Flash sterilization is rather an old term. Recent guidelines put out by a multi organisation group prefer to use the term Immediate Use Steam Sterilization or IUSS. IUSS or Flash sterilizers are most often small steam sterilizers that are located as close to the point of use as possible. Most OR units have at least one in the sterile core area. These sterilizers often use Gravity displacement air removal, but there are many that can also run a Pre-Vacuum cycle.
IUSS sterilization can be defined as: The emergency sterilization of an unwrapped item intended for immediate use. This definition can be a challenge for busy OR and Ambulatory Care staff who may want to have many items flashed far in advance of a procedure to save time. MDRD technicians, or nurses on the unit can be called on to provide these flashed items and we need to be confident that we “know the rules” of flash sterilization.
Health Canada Guidelines, CSA standards, as well as many professional organisations such as AORN have stated that IUSS sterilization must only be used in emergency situations, where the time it would take to process an item through a full, wrapped goods, sterilization cycle might put a patient at risk. For example, if an item is dropped on the floor during an operation and there is not another one to replace it, then flash sterilization would be appropriate.
IUSS sterilization must not be used for:
- Implantable equipment or devices like hip prosthesis or bone screws and plates. These devices remain in the body. Infections caused by contaminated implants can be very dangerous for the patient and very difficult to treat.
- Providing enough instrumentation for multiple procedures. If a facility does not have enough instruments to finish all scheduled procedures they should not rely on flashing to provide instrumentation.
- A surgeon’s personal instruments. Procedures should be scheduled to allow these types of instruments to be sterilized in the MDRD.
- Borrowed or loaner instruments. These instruments should arrive in time to be sterilized in the MDRD.
- Complete sets and power equipment unless patient safety is at risk. These items are very complex and can be difficult to adequately sterilize in the IUSS sterilizer.
IF the flash sterilize cycle works then why can’t we flash implants and complete sets?
IUSS or Flash sterilization uses just the sterilize portion of a steam cycle. The items are not wrapped so there is no need for a dry time. As well, the small size of the sterilizer, and lack of packaging or wrappers means that Pre-Vacuum air removal is not necessary; Gravity alone will remove air in the small chamber. Items are exposed to pressure and steam at temperatures of 132ºC (270ºF) to 135ºC (275ºF) for a specific time. So all the necessary requirements for sterilization are met, what is the problem?
IUSS sterilized items are indeed sterile, as defined by all the standards we work with, up until the time we open the sterilizer. The efficacy of the flash process is not in question. The ability to safely deliver the unwrapped item to the sterile field without contaminating it is the problem. Even with the introduction of flash sterilize containers we still have to question whether we can maintain sterility with out packaging. Because so many things can go wrong during transport, best practice states that flash sterilization should only be used as a last resort. This practice cuts down the chance that contaminated items will be used on patients.
We must also be aware that cleanliness is vital to successful sterilization. If an item is not properly cleaned it cannot be said to be sterile no matter what method we use. IUSS sterilization is just as dependent on the cleanliness of items. How do we decontaminate items that are to be flashed? Items must be decontaminated and inspected using the same guidelines we use in the MDRD:
- Transport items carefully in a covered container to a properly ventilated decontamination area separate from clean or sterile areas.
- Following manufacturer’s instructions, and using approved detergents, fully clean and carefully rinse the item. All scrubbing must be done under water to avoid splashing and aerosolization. Full and correct PPE must be worn for this process.
- We must be careful to avoid cross-contamination of the cleaned item – do not place a clean item on a dirty counter or towel.
- Inspect items carefully before sterilization. Flush lumens with sterile water before sterilization. Position cupped surfaces so that they will not trap air or water during sterilization. Open all items as fully as possible to allow steam penetration.
We must think of sterilization as an entire process, involving transport, cleaning, inspection/assembly, handling and possibly storage, as well as the application of a sterilization method.
Guidelines for IUSS Sterilization Parameters.
After proper decontamination and inspection items are ready to be flash sterilized. We can divide most surgical devices into Porous and Non-Porous items.
- Porous items are those that have lumens or multiple parts. Rubber or plastic items are also considered to be porous.
- Non-porous items are simple instruments with no lumens or multiple, complicated parts. If we have Porous and Non-Porous devices in the same load we must treat it as a Porous load.
Gravity Displacement air removal – the most common flash method.
Open container – the items just sit in an open pan
- For Porous items we need a sterilize time of 10 minutes at a minimum of 132ºC (270ºF). This allows for the removal of air from, and the penetration of steam to, all areas of the item.
- For Non-Porous items a time of 3 minutes at a minimum of 132ºC (270º) is standard.
If using an open container for flash sterilization we must be very careful when we open the sterilizer door. The person who removes the open pan from the chamber should be wearing a surgical mask, sterile gloves and gown and handle the open container with a sterile towel. Please refer to your facility’s procedures when using open container flash sterilization.
Closed container – a common one is the “Flash Pak”
- For Porous items a time of at least10 minutes at a minimum of 132ºC (270ºF). Some manufacturer’s instructions will require more exposure time for certain complex items.
- For Non-Porous items a time of 6 minutes at a minimum of 132ºC (270ºF) is recommended. This is slightly longer than the time in an open container to allow for the time it takes to heat up the inside of the Flash Pak.
Pre-Vacuum air removal.
Although not as common as the Gravity Displacement method, Pre-Vacuum air removal is possible in newer flash sterilizers. The temperature parameters remain the same as do most of the sterilize times; however it is possible to flash sterilize some Porous items in a shorter amount of time because of the faster and more complete air removal that Pre-Vacuum offers.
Always consult instrument and sterilizer manufacturer’s instructions regarding sterilize times and methods.
Monitoring the IUSS Process
As with all sterilization methods we must carefully monitor the process to ensure that all parameters are met:
- Chemical Indicators must be included with each cycle, preferably placed close to the item being sterilized. Many sites now use a small, individual Class 5 integrator for each load.
- Biological Indicator tests must be used once per day on each type of cycle that the sterilizer is capable of running. Please consult your department’s policies for current practices.
- Mechanical monitoring is very important for Flash Sterilization. Flashed items are used immediately and we must carefully check all gauges, LED panels and printout tapes to ensure that all parameters have been met – time, temp/pressure, and steam pressure. We must document the name of the item, the area or room in which it will be used, and in many facilities, the name of the patient it will be used on. As with all sterilization records in SPD, this documentation must be kept for 7 years (in Fraser Health).
- If you use a Pre-Vacuum cycle for IUSS Sterilization, you must perform a daily air removal test (Bowie Dick) on your sterilizer.