sterilization healthcare

STERILIZATIONHEALTHCARE

Steam Sterilizers Operation and Preventative

Maintenance

Sterilization: A process by which all forms of microbial life including bacteria, viruses, spores, and fungi are destroyed

Note: In a sterilization process, the nature of microbial death is described by an exponential function. Therefore, the presence of microorganisms on any individual item can be expressed in terms of probability. While this probability can be reduced to a very low number, it can never be reduced to zero. (ANSI/AAMI ST46)

Sterilization Fundamentals

Sterility Testing: Product is inoculated directly into growth medium.

Process Monitoring: Use of mechanical, biological and chemical indicators to monitor critical sterilization parameters.

Parametric release: Declaring product sterile based on records demonstrating that the process parameters were delivered within specified tolerances. This method does not include the use of Biological Indicators.

General Terminology Review

General Terminology Review

• Bio Burden– # of microorganisms on a contaminated item

• Reduction of Bio Burden:– Hand washing; soap and water

– Chemical; high level disinfection

– Sanitization

– Decontamination

– Disinfection

What is a Steam Sterilizer ?

Steam sterilizers for healthcare have one primary purpose:

Technology Fundamentals

Render instruments sterile for re-use in a

surgical setting

Steam Sterilizers– Temperatures ranging from 121-134C at pressures of 15-30

psi are generally recommended to sterilize wrapped or unwrapped surgical instruments.

– Why Steam?


HighlyEffectiveNon

Toxic

Readily Available

Easy to Control

Inexpensive

Two Types of Steam Sterilizers:

Vacuum: used for large volumes of wrapped surgical instruments

Gravity: used for individual unwrapped surgical instruments



Alternate Sterilization Technologies:ETO (Ethylene oxide)

Gas PlasmaOzone

Dry Heat Sterilizers

Low temp.

Ultra High temp.

• Healthcare Steam Sterilizers– Typical Dimensions:

• 16“ wide x 16" high x 16" long (gravity or vacuum)

• 20“ wide x 20" high x 38" long (gravity or vacuum)

• 24“ wide x 36" high x 36" long (usually vacuum)• 24“ wide x 36" high x 48" long (usually vacuum)• 24“ wide x 36" high x 60" long (usually vacuum)• Floor loader: 26.5 x 62 x up to 76”


small

medium

large

• Steam Sterilizers– Smaller sterilizers: instruments

inserted individually for quick sterilization

– Larger sterilizers (36" or larger): can hold entire “carriage” of instruments for sterilizing

– Floor loader: rises to floor level where entire cart and carriage of instruments are inserted for sterilization


Factors Affecting Sterilization

• Time

– Sterility Assurance Level (SAL) 10-6

– One survivor out of a million (infectious organisms)

• Temperature

– 250F/270F/275F

• Moisture

– Required to coagulate protein

– However, steam quality requires a maximum vapor content of 3%


Steam Quality Through RO Water

• Reverse-Osmosis (RO): the process of squeezing water through a semi-permeable membrane.

• RO will separate pure water molecules from dissolved solids such as Calcium, Sodium and Iron

• Chlorine, Nitrates and Nitrites are removed in the pre-filtration process.


Benefits of RO in Steam Generation ( Clean Steam)

Balances pH

Reduces downtime

Reduces costly repairs

Extends useful equipment life

Removes hardness

Improves equipment reliability


Proper sterilizer design and use to achieve time and temperature

Sterilizer area design and quality utilities feeding unit

Bio Burden reduced prior to sterilization

Adequate contact of the sterilant for all surfaces

Other Factors Affecting Sterilization


Air and steam do not mix

Air inhibits steam contact

Air is 1.6 times denser than steam

Steam condenses on cool goods

Loading and load size

Packs must be dry

Why is air removal important?


• Decimal Reduction Value (D-Value)• The exposure to sterilant

required to reduce the population of test organism by 90% (one logarithm) under stated conditions.

• Sterility Assurance Level (SAL) • Probability of a non-sterile unit.

As a minimum sterilization cycles are designed to provide a 1 in a million chance of a non-sterile unit. SAL = 10-6

0.0000010.000010.00010.0010.010.1

110

1001000

10000100000

1000000

exposure10-6

SAL

S K

No

D-value

SAL


More about D-Value and SAL...

The SAL is extrapolated from the survivor curve based on the D-value of the Biological Indicator and exposure time.

Traditional cycle development is driven by determining the time for complete kill of a 106 BI and double the cycle time to achieve SAL of 10-6


3 Primary Factors of Sterility Assurance

1. Process Control - Reproducible and controlled conditions

2. Process Monitoring - Biological indicators, chemical indicators, mechanical gauges, cycle charts or printouts, etc.

3. Good Manufacturing Practices (GMP) - Includes record keeping, inspection of materials, process validation and equipment maintenance and calibration


Complete sterility assurance can only be achieved by testing each item processed - a destructive and impractical

procedure.

Sterilization Cycle Talk: Getinge Vacuum Cycle


The actual sterilizer cycle as logged in our digital software solution, T-Doc

Sterilizer Maintenance

• Why should we have preventative maintenance on a sterilizer?

• What happens in the sterilizer during a cycle?

• What should I look for the start of my shift?

• What can effect the sterilization process that I can control?

• What can effect the sterilization process that I can not control directly?


Why should we have preventative maintenance on a sterilizer?

1. Keeps the machine running to manufactures recommended specifications

2. Minimizes the amount of downtime

3. Provides assurance that the unit is running optimally

4. Extends the life of the sterilizer

5. Ensures the unit is safe for operating- no chamber cracks, faulty valves etc

6. Ensures the appropriate sterility is met by the system as it was intended to provide at time of manufacturing


Sterilizer Video - What Happens during a sterilization cycle


What should I look for when start of my shift?

1. Ask the person who you are replacing if there have been any autoclave problems during their shift. Keep a log book of events for of date, time, unit number, copy of print out and what occurred.

2. Check gasket for wear and tear on the machines you are using

3. Check chamber and drains to ensure no paper or items are obstructing the drain

4. Check the printer paper to ensure you have enough

5. Verify you have appropriate materials for logging, biological tests and bowie dick tests if required for your shift

6. Check to see if you’ll be required to process stat loads etc during your work period to allow you to manage the flow


What can effect the sterilization process that I can control?1. The proper loading and spacing of the sterilizer cart/trolley

2. Using the proper packaging material

3. Checking to ensure drain is not plugged and is cleaned at regular intervals

4. Cleaning of the chamber and carts at regular intervals

5. Proper cool down area away from air conditioning

6. Items being sterilized are dry, containers, blue silicone liners dry as well as plastic bowls etc

7. Being able to properly read the tests – BD, Biological, Indicators, Integrators etc

8. Prequalification of the units after a major repair of the sterilizer


What can effect the sterilization process that I can not control directly?

1. The sterilizer malfunctioning

2. Steam supply staturation drops below 97%

3. Water pressure drops

4. Electrical power failure

5. Failure of BD Test – redo test and check results – 2nd failure contact service for repair

6. Consistently wet steam or dirty steam – (tea effect) – You can perform a warm-up prior to the bowie dick test and this will help remove as much moister from the lines as possible.

7. Dirty steam – you can have filters placed at the feed of the units to filter out debris and some of the chemicals used by maintenance to clean the steam lines

Who establishes the proper sterilization parameters for reusable medical devices?

Who establishes the proper sterilization parameters for reusable medical devices?

Answer: The responsibility for safe and effective sterilization of reusable medical devices is the shared responsibility of both manufacturers, and users of the devices. Reichert & Young, p. 132


Summary - Key Learnings

• Reviewed General Terminology

• Reviewed the Sterilization Fundamentals

• Reviewed Sterilizer Maintenance and areas that can be controlled by MDRD employee


Questions?

Thank you for your Time

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