BACK IN PLAY Low-temperature sterilizers are workhorses of the sterile processing department for getting heat-sensitive instruments back to the OR.

For those complex surgical instruments that can't tolerate the high heat of steam sterilization, you have a growing number of low-temperature alternatives from which to choose. Cycle times is a key concern. Here's how your low-temperature sterilization options stack up by cycle time from shortest to longest:

Let's Stamp Out SSIs, Part 10

This Month: Low-Temperature Sterilization
December: Catheter-Associated Infections

• Peracetic acid. Peracetic acid's 23-minute cycle makes it a good just-in-time sterilization method for heat-sensitive devices you'll use immediately (see "Tips for Integrating New Flash Containers" on page 41).

• Hydrogen peroxide gas plasma. A hydrogen peroxide gas plasma cycle takes 28 to 55 minutes, depending on the sterilizer. Keep in mind that all items must be wrapped and only dry items can be sterilized. These self-contained sterilizers don't need plumbing or exhaust. The multi-use cassettes allow for the correct amount of sterilant to be dispensed with each load. This method has limitations on the length and diameter of lumens of devices to be sterilized, making it less than ideal for flexible endoscopes. Each instrument must be completely dry before it's wrapped in order for the sterilizer to work properly. Wet instruments will cause the cycle to abort. Air-drying each instrument before wrapping helps ensure everything is dry and will reduce the chance of aborted cycles. Remember, the 2 leading culprits of aborted cycles are moist instruments and overloaded units.

• Vaporized hydrogen peroxide. Vaporized hydrogen peroxide sterilizes devices in pouches or wrapped trays at 122 ?F during a 55-minute cycle. It requires no special utilities or venting. Don't use vaporized hydrogen peroxide for polymethyl methacrylate or polycarbonate instruments that will come in contact with the eye.

• Ethylene oxide. The cycle time for ethylene oxide can be 12 hours or more for each load to properly aerate. A sterile processing manager told us that his biggest challenge with EtO sterilization is turnover time. The sterilization time itself is only an hour, but the cycle also requires a 10-hour aeration time. Once the standard for low-temperature sterilization, EtO gas sterilizes at 99 ?F to 131 ?F. It doesn't leave residue on the material surface and has fewer lumen restrictions than other methods. However, EtO is reactive and flammable and poses health hazards that require special handling and training. Some states require special exhaust systems for EtO sterilizers. Instruments in each cycle also need to dry completely.

• Ozone. Although each ozone load is low-cost because there's no sterilant to purchase — the method uses only water, oxygen and electricity — the 4.5-hour run time is a drawback. Because the ozone system creates a vacuum, power tools with oil in them can't run through the system. Tools with oil in them need to be autoclaved or processed in a gravity displacement steam sterilizer.

Key to ensuring the proper use of low-temp sterilizers is creating reasonable expectations in the operating room about how long it takes to reprocess heat-sensitive instruments. "The length of time is of great concern," says Rudolph Gonzales, RN, MSN, CNOR, CRCST, nursing manager at Interim LSU Public Hospital in New Orleans, La. "Where compatible, we may run items in plasma. Still, for rapid use in the OR, peracetic acid is our best option where we don't store items for later use. The best of all worlds is that they be terminally sterilized and be ready on the shelf."

Instrument compatibility
Before you put any device into a low-temperature sterilizer, make sure the manufacturer of that type of sterilizer has validated it. Elaine Geroski, BSN, RN, CNOR, the director of surgical services at Garrett County Memorial Hospital in Oakland, Md., found this out the hard — and expensive — way. When Ms. Geroski switched from the Steris System 1, her rep said the new tabletop sterilizer was compatible with her flexible scopes. Not true, as she found out when the pressure in the sterilizer ruptured a hysteroscope and a choledocoscope (the scope manufacturer let her trade the damaged the scopes in for new ones, she says).

"Look for yourself to make sure they're compatible," says Ms. Geroski. "Review your instructions for use on the equipment you want to sterilize."

COMPATIBILITY CHECK Before you put any device into a low-temperature sterilizer, make sure the manufacturer of that type of sterilizer has validated it.

In an ideal world
What are the characteristics of an ideal low-temperature sterilization process? Marcia Patrick, MSN, RN, CIC, an infection prevention consultant from Tacoma, Wash., cites the following 9 factors:

• High efficacy. The agent should be virucidal, bactericidal, tuberculocidal, fungicidal and sporicidal.

• Rapid activity. Ability to quickly achieve sterilization.

• Strong penetrability. Ability to penetrate common medical-device packaging materials and penetrate into the interior of device lumens.

• Material compatibility. Produces only negligible changes in the appearance or the function of processed items and packaging materials even after repeated cycling.

• Non-toxic. Presents no toxic health risk to the operator or patient, and poses no hazard to the environment.

• Organic material resistance. Withstands reasonable organic material challenge without loss of efficacy.

• Adaptability. Suitable for large or small (point-of-use) installations.

• Monitoring capability. Monitored easily and accurately with physical, chemical and biological process monitors.

• Cost-effectiveness. Reasonable cost for installation and for routine operation.