is 45oC.
The cycle time can vary from 45–75
minutes but no
aeration is required.
A typical cycle consists of a vacuum
to remove air,
injection and diffusion of the hydrogen
peroxide
and generation of the plasma for a
defined
sterilization time, followed by aeration and
venting.

47. Thank
Thank
you!
you!
By Talal Albudayri