Understanding Event-Related Contamination

If you still affix an expiration date to packaged instruments after you sterilize them, it may be time to rethink. The loss of sterility is event-related, not time related. All the experts now agree that a device properly packaged and stored will stay sterile unless and until an event occurs to compromise its sterility.

In this, the first installment of Infection Prevention, I'll explain what those events are and how to avoid trouble because of them. Broadly speaking, there are only four.

Event #1: Moisture
If you are steam sterilizing, you are using packaging materials that are permeable to moisture - and moisture is one means of providing a pathway for bacteria to enter your package. Bacteria have great difficulty moving, multiplying or even surviving on dry surfaces, but add a little moisture and they can do all three. If your packaging admits moisture, you must be especially careful about where you store your sterile items. Do not store them under or next to sinks. Be particularly careful when cleaning sterile storage areas; leave the areas dry, and do not store sterile products on shelves that can collect moisture.

If controlling the environment around your stored sterile products is a problem, an advisable solution is to wrap your sterile packages in plastic that is impervious to moisture of any kind.

A couple of notes about this event: First, do not worry about condensation inside a sealed package. Unless it penetrates the barrier and provides a pathway for bacteria to enter the package, the device will remain sterile.

Also, do not worry about high humidity (a relatively rare animal inside a surgical facility) unless it is severe enough to result in condensation on the surfaces of your storage area.

Be careful handling packages right out of the steam sterilizer. They are hot, and since hot air will contain more moisture than cool air, allow them to cool down to room temperature before moving them to metal shelving.

Event #2: Dust
Dust is another transport vehicle for bacteria. The best way to protect against this bacterial medium is to use disposable or high-quality reusable wrappers. If you are employing reusable wrappers, remember that they lose some of their barrier properties each time they are laundered. Their longevity depends on what was packaged, how tightly it was wrapped, how much detergent was used, how hot the rinse water was, and other factors. It's critical to count the number of uses and meticulously inspect them for holes and areas of weakness before each use.

It's also a good idea to control your storage environment to minimize dust and air movements that can promote dust infiltration. Here are some ideas:

- Do not allow extraneous people in the storage area.
- Protect non-woven and linen-wrapped packages during transport-never transport them while uncovered.
- Rotate products on the "first-in, first-out" system, so that you minimize the time that products can sit on a shelf and collect dust.
- If you can only store products in areas of high activity, wrap them in plastic or store them in closed cabinets.

Event #3: Damage
Before using any sterile item, always examine the packaging for evidence of tears or other damage. Keep in mind that the occurrence of an event does not necessarily mean the contents are no longer sterile. For example, an item that is accidentally dropped on the floor does not automatically become non-sterile. It depends on the product, the packaging material, the distance it fell, what it fell into, and any number of relevant issues. A large instrument tray wrapped in cloth that falls six feet to the floor certainly needs to be opened, examined for internal damage and damage to the wrapper, and resterilized. However, a plastic bag filled with sterile cotton balls, or a pack of towels double wrapped in a disposable non-woven cloth, do not warrant the same caution.

It was once thought that dropping a package would result in an implosion of accumulated bacteria-laden dust into the package. Don't believe it - that's one of the many sterility myths that still pervade some health care facilities.

Event #4: Tampering
This should be an obvious one. Wrap all your products in tamper-proof packaging. Do not use any packaging that can be opened and re-closed. When tape is used to seal a package, tear the tape, don't peel it off when opening the package.

By remaining aware of the four events that compromise sterility and following these simple rules, you can be assured that the products you sterilize will be sterile at the most crucial time - when you use them on your patients.

A note to Outpatient Surgery's readers: The future value of this column will depend upon how well I am able to meet your needs, answer your questions, and help you save time, money, and resources by eliminating wasteful practices while improving the quality of your services. To ensure that I meet these needs, I need your feedback and questions concerning the infection prevention issues surrounding the use of equipment and supplies in your facility. Please fax me at 610-240-4919, e-mail me at [email protected], or snail-mail me at Outpatient Surgery Magazine, 3 Beryl Road, 2nd Floor, Paoli, PA 19301.

Dan Mayworm is the former president of Mayworm Associates, Inc. and publisher of The Journal of Healthcare Resource Management and Infection Control & Sterilization Technology. He is the former president of Tower Products, Inc., a manufacturer of packaging materials for the medical device industry. Mr. Mayworm has served as president of the Health Industries Association and as an executive committee member of the Health Industry Manufacturers Association, and has given expert testimony before both the House and Senate subcommittees.