Lumen claims of the STERRAD 100NX sterilizer: Testing performance limits when processing equipment containing long, narrow lumens

BackgroundAccording to manufacturers information, the STERRAD 100NX sterilizer—a low temperature H2O2 gas plasma sterilizer—can adequately process single channel stainless steel lumens with an inside diameter of 0.7 mm or larger and a maximum length of 500 mm using standard cycle sterilizing conditions. The aim of this study was to qualify the performance of this H2O2 gas plasma sterilizer under different experimental settings representing worst case conditions.MethodsInoculated carriers were placed at the midpoint position of specified lumens and then submitted to flex scope sterilizing conditions. To simulate insufficient cleaning or crystalline residues, we added organic and inorganic challenges to our inoculated carriers.ResultsFor experiments done with unchallenged carriers, quantitative analysis reached a log10 reduction rate of ≥5.71, whereas qualitative results showed no growth in 24 out of 30 biologic indicators tested using flex scope half cycle conditions. Any additional kind of challenge significantly impaired the sterilization outcome.ConclusionThe findings of our current study emphasize the importance of a thorough validated cleaning of medical devices as well as timing for cleaning and decontamination before being exposed to the H2O2 sterilization process and, furthermore, the need for strict adherence to manufacturer’s recommendations.