As more types of procedures have moved to outpatient settings, the need for gentler sterilization that works on complicated internal parts has grown. For this reason, most outpatient surgery facilities have at least two types of sterilizers - a steam autoclave and a low-temperature method.

"Many devices can't withstand the temperature that autoclaves require for sterilization. Then the facility must look to other technology that operates at a lower temperature," says Zory Glaser, PhD, MPH, a former FDA official who is now an infection control consultant in Baltimore, Md., and Washington, D.C.

In this overview, we'll discuss increasing options in low-temperature sterilization, enhancements to steam sterilizers, and improved data capture for cycle verification and documentation.

Pre- and post-vacuum sterilizers
Manufacturers are gearing pre- and post-vacuum sterilizers, long a staple at hospitals, for the outpatient market. Pre-and post-vacuum models are said to sterilize and dry instruments better and offer quicker instrument turnaround. Air prevents steam from reaching proper killing temperature; in pre- and post-vacuum, a pump pulls air out of the sterilizer chamber.

"Pre- and post-vacuum models typically cost more than gravity-based sterilizers, but the facility recoups the cost difference in a higher grade of sterilization and faster turnaround," says Tuttnauer's Frank Krol.

Tuttnauer's EHS Series Pre and Post Vacuum tabletop models provide rapid (28-minute) "dry-to-dry" cycles. The EHS series use a continual mineral-free water supply, so the chamber doesn't need to be filled.

Scott Blair, purchasing director for Surgery Center Services of America, calls the EHS Series Pre and Post Vacuum sterilizer "a solid machine for smaller budgets," that's faster and more robust than other small units and performs similarly to larger units. Pre-vac lets you process wrapped packs with complete drying.

He notes that running EHS autoclaves requires less staff time compared to other tabletop sterilizers, and that your center will need fewer instrument sets due to the quicker turnaround time. Because the product is relatively new, Mr. Blair has had difficulty locating trained service technicians near his client facilities.

Getinge Castle's 400HC/500HC Series, introduced last year, offer a pre-vacuum cycle for wrapped and unwrapped items. Getinge Castle's Chip Moore says the sterilizers are earning a reputation for "work, work and work." The 400HC/500HC Series have up to 22 cycles that can be configured for individual processing needs. The rectangular door openings (17.5" x 17.5" and 21" x 21") let you process large items. Instruments may be wrapped or unwrapped, and each load shelf has the same width for loading; the user can adjust shelf height in increments of 2.5 inches.

The Amsco Century Medium Steam Sterilizer from Steris offers a pre-vacuum configuration or steam flush pressure pulse (SFPP) configuration. Either option will condition loads before sterilization. The high-volume sterilizer is programmable, automatically checks and documents cycle data and provides a printout for record keeping, says Steris. The internal battery retains cycle memory if a power failure occurs during a cycle, and restores proper cycle completion when power is restored.

Jan James, the central sterilizing director for Medical College of Ohio, says her department prefers the Century Medium over previous Steris models and other steam sterilizers. "The LCD and printout are easier to read and they're at eye level. We also like the oval shape of the interior. If we have a tray that hangs out a half-inch, we can put it in at the regular angle on the shelf. We can put more in the sterilizer, and that's important to us. We use our sterilizers 24/7," says Ms. James.

Pure steam, a "cleaner" form of sterilization used by laboratories and pharmaceutical companies, is now available to the surgical market. By providing steam that is free of mineral deposits, this technology eliminates buildup on chamber walls and deposits on instruments and hinges, possibly reducing instrument repair and replacement. To create pure steam, the facility must supply de-ionized water, fed into a steam-to-steam heat exchanger or through an advanced filtering system - at an additional cost of $3,000 to $15,000. Pure steam requires a full stainless steel chamber (pure steam will draw minerals if sent through a non-stainless chamber or pipe).

Belimed offers a full stainless chamber in its VS1 and VS2 models, which come in three sizes for outpatient facilities. The VS1 and VS2 models may be used as pre-vacuum or flash sterilizer. An electromechanical vacuum pump pulls a more efficient vacuum, providing more complete, quick drying. Belimed notes that these models have a very large capacity for such a small footprint when compared to older technology (the unit can accommodate four full-sized container boxes or similarly sized wrapped trays). If house steam is not available, the unit can be ordered with a built-in steam generator. These models offer integrated data management that reduces paperwork and paper storage.

Piedmont Hospital in Atlanta, Ga., purchased a pure steam sterilizer from Belimed about six months ago. Nurse Manager Faye Nowland, RN, MBA, says her facility had a whole laundry list of features they were looking for, including service, dependability, operational cost, ability to use pure steam, quietness, automatic unload feature, decreased dry time, increased throughput, automatic door closure, stainless steel interior, very little maintenance and easy access for service personnel. "I'm extremely satisfied and the staff really loves it. We've already ordered a second one," says Ms. Nowland.

This month, Midmark introduces the cost-effective M9 and M11 tabletop sterilizers, which let the user program or modify sterilization times.

About a year ago, SciCan introduced Quantim (lists for $5,600), a tabletop steam sterilizer with an integrated boiler so water does not have to be heated in the chamber. This reduces corrosion or damage to the chamber. The water is discarded after each cycle (called a single-water or open-water feature). During the drying cycle, a vacuum pump lets you keep the sterilizer sealed.

SciCan also offers Statim, an open-water steam sterilizer that provides a complete, unwrapped cycle in six to nine minutes. Statim features a cassette you can use to transport instruments to the sterile field. Statim comes in two sizes, with the larger size offering an extended cassette for sterilizing rigid endoscopes.

EtO Sterilizers
This lower-temperature sterilization method has been used for more than 40 years in the medical device manufacturing industry and is widely used in healthcare facilities, says Dr. Glaser, a member of the Association for the Advancement of Medical Instrumentation (AAMI) Standards Committee. "The entire disposable medical equipment industry was based on the fact that items could be EtO sterilized, shipped to the user and, assuming package integrity, would remain sterile until the item was used," he notes.

The author of several published studies comparing EtO to other types of sterilization, Dr. Glaser believes the method has many benefits for medical facilities: "A sterilizer must be reliable, economical, easy to operate and maintain, and be available in a variety of sizes and forms. EtO fits that profile."

He notes that some critics call EtO a toxic chemical, but there are risks to working with other sterilization methods as well.

"Users get burned with steam, and other disinfectants and sterilants are toxic, too. When manufacturers say their disinfectants and sterilants are not toxic, they are not recognizing that to be effective, a disinfectant or sterilant must be microbiologically active, which generally implies it's also toxic to humans. We have learned to work safely with EtO and other toxic substances," says Dr. Glaser.

The Anprolene AN-74i from Andersen Products is a new tabletop unit for office-based surgery and surgery centers. Andersen calls it the gentlest sterilizer on the market because it operates at the lowest temperature and uses the smallest amount of EtO compared to the competition.

Using EtO at room temperature, the AN-74i works using a plastic sterilization bag filled with the items to be sterilized and an ampoule of EtO. When the ampoule is broken, the sterilization cycle begins. At the end of the cycle, the bag is aerated inside the sterilizer unit. The AN-741 is a single-load system. Tonya Jethro of the Hubbard Plastic Surgery Center in Virginia Beach, Va., has used the AN-74i for almost two years. She says the unit is very reliable and helps the center save money by safely sterilizing disposable items for reuse.

Later this year, Anderson will introduce the Anprolene AN-2000, a double-wall design that is a bit quieter than the AN-74 and will sell for less than $4,000. The AN-2000 has a textured powder coat finish, an improved air filtration system and will be available with an optional EtO abatement system. Andersen also offers the EOGas system, a multi-load EtO sterilizer that lets you add new product loads to the sterilizer while other loads are being sterilized.

Chemical systems
High-level disinfection for endoscopes gets some new options this year. In March, the FDA gave permission to Advanced Sterilization Products to recommend a five-minute processing time for its CIDEX OPA Solution. When used in automatic endoscope reprocessors at a minimum of 25'C (77'F), processing time may be reduced from 12 minutes to five minutes. ASP says the reduction makes CIDEX OPA Solution the fastest non-glutaraldehyde, high-level disinfectant available for medical device reprocessing.

"Surgery centers can schedule more procedures each day and eliminate redundant instrument inventories. CIDEX OPA is also a non-glut solution, which is gentle on instruments (non-corrosive unlike peracetic acid), so it cuts down on instrument repair costs," says Lori Haycox of Advanced Sterilization Products.

Medical facilities can also manually process instruments in CIDEX OPA Solution, although a 12-minute soak time at room temperature (20'C) should be observed. CIDEX OPA Solution requires no activation or mixing and has a 14-day reuse life, a 75-day open-bottle life and a two-year shelf life.

This August, Sterilox Technologies will introduce Sterilox Liquid Chemical High Level Disinfectant in the U.S. Sterilox will be generated on-site in the surgery center or hospital for disinfecting heat-sensitive medical devices. Sterilox is made from saline solution through a patented electrolysis process. The solution is a diluted mixture of mild oxidants (principally hypochlorous acid) at nearly neutral pH.

"Unlike glutaraldehyde or OPA, Sterilox is non-toxic, non-irritant and not a hazmat," says Joe Rafferty, Sterilox the vice president of U.S. sales and marketing. Mr. Rafferty says Sterilox shortens the instrument turnaround time. Instruments must be soaked in Sterilox, an oxidizing agent that has no known resistant microorganisms, for 10 minutes.

The facility must obtain a Sterilox generator, which can be leased for $15,000 a year. There will be two generators for outpatient or office use in 2003, the US-1 and the 2008 (which has a smaller footprint). The generator pumps Sterilox directly into an automated endoscope reprocessor as needed, so staff members never have to handle the solution. Sterilox generators can be controlled to pump Sterilox directly into a blue bucket or dilator tray.

The solution is used only once and then dumped to waste, says Mr. Rafferty: "Each patient gets a scope that has been disinfected with full-strength solution. Some of the solutions on the market now are used literally hundreds of times before disposal. It has been compared to taking a bath in someone else's - or quite a few someone else's - bath water."

Before you buy
So how do you tell if you need to replace a sterilizer or add one to your clean room?

"Determine if the instrument processing system is slowing down patient flow through the facility," says Chris H. Miller, PhD, a professor of microbiology at the Indiana University School of Dentistry. "If the demand for clinical care increases, consider a larger or second sterilizer. If instruments are rusting badly in steam, consider a dry-heat sterilizer, which does not cause corrosion of instruments and produces dry packs at the end of the cycle (but has a longer cycle time than steam)."

Dr. Miller says you should consider:

• Reliability. Ask the manufacturer or vendor for references of healthcare facilities that use the model in which you're interested. Find out about the availability of maintenance.
• Chamber size. Purchase the largest you can afford so work flow won't be hampered.
• Ease of operation. "One-touch" operation is convenient, but if non-standard loads will be used, make sure the unit has sufficient flexibility to perform those special runs.
• Dry cycle. Look closely at this if you're looking at a steam sterilizer.