Bio Safety & MonitoringCentral Sterile Supply Department

CSSDDr.T.V.Rao MD

Dr.T.V.Rao MD 1

Biosafety and Monitoring the CSSD is Priority and responsibility of everyone

in Health care • The central sterile supply

department (CSSD) plays a key role in providing the items required to deliver quality patient care. To support infection control within the healthcare facility, the CSSD staff members must be well-trained and skilled, and committed to “doing what’s right” The shortcuts are never made and that processes and practices are consistently followed.

• Dr.T.V.Rao MD

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What is Central sterile supply department

• Central sterile supply department( CSSD) is a service unit in a hospital that processes, issues, and controls the sterile stores supply to all departments of the hospital. It can be defined as that service, with in the hospital, catering for the sterile supplies to all departments , both to specialized units as well as general wards and OPDs

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We Need constant Monitoring of the Biosafety

of the Instruments and materials used in Hospitals

• The most common method for sterilization of medical instruments worldwide is steam sterilization. However, steam sterilization or autoclaving may not be 100% effective at killing all microorganisms under all circumstances. Therefore, the quality of sterilized products should be assessed by physical, chemical, and biological indicators.

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What CDC Recommends

• According to CDC and other medical associations, to ensure heat penetration to all instruments during each cycle, a chemical indicator should be placed inside and in the center of a load of unwrapped instruments, routinely in every sterilization process. Finally, biological indicators are used periodically for monitoring of the quality of sterilization processes

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Monitoring CSSD• The sterilization

procedure should be monitored routinely by using a combination of mechanical, chemical, and biological indicators to evaluate the sterilizing conditions and indirectly the microbiologic status of the processed items.

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Care of Mechanical Monitors

• The mechanical monitors for steam sterilization include the daily assessment of cycle time and temperature by examining the temperature record chart (or computer printout) and an assessment of pressure via the pressure gauge.

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Monitoring Ethylene Oxide

Monitors • The mechanical monitors for

EO include time, temperature, and pressure recorders that provide data via computer printouts, gauges, and/or displays. Generally, two essential elements for EO sterilization (i.e., the gas concentration and humidity) cannot be monitored in healthcare EO sterilizers.

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Why Chemical Indicators are Preferred

• Chemical indicators are convenient, inexpensive which indicate that the item has been exposed to the sterilization process. But, Chemical indicators were more likely than biological indicators to inaccurately indicate sterilization even during very short sterilization times (e.g., 2 minutes).

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Criteria of Classification • These classifications

are based on Spaulding’s classification of criticality of materials with regard to infection control and cost considerations

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Earle Spaulding Defines the Criteria of classification

• A young doctor from Philadelphia, Earle Spaulding, took on the task of testing germicides, antiseptics, soaps, and cleansers against specific germs. In a paper he published in 1939, he proposed a classification system that is still used today: The Spaulding Classification Scheme. He proposed that classifying medical devices based on the degree of risk for infection would lead to a better understanding of the degree of cleanliness required, and as a result, improve compliance and reduce infection. His simple and logical

categories are "Critical," "Semi critical," and "Noncritical."

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Still We Need Biological Indicators

• Chemical indicators should therefore only be used in conjunction with biological indicators. It should not replace them, because they give incorrect indication of sterilization even at marginal sterilization time.

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Biological monitoring system

• The biological monitoring system depends on live nonpathogenic bacterial spores and stringent sterilization requirements.• The biological indicators are

prepared using a live bacterial spore strip containing a minimum of 1 million live spores.

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Criteria for Selection of Biological Indicators

• All of the biological indicators are approved by theAmericanType Culture Collection and are also tested using the biological indicator evaluator resistometer. The D-value of biological indicator is defined as “the time required in minutes at a certain temperature (121°C) to reduce the number of viable microorganisms by a factor of 10,”5 and the Z-value of a biological indicator is defined as “the number of degrees in Centigrade to reduce the D-value with a factor of 10,

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What is Sterilization

Assurance Level The sterilization assurance level is the “probability of a single unit being non-sterile after it has been subjected to sterilization.” Finally, the entire set of biological indicators after sterilization is sent to the

microbiology department for sterility assurance testing.

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Why Still we Need Biological Indicators

•Only a biological indicator consisting of resistant spores can measure the microbial killing power of the sterilization process. Chemical indicators are affixed on the outside of each pack to show that the package has been processed through a sterilization cycle, but these indicators do not prove sterilization has been achieved. Preferably, a chemical indicator also should be placed on the inside of each pack to verify sterility penetration.

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What are Chemical Indicators

• Chemical indicators usually are either heat-or chemical-sensitive inks that change color when one or more sterilization parameters (e.g., steam-time, temperature, and/or saturated steam; EO - time, temperature, relative humidity and/or EO concentration) are present.

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Chemical Indicator Classes Defined:

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Classification of Chemical Indicators

• Chemical indicators have been grouped into five classes based on their ability to monitor one or multiple sterilization parameters

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Class 1 : Process Indicators

• “Process indicators are intended for use with individual units, (e.g., packs, containers) to indicate that the unit has been directly exposed to the sterilization process and to distinguish between processed and unprocessed units. They shall be designed to react to one or more of the critical process variables.”

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Process Indicators

Applications• Applications : Indicator

tapes, indicator labels, and load cards are examples of externally visible Chemical Indicators that are Process Indicators used for exposure control.

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Class 2 : Indicators for use in Specific Tests

• “Class 2 indicators are intended for use in specific test procedures as defined in relevant sterilizer/sterilization standards.”

• Applications : Bowie-Dick type tests are specific tests used for equipment controlto evaluate the sterilizer performance.

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Class 3 : Single Variable Indicators

• “A single variable indicator shall be designed to react to one of the critical variables and is intended to indicate exposure to a sterilization process at a stated value (SV) of the chosen variable.”

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Applications• An example of a Single Variable

Indicator is a temperature tube that contains a chemical pellet that melts at a specific temperature. Single variable indicators may be used for pack control monitoring but would not provide as much information as a Class 4 or Class 5 Chemical Indicator.

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Class 4 : Multi-variable Indicators

• “A multi-variable indicator shall be designed to react to two or more of the critical variables and is intended to indicate exposure to a sterilization cycle at SVs of the chosen variable.”

• Applications : Multi-variable Chemical Indicators are used for pack control. These internal Chemical Indicators are usually paper strips printed with a Chemical Indicator.

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Class 5 : Integrating Indicators :

• “Integrating indicators shall be designed to react to all critical variables. The SVs are generated to be equivalent to, or exceed the performance requirements given in the ISO 11138 series for BIs.”

• Applications : Integrating Indicators are the most accurate of the internal Chemical Indicators. Integrating Indicators are used for pack control monitoring. They can also be used as an additional monitoring tool to release loads that do not contain implants.

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Class 5 : Integrating Indicators

• For this additional monitoring the Class 5 Integrating Indicator must be used in the appropriate challenge test pack or Process Challenge Device (PCD). These indicators must now have SVs at 121°C/250°F, 135°C/276°F, and at least one more temperature in between. Also, the SV at 121°C MUST be greater than 16.5 minutes to ensure performance is comparable to BIs in saturated steam.

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Class 6 : Emulating Indicators • Emulating indicators

are cycle verification indicators which shall be designed to react to all critical variables for specified sterilization cycles. The Svs are generated from the critical variables of the specified sterilization process.”

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Biological Indicators

• Biological indicators are recognized by most authorities as being closest to the ideal monitors of the sterilization process because they measure the sterilization process directly by using the most resistant microorganisms (i.e., Bacillus spores), and not by merely testing the physical and chemical conditions necessary for sterilization

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Why Bacillus spores preferred

• Since the Bacillus spores used in biological indicators are more resistant and present in greater numbers than are the common microbial contaminants found on patient-care equipment, the demonstration that the biological indicator has been inactivated strongly implies that other potential pathogens in the load have been killed.

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Biological Indicators directly Monitor the sterilization Process

• Biological indicators are the only process indicators that directly monitor the lethality of a given sterilization process. Spores used to monitor a sterilization process have demonstrated resistance to the sterilizing agent and are more resistant than the bio-burden found on medical devices.

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B. atrophaeus spores used for monitoring

• B. atrophaeus spores are used to monitor EO and dry heat, and G. stearothermophilus spores ) are used to monitor steam sterilization, hydrogen peroxide gas plasma, and liquid per-acetic acid sterilizers. G. stearothermophilus is incubated at 55-60°C, and B. atrophaeus is incubated at 35-37°C. Steam and low temperature sterilizers (e.g., hydrogen peroxide gas plasma, per-acetic acid) should be monitored at least weekly with the appropriate commercial preparation of spores

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Daily use of Biological Indicators

Recommended • If a sterilizer is used

frequently (e.g., several loads per day), daily use of biological indicators allows earlier discovery of equipment malfunctions or procedural errors and thus minimizes the extent of patient surveillance and product recall needed in the event of a positive biological indicator

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Monitoring essential in each load …..

• Each load should be monitored if it contains implantable objects. If feasible, implantable items should not be used until the results of spore tests are known to be negative

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What is New generation Biological Indicator

• The next generation of biological indicator was self-contained in plastic vials containing a spore-coated paper strip and a growth media in a crushable glass ampoule. This indicator had a maximum incubation of 48 hours but significant failures could be detected in ≤ 24 hours.

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What is rapid-readout biological

indicator • A rapid-readout biological

indicator that detects the presence of enzymes of G. stearothermophilus by reading a fluorescent product produced by the enzymatic breakdown of a non-fluorescent substrate has been marketed for the more than 10 years

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Rapid Readout • Studies demonstrate

that the sensitivity of rapid-readout tests for steam sterilization parallels that of the conventional sterilization-specific biological indicators and the fluorescent rapid readout results reliable.

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Super Readout Biological Indicator

• A new rapid-readout EO biological indicator has been designed for rapid and reliable monitoring of EO sterilization processes. The indicator has been cleared by the FDA for use in the United States.

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Many Hospitals Going for Rapid Technology

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How the Read out technology works • The rapid-readout EO

biological indicator detects the presence of B. atrophaeus by detecting a fluorescent signal indicating the activity of an enzyme present within the B. atrophaeus organism, beta-glucosidase. The fluorescence indicates the presence of an active spore-associated enzyme and a sterilization process failure.

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Rapid-readout EO biological indicator •The rapid-readout EO biological indicator can be used

to monitor 100% EO, and EO-HCFC mixture sterilization cycles. It has not been tested in EO-CO2 mixture sterilization cycles. The standard biological indicator used for monitoring full-cycle steam sterilizers does not provide reliable monitoring flash sterilizers. Biological indicators specifically designed for monitoring flash sterilization are now available, and studies comparing them have been published.

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IN INFECTIOUS DISEASES

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References • 1 CSSD CONNECT overview CSSD CONNECT is an Initiative by PCI with

the purpose of spreading awareness about the right practices to be followed in sterile departments in hospitals:

• 2 Health care improving portals on world wide web

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•Program created by Dr.T.V.Rao MD for Medical and Health care workers in the

Developing world • Email

• doctortvrao@gmail.com

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