Sterilization Guide PDF

ALL YOU NEED TO KNOW ABOUT CENTRAL STERILE SUPPLY DEPARTMENT Sterilization By Talal Albudayri 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,...

ALL YOU NEED TO KNOW ABOUT CENTRAL STERILE SUPPLY DEPARTMENT Sterilization By Talal Albudayri 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.  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  moist heat sterilization using steam under pressure WHEN IS STERILIZATION REQUIRED? it is more reliable and can be THIS IS BASED ON THE SPAULDING ADVANTAGE more effectively monitored and CLASSIFICATION OF RISK ASSESSMENT. validated. STERILIZATION IS REQUIRED FOR RMD, MEDICAL DEVICES THAT COME INTO CONTACT WITH A BREAK IN THE SKIN this method is not suitable for OR MUCOUS MEMBRANE OR ENTER A STERILE BODY CAVITY. DISADVANTAGE items that are damaged by heat or moisture,  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.  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.  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).  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.  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.  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.  A typical cycle consists of: Load pre-conditioning—vacuum and humidification Sterilizing gas exposure Gas exhaust and air purge  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. 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. Ethylene Oxide (EO)  Sterilization Validation Validation establishes documented evidence providing a high 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 (contents) and documentation of the results Assuring all components of the process such as proper cleaning, functionality, packing, wrapping are met Proper protocol management  Steam Sterilizer Testing Routine testing of sterilizers should be performed daily, weekly, quarterly and yearly as per ISO 17665.  Daily Bowie-Dick test for steam penetration (also known as air removal test). 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  Yearly All the above plus Steam quality tests --Steam superheat -Non-condensable gas --Steam drynes -s –Endotoxins Thermocouple test Testing of dry heat sterilizers Biological indicators Chemical indicator  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 and humidity Biological indicators Chemical indicators  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. 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.  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  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.  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.  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  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  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 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. Steam Sterilization: Advantages and Disadvantages  IUSS System (flash sterilization) Immediate use steam sterilization (IUSS) 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 operate at 134oC for 3–10 minutes resulting in wet and very hot medical devices in the operating room environment. Flash sterilization is of: non-porous and/or non-hollow surgical instruments in an unwrapped condition. usually located in the operating room example a dropped instrument when no alternative is available.  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 andof staff thesafety during transfer sterilized items from the sterilizer to the Items are needed for use immediately following point of use soon as the device cools so as IUSS, as not to burn the patient records maintained Sterilizers are routinely tested prior to use and appropriate  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  IUSS Recommendations Restrict use to emergencies, such as unexpected surgery, or dropped devices In most emergency situations, the risk/benefit ratio IUSS-is low enough to justify the use of 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  Dry Heat Sterilization The dry heat method may be used for glassware and metal items, heat stable powders and non- aqueous liquids like paraffin. 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. his process does not use steam so the typical times required for sterilization are much longer.  The typical time and temperatures used are: 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  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 peroxideof the hydrogen and generation of the plasma for a defined sterilization time, followed by aeration and venting. Thank you! By Talal Albudayri