ATPを指標とした医療現場における洗浄プロセス評価

Abstract

We have reported the qualification result of Adenosine Tri-phosphate (ATP) extraction as an alternative cleaning process assessment method described in Guideline for Sterilization Assurance in Clinical Setting published by Japanese Society of Medical Instrumentation (JSMI) in 2010 at JSMI Annual Conference 2012. This study result indicated the possibility of that ATP extraction method is practical in clinical setting and can be an alternate to protein mass measurement because of the evaluation result regarding the correlation study result between ATP and protein measurements. In this article, additional study result of cleaning process assessment is reported using clinically-used surgical instruments and artificial soil devices at clinical site. ATP extraction and conventional ATP swabbing as well as protein extraction was performed after two different cleaning processes to evaluate the effectiveness of these cleaning processes for determining which cleaning process to take. It is observed that ATP swabbing is not appropriate for surgical instrument having such narrow lumen and/or space where swab cannot access to, because high ATP value was detected by extraction method from a surgical instrument after sampling with swab for ATP measurement. ATP measurement result from standardized artificial soil devices after one cleaning process was from 66 to 478 relative light unit (RLU) while ATP measurement result after another cleaning process was from 30 to 73 RLU (p value = 0.025). However, such statistical analysis was not achieved for protein measurement as detected protein level was under limitation for all protein measurements. ATP extract method is practical cleaning process assessment method at clinical setting, and this method has quantitative capability as well as excellent sensitivity compared to protein measurement method. In addition to these advantages, this extraction method can be applied to more devices which have physically-complex design and lumen devices compared to conventional swabbing method.