This disclosure relates to reducing the incidence of water remaining on steam sterilized packages in a medical setting.
Items used in medical settings such as gowns, sheets, drapes, and instruments used during surgery or other aseptic procedures are used on a daily basis. If these items are not received from a manufacturer in a sterile state, it is necessary for the medical facility to sterilize them before use. If these items are not disposable and are used more than once, it is required that they be sterilized prior to reuse. To sterilize medical items, they are normally first packaged within a protective sheet material wrap and then subject to the steam sterilization procedure. Occasionally, packages emerge from the sterilization process with moisture visible on the wrap. If this occurs, the tray must be rejected.
It is also important to maintain the sterility of the items inside the sterilized, wrapped package until the package is opened. Therefore, a wrap must be able to resist the penetration of bacteria, and must act as a filter to particles that can carry bacteria. Bacterial filtration efficiency (BFE) is a measure of how easily bacteria can pass through the sheet material used to wrap the medical items. A higher BFE indicates that the wrapped, sterilized items should remain bacteria free for a longer period of time than similar sterilized items wrapped with a lower BFE wrap material.
Appropriate protective sheet material includes those as shown, for example, in U.S. Pat. No. 5,635,134 to Bourne, et al., which discloses a multi-ply sterilization wrap that is formed by joining one or more sheets of sterilization wrap (e.g., two separate sheets or one sheet folded over) together to form two similarly sized, superposed panels that allow convenient dual wrapping of an article. As another example, U.S. Patent Publication No. 2001/0036519 by Robert T. Bayer discloses a two ply sterilization wrap that is formed of a single sheet of sterilization wrap material that is folded to form two similarly sized, superposed panels that are bonded to each other. As yet another example, U.S. Patent Publication No. 2005/0163654 by Stecklein, et al. discloses a sterilization wrap material that has a first main panel and a second panel that is smaller than the main panel. The second panel is superposed and bonded to the central portion of the main panel such that it is contained entirely within the main panel to reinforce the main panel and/or provide additional absorbency. U.S. Pat. No. 8,261,963 to Gaynor, et al. discloses a multi-panel sterilization assembly that includes a barrier panel composed of a permeable sheet material having barrier properties, panel attachment means for securing the barrier panel into a package; and a fold protection panel. The barrier panel includes: a first surface and a second opposing surface; a first end generally defining a pre-determined fold line; a second end opposite the first end; a first edge that is generally perpendicular to the pre-determined fold line; a second edge that is generally opposite the pre-determined fold line; and a third edge that is generally perpendicular to the pre-determined fold line. Sterilization wraps may also have a single ply only and these are suitable for use with this disclosure.
Sterilization wraps are commonly made from non-woven materials made by the spunbonding and meltblowing processes and are often electret treated to increase the bacterial filtration efficiency. Electret treatment is described, for example, in U.S. Pat. No. 5,592,357 to Rader, et al.
Items subjected to steam sterilization can sometimes emerge from the sterilization process still containing visible water. These water-containing steam sterilized packages are referred to as “wet packs” and require re-sterilization, costing the medical facility time and money. Reduction in wet packs while maintaining an acceptable BFE level is highly desirable.