Can you address the importance of leaving instruments unclamped when they are wrapped in surgery packs for steam sterilization? Also, what is the proper technique for packing instruments for steam sterilization?

Shannan Kost, AS

Boone, NC

Leaving an instrument unclamped allows steam to come in contact with all surfaces in order to render the item sterile. This same principle applies to sterilization using a liquid agent (e.g., Cidex Solution, Cidex OPA [ortho-phthal­aldehyde], peroxyacetic acid), steam, dry heat, or gas (e.g., ethylene oxide). If an instrument is clamped during the sterilization process, the surfaces that touch each other will not come in contact with the steam and therefore will not be sterile.

For proper preparation of pack contents for steam sterilization, the following criteria should be considered:

• The pack must permit air removal and allow the sterilant to contact all surfaces of the instruments in the pack.
• Evaporation of the condensate should be maximized after the steam sterilization exposure time (to avoid "wet packs").
• The pack contents must be kept sterile until the pack is opened for use.
• The pack must allow for aseptic presentation at the time of use.

Other factors that should be considered when constructing a pack are reviewed in the following discussion of how to put together a procedure tray:

• The tray should have a perforated or wire-mesh bottom to maximize sterilant contact and air removal.
• The wrap used should provide a reliable barrier to microbial introduction, dust, and moisture penetration.
• The wrap also should be durable enough to resist tears and punctures during handling and transport.
• An absorbent tray liner can be used to absorb moisture and cushion the instruments. (Huck towels also can be used.)
• The items should be arranged so that like instruments are grouped together. Whenever possible, instruments should be placed in the tray in order of use (taking into consideration the placement of both heavy and delicate instruments).
• Ring-handled instruments can be placed on tray pins or stringers to ensure that instruments with box locks remain open.
• Heavy instruments should be placed on the bottom or at one end of the tray to avoid damaging smaller instruments.
• Sharp or delicate instruments should have protective tip guards that allow for penetration of the steam during sterilization. (Check with the manufacturer to make sure instruments are in compliance.)

In addition, the instruments should be placed in the tray so that the weight is evenly distributed. The tray should weigh no more than 16 to 17 lb. To ensure that a tray's size, density, and metal mass do not interfere with the sterilization of its contents, a biologic indicator should be used. Peel pouches should not be used to hold smaller instruments/items together in a wrapped pack. Neither tape nor rubber bands should be used to hold instruments together because they can interfere with steam and moisture contact with the instruments' surfaces.