Holdridge Julie A, Nichols Madison S, Dupont William D, Jones Carissa P, Shuster Katherine A
Department of Pathology, Immunology, and Microbiology, Vanderbilt University Medical Center, Nashville, Tennessee, and Division of Animal Care, Vanderbilt University Medical Center, Nashville, Tennessee.
Division of Animal Care, Vanderbilt University Medical Center, Nashville, Tennessee.
J Am Assoc Lab Anim Sci. 2021 Nov 1;60(6):700-708. doi: 10.30802/AALAS-JAALAS-21-000047. Epub 2021 Nov 8.
One strategy commonly employed for rodent surgeries is a "tips-only" surgical technique, which restricts the surgeon to using only the sterile working ends of the surgical instruments to manipulate the surgical field and sterilizes instrument tips with a hot bead sterilizer between consecutive rodents. Despite the common use of the "tips-only" technique, research is lacking on the number of sequential surgeries for which the same set of hot bead-sterilized instruments can be used before introducing bacterial contamination. We performed serial mouse surgeries using the "tips-only" technique under 3 different conditions (aseptic, fur contamination, or cecal contamination) and assessed aerobic bacterial growth before and after each round of hot bead sterilization. Instrument tips showed an increasing probability of contamination of at least one instrument in a series of consecutive surgeries. The probability that all surgical instrument tips in the series were sterile after hot bead sterilization fell by 4% for each surgery involving inadvertent or fur contamination and by 11.5% for each surgery with contamination for all surgical types combined (including entering the gastrointestinal tract). Based on our results, hot bead sterilization is not adequate for surgeries associated with gross contamination. Under our experimental conditions and assuming independence of outcomes between consecutive surgeries, up to 5 surgeries associated with minor or inadvertent contamination could be performed in series with a probability higher than 80% that all instrument tips were sterile for all surgeries. A case-by-case risk assessment should be conducted to derive institutional guidelines for the maximal number of surgeries that can be performed in sequence using the "tips-only" technique with hot bead sterilization of the same set of surgical instruments between surgeries. Full sterilization of instruments after every surgery provides the greatest confidence in maintaining sterility.
一种常用于啮齿动物手术的策略是“仅使用尖端”手术技术，该技术限制外科医生仅使用手术器械的无菌工作端来操作手术区域，并在连续的啮齿动物手术之间用热珠消毒器对器械尖端进行消毒。尽管“仅使用尖端”技术被广泛使用，但对于在引入细菌污染之前同一组经热珠消毒的器械可用于连续手术的次数，仍缺乏相关研究。我们在3种不同条件（无菌、皮毛污染或盲肠污染）下使用“仅使用尖端”技术进行了一系列小鼠手术，并在每轮热珠消毒前后评估需氧细菌的生长情况。在一系列连续手术中，器械尖端被至少一种器械污染的概率呈上升趋势。对于涉及意外污染或皮毛污染的每次手术，热珠消毒后该系列中所有手术器械尖端均无菌的概率下降4%；对于所有手术类型（包括进入胃肠道）的污染手术，每次手术该概率下降11.5%。根据我们的结果，热珠消毒对于与严重污染相关的手术是不够的。在我们的实验条件下，并假设连续手术之间的结果相互独立，对于与轻微或意外污染相关的手术，最多可连续进行5次手术，且所有手术的所有器械尖端均无菌的概率高于80%。应进行逐案风险评估，以制定机构指南，确定使用“仅使用尖端”技术并在手术之间对同一组手术器械进行热珠消毒时可连续进行的最大手术次数。每次手术后对器械进行完全消毒能最大程度地确保维持无菌状态。
