A new quantitative method for determining patient risk for reusable medical device categorization based on using and interpreting Kremer's cleaning classification system

Background: The cleaning of reusable medical devices involves inherent challenges that can impact on the effectiveness of the cleaning process; consequently, the subsequent safety of patients. Fluid dynamics play a critical role in determining the flow and distribution of cleaning agents where the design of the device can either facilitate or hinder this important process. Complex geometries, narrow channels, or irregular surfaces can impede effective flushing of contaminants leading to incomplete cleaning that creates a greater likelihood for patient contamination risks. Methods: Device features (N = 23) were exposed to the most challenging cleaning conditions to find the point of failure in both fluid dynamics and soil retention. Experimental results obtained from the aforementioned along with associated compound risks were used to assign a risk value. Using the ‘hardest to clean’ device feature approach as the base risk value, the total quantitative risk score was calculated for different reusable medical devices from numerical values obtained from addressing 14 questions focusing on variability in geometry, material use, types of cleaning, and intended patient use. Patient risk values for devices with different features were calculated from using Kremer's cleaning categories based on position within value ranges. Findings: Occurrences less than 18 correspond to minimal risk devices while a total risk score between the values of 18 and 39 are moderate and ≥40 scores corresponds to the maximal category. Conclusion: Application of this quantitative assessment approach will facilitate appropriate mitigation of risk for cleaning reusable medical devices by informing use of targeted effective interventions. Future use of this Kremer cleaning classification will complement and augment disinfection and sterilization modalities.