不可冷凝气体造成灭菌失败的影响因素分析

Analysis of influencing factors of sterilization failure caused by non-condensable gas

目的研究脉动真空压力蒸汽灭菌过程中不可冷凝气体(NCGs)对手术器械灭菌带来的风险,为提高灭菌质量,降低感染提供策略依据。方法在灭菌过程中,灭菌器吸入不同比例的空气,分别为0%、0.14%、0.70%、1.40%四个实验组,通过温度压力检测仪,测试管腔手术器械内和标准测试包的温度变化。同时,记录每次实验中的物理、化学和生物监测的结果。结果引入0.14%的NCGs,平均最低温度(AMT)下降为124.26℃,温度探头在器械管腔中的维持时间下降。引入0.70%NCGs,AMT为103.42℃,器械管腔内温度探头开始达不到设定的灭菌温度,6类过程验证装置(PCD)在三次实验中均不合格,标准测试包中的生物指示剂(BI)开始出现阳性。引入1.40%NCGs,AMT为86.21℃,BI阳性率增加,6类PCD和管腔PCD的结果均不合格。所有测试中,5类指示卡和5类PCD均合格。结论少量的NCGs(0.14%)就有可能导致灭菌失败,管腔型器械失败风险较高。传统的监测方案难以暴露问题,存在局限性。5类指示物对NCGs的监测能力低于BI,作为植入物提前放行的依据,造成风险加大。温度压力检测仪和6类PCD可以较早记录或者发现NCGs造成的影响。

OBJECTIVE To study the risk of non-condensable gases(NCGs) on the sterilization of surgical instruments in pulsating vacuum pressure steam sterilization process, so as to provide strategic basis for improving sterilization quality and reducing infection. METHODS During the sterilization process, the sterilizer inhaled different proportions of air, which were 0%, 0.14%, 0.70% and 1.40%, respectively. Through the temperature and pressure detector, the temperature changes in the lumen surgical instruments and the standard test pack were tested. At the same time, the results of physical, chemical and biological monitoring in each experiment were recorded. RESULTS With the introduction of 0.14% NCGs, the average minimum temperature(AMT) dropped to 124.26 ℃, and the maintenance time of temperature probe in the instrument lumen decreased. When 0.70% NCGs was introduced, the AMT was 103.42 ℃, and the temperature probe in the instrument lumen began to fail to reach the set sterilization temperature. 6 types of process challenge device(PCD) failed in three experiments, and the biological indicator(BI) in the standard test package began to show positive results. When 1.40% NCGs were introduced, the AMT was 86.21 ℃, and the BI positive rate increased. The results of 6 kinds of PCD and lumen PCD were all unqualified. In all tests, type 5 strips and types 5 PCD were qualified. CONCLUSION A small amount of NCGs(0.14%) may lead to sterilization failure, and the failure risk of lumen instruments is high. The traditional monitoring scheme is difficult to expose problems and has limitations. The monitoring ability of 5 type indicators for NCGs was lower than that of BI, which was used as the basis for early release of implants, resulting in increased risk. Temperature and pressure detector and 6 types of PCD can record or detect the effect of NCGs earlier.