277 - Shelf life of reprocessable medical devices: a scope review on the application and limitations of microbiological testing

Description: Problem/

Purpose: several institutions choose to use an arbitrary expiration date based on microbiological sterility testing.
Literature review: Studies argue that maintaining the sterility of surgical instruments depends on the integrity of the packaging, storage conditions, and handling.
Search Question: What are the existing evidences on the use of microbiological testing to determine the shelf life of sterilized reusable medical devices in Central Sterile Supply Departments (CSSD)?
Conceptual Framework: Scope review conducted according to the Joanna Briggs Institute methodology.
Methodology: With the help of an experienced librarian, descriptors and Booleans were combined to develop the search strategy. The search
included the PubMed, Cinahl, Scopus, Embase, and Cochrane databases, the Virtual Health Library, as well as gray literature through Google Scholar and Proquest. The selection and analysis of studies was performed independently by two researchers, according to the inclusion criteria. A third reviewer was called in to resolve any disagreements and make the final decision.
Data Analysis: Data extraction from the selected studies was performed manually using a spreadsheet, including details on the population, methodology, and significant outcomes. The report was presented in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews (PRISMA-ScR). The search results were fully reported at the end of the review and presented in a PRISMA flow diagram. The findings were presented in table, graph, and text form.

Results: 2,256 records were found. After exclusions, 1,380 underwent title and abstract analysis and 96 with complete reports, with 36 studies
being included. A single literature review was found. Most (55.5%) were published between 2000 and 2015, were quasi-experimental (52.7%), originated in the Americas (58.3%), and were published in English (69.4%). Twenty-two (57.8%) sterilized the samples in a steam autoclave, and eleven (28.9%) did not specify the sterilization method. A total of 106 packaging analyses were performed: 41.5% paper, 35.8% fabric, 14.1% non-woven, 6.6% boxes, and 1.8% other unspecified. The shortest shelf life was two days, the longest was 11 years, and the most prevalent was 180 days. Regarding the sterility test results, 54.2% were positive and 45.7% were negative. Only seven (19.4%) publications presented all the information on the microbiological test. Of the positive studies, nine (47.3%) reported the possibility of test contamination as an inherent or accidental result related to the seeding technique, and three studies considered their samples sterile due to this fact. The main microorganisms found were cocci, Gram-positive bacilli, and filamentous fungi.

Conclusions: The evidence indicates that the microbiological sterility test should not be applied to determine the sterilization shelf life of reusable medical devices, once that studies have indicated that event-related sterility is more appropriate for maintaining sterility than defining a shelf life based on microbiological testing.
Perioperative nursing implications:The adoption of event-related sterility and the avoidance of microbiological testing to determine shelf life result in savings of financial, material, and human resources, in addition to contributing to infection prevention.