Observational study of enzyme in instrument cleaning for sterile reprocessing and factors impacting enzyme activity

摘要

Objective To evaluate the application of enzyme in instrument cleaning for hospital sterile reprocessing and different factors that impact the enzyme activity.Methods Standard soil objects for instrument cleaning quality evaluation,as testing coupons,were identified and used to evaluate different cleaning processes designed with varied conditions.Between testing groups using enzymatic detergent versus non-enzymatic detergent,the amount of residual protein on the testing coupons were quantified and compared at different soaking time(10min,20min,30min,45min and 60min).Then,within the enzymatic detergent group,different testing conditions were further explored by adjusting factors,in⁃cluding the soaking temperature(25°C,30°C and 45°C),use solution pH(7.0,8.0),and enzyme dosing(1/80,1/40,1/20,3/40,1/10 and 3/20 in v/v).Then,through an observational comparative study for each testing condition,the time needed to achieve a complete soil removal through visual inspection of the testing coupons was documented for analyses.Results In the test of enzymatic detergent versus non-enzymatic detergent,the non-enzymatic group did not show an obvious decline in the residual protein amount(1069μg at 10 min vs.1042μg at 60 min),whereas the enzymatic group showed significant decrease in residual protein quantity(947μg at 10 min vs.620μg at 60 min).Meanwhile,the amounts of the residual protein at different time points in the enzyme group(947μg at 10 min,864μg at 20 min,812μg at 30 min,691μg at 45 min,and 620μg at 60 min)were consistently lower than those at the same time schedule in the non-enzyme group(1069μg at 10 min,1069μg at 20 min,1067μg at 30 min,1059μg at 45 min,and 1042μg at 60 min).Furthermore,within the enzymatic group,the soaking temperature,use solution pH and enzyme dosing factors all appear to impact the enzyme activity and significantly contribute to the cleaning outcomes.Specifi⁃cally,the higher soaking temperature,higher use solution pH and higher enzyme dosing showed 58.4%,20.0%and 34.4%time reduction to completely remove the soil on the testing coupons,respectively.Conclusion Enzyme seems to play a significant role in the instrument cleaning process for hospital sterile reprocessing.The soaking temperature,cleaning use solution pH,and enzyme dosing all appear to be critical factors impacting the enzyme activity and thus the overall cleaning outcomes.In practice,cleaning process verification should be considered to ensure the optimal use conditions for enzyme cleaning performance are well-understood and consistently achieved at the facility level.