A Study for Safe Storage Time for In-house Sterilized Products in a Korean Hospital

멸균품의 유효기간에 관한 연구 - 포장재와 보관환경 중심으로 -

This study was conducted to justify the "prescribed shelf life" currently used in Samsung Medical Center and give recommendations based on scientific data to adopt for safe and cost-effective storage times for sterile goods Since the early 1970's, predetermined expiration dating policy has been used in Korea on all in-house sterilized products like any other countries; six months for the supplies wrapped in polyethylene peel pouches and two weeks for the rest. Recently, however, the studies suggest that current standards for preserving the sterility can be changing. It looks like we unnecessarily have too-short expiration date of sterilized supplies, that is far from being cost effective. Certainly, this research is an exciting project, especially in Korea, and will be leading and contributing to the paradigm shift of the conservative concept of shelf life for sterile supplies in Korean healthcare facilities. The major goal of this study was placed on the measurement of the recontamination time in packs wrapped in all kinds of wrapping materials used in S.M.C and stored in various conditions for periods ranging from three months to six months, and then develop a practical standard of "shelf life" based on the analyzed data. Objectives: To measure and compare the recontamination time of sterile packs among wrapppers and storage conditions, and develop a practical standard for the shelf life and storage conditions of sterile products. Samples and Method: The sterile integrity was investigated of the total 1,440 sterile sample packs containing gauze strip($1.5cm{\times}0.5cm$) we prepared and wrapped in nine wrapping materials (randomized reprocessed linens, linens reprocessed 99 times, linens reprocessed 120 times, new kraft paper, used kraft paper, new nonwoven fabrics, 6-time reprocessed nonwoven fabrics, new polyethylene peel pouches, used polyethylene peel pouches), and stored in four locations(closed cabinet of one of the typical wards, open shelf of one of ICUs, open shelf of separate storage room in ER, open shelf in OR), for three to six months, respectively in 1998. Each type of packs were opened weekly and the gauze strips inoculated into Brewer's thioglycollate broth at $35^{\circ}C$ for seven days. Results: There was no growth found for any types of the pack and storage conditions studied. Discussion: This study was conducted in an attempt to identify the possibility of extending the current shelf life for sterile goods we use in a sense of cost effectiveness. The findings suggest that we could extend our expiration dates, that means we can save a lot of materials and personnel time meeded for resterilizing, outdating, recleaning, wrapping, and reshelving. Then it will initiate a great reform in the field of healthcare in Korea, and now we are looking forward to this valuable revolution. We are going to continue this study and take all steps need to apply this new concept to our practice, and then trying to extend to other hospitals.