Infection Control Today - 07/2000: Event-Related Sterility: Then and Now

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Event-Related Sterility: Then and Now

by Connie Cutler, RN, MS, CIC

Storing sterile packs.

Did you ever hear the one about sterile items discovered 50 years after World War II? The story goes that a nurse found gauze and bandages wrapped in muslin in the basement of a hospital in British Columbia, Canada. The finder surmised that they were probably prepared for shipment to Europe. She took them to the laboratory for testing, and cultures showed no growth.1

Ever since I started in Infection Control almost 20 years ago, I wanted to use event- related sterilization as the method to determine the conditions under which an item is considered to be no longer sterile. It never made clinical sense to pick a magical date after which items would no longer be considered sterile. Illinois finally got the legal ability to change to event- related sterilization. However, this change did not come easily. Many articles were written supporting this procedure, but the Illinois Hospital Licensing Act only allowed date-related sterilization. When it was time for biannual (at that time) Joint Commission on the Accreditation of Healthcare Organizations surveys, the nurse surveyor would asked why we weren't using event-related sterilization. I had to respond that state law did not allow it. She advised that we try to change the law. That is easier said than done.

Then, in 1994, I was selected to be on a task force of Infection Control Professionals whose facilities were members of the Metropolitan Chicago Healthcare Council. This influential group collects data on hospitals and presents programs on health topics. Our charge was to make infection control recommendations to the state for incorporation into the Hospital Licensing Act. This panel's members reviewed the literature on the topic and proposed the change to include event-related sterilization as an additional option. In 1995, the state changed the Hospital Licensing Act to allow hospitals the choice to use traditional time-dated or event-related sterilization. The new wording is as follows:

Designation of shelf-life may be event related if policies and procedures, approved by the Infection Control Committee, address at least the following:

  • Requirements for wrapping, storage, and rotation of sterile supplies.
  • Definition of an event that may cause a sterile item to be suspected of being compromised, such as the package being wet or torn, or the seal being broken or tampered with.
  • Clear direction that final inspection of the package and the ultimate decision to use the contents of the package rest with the clinician.
  • Orientation, in-service, and other follow-up to assure that all necessary staff understand and implement the policies and procedures.2

Many articles promote the safety of event-related sterility. In 1984, one author stated that time-related sterility was archaic.3 An article published in March 1991 described the institution of successful, documented indefinite shelf-life at two hospitals. The first was successful in implementing the change by performing cultures of previously overlooked outdated items from earlier years. These items were cultured and the results indicated no growth. The second facility also used culturing of expiration dated items to convince their Infection Control Committee to change its policy. Both facilities clearly defined the events that could cause loss of sterility and educated the users on these. Those conditions included that the package is not "torn, wet or damaged or suspected of being compromised."4 In other articles, cultures of items also showed no growth.5-6

Savings derive from decreases in labor costs in Central Processing and Operating Room.

A hospital in Milwaukee reported using event-related sterilization as a continuous quality assurance process. This reference concluded that "event-related sterility assurance improves the quality and efficiency of the sterilization process, utilizes fewer resources, assists in inventory control and related costs, increases staff time for patient care, and raises employee morale."7 Another author pointed out that removing items for sterilization after the expiration date had been passed took sterile instruments out of circulation when they could have been used for patient care.8 In this day of decreasing healthcare reimbursement, purchasing extra instruments to allow for resterilization of sterile instruments just doesn't make sense.

What type of wrapper is best for event-related sterilization? In an article about long-term storage effects, Klapes addressed the type of wrapper that would have the lowest contamination rate. The differences between four types (peel pouches, two two-ply new reusable non-barriers, two nonwoven barriers, and two two-ply used reusable non-barriers) was not statistically significant in a storage period of 50 weeks.9 In another article, Belkin concluded that "a perfect wrapper would be one that is impervious to extraneous microbes, liquid-proof, free of holes, free of lint, free of memory, strong enough to resist punctures and tears, and economical to use."10 Unfortunately, such a product would not allow steam to penetrate for sterilization.

In this era of managed care contracts, any opportunity for cost-savings is appreciated by administration. The estimated savings from using event-related sterility procedures ranged from $2,000 per year in 1990 to $10,000 per year in 1992. Savings derive from decreases in labor costs in Central Processing and Operating Room, decreased laundry costs, fewer sterilization loads, and fewer supplies such as pouches.1 Other cost analyses have shown similar results.5 Another facility estimated a $10,000 savings in 1995 in a hospital performing 600 cases/month without including costs of staff time in "gathering, re-wrapping, reprocessing and reshelving the items."6 Another article quoted savings up to $25,000.11

Obstacles to Implementing Event-Related Sterilization

What obstacles have facilities faced when proposing the change to event-related sterilization? One author lists the following 10 challenges:

1. Overcoming resistance to change.

2. It takes too much time and effort to change.

3. How to work with state or local laws that still require expiration dates on hospital packages.

4. The hospital isn't comfortable with its storage practices.

5. Gaining control over transportation and handling procedures.

6. Uncertainty about whether packaging material will hold up in event-related sterility environments.

7. Fear of problems with the Joint Commission.

8. Writing a policy takes time and knowledge about the new system.

9. Establishing an effective labeling system.

10. Uncertainty about how long it will take to convert to an event- related sterility maintenance program.11

In conclusion, Advocate Health Care (Oak Brook, Ill) faced many of the above issues and came out with a workable event-related sterility program. With a little time, a little patience, and a little science thrown in for good measure, other facilities can create similar programs. Be a champion for cost savings at your institution by implementing event-related sterilization.

Connie Cutler, RN, MS, CIC, is the Coordinator of Infection Control at Advocate Health Care (Oak Brook, Ill) and Manager of Epidemiology and Infection Control at Advocate Lutheran General Hospital (Park Ridge, Ill).


1 Small D. A timeless tale: converting from date-related to event-related resterilization of supplies. Leadership in Health Services. 1995;4(2):40-41.

2 Illinois Administrative Code. Hospital Licensing Requirements. 1995;Section 250.1090.

3 Mayworm D. Sterile shelf life and expiration dating. J Hosp Supply, Processing, Distribution. 1984;Nov/Dec:32-35.

4 Donovan A, Turner DW, Smith A. Successful, documented studies favoring indefinite shelf life. Mater Manag Health Care. 1991;9(2):34-40.

5 Schroeter K. Two studies of event-related sterility. Materials Manage. 1995;4(2):44,46.

6 Lamb J, Foster S, Henderson E. Significant savings achieved by implementing event related outdating. 1996;14(3):12-14.

7 O'Connor LM. Event-related sterility assurance. Surg Technologist. 1994;26(1):8-11.

8 Bell MA. Hospital uses team approach to improve processes, reduce costs. AORN J. 68(1):68-72.

9 Klapes NA, Greene VW, Langholz AC, Hunstiger, C. Effect of long-term storage on sterile status of devices in surgical packs. 1987;8(7):289-293.

10 Belkin NL. Should shelf-life policy be determined by events or time? Today's Surg Nurse. 1996;18(2):15-18.

11 Morrall K. Ten challenges to event-related sterility programs. Materials Manage. 1995;4(9):60,62.

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