Test Soil and Material Affinity for Reusable Device Cleaning Validations.

While selecting the test variables for a cleaning validation for reusable medical devices, the manufacturer must provide a simulative and clinically representative challenge for the device. An appropriate challenge must be identified with care so as not to overchallenge the cleaning process by selecting the worst case for every variable, thus leading to an impossible validation or unrealistic processing requirements. To appropriately select the testing variables, an understanding of the challenge to the cleaning process is important.

Improving Protein Assay Methods to More Accurately Assess Medical Device Cleanliness.

Protein assays commonly used to evaluate reusable device cleanliness do not always accurately measure the low concentrations of protein that are expected on reusable medical devices after processing. Methods often are adapted to provide an estimation of protein concentration; however, sensitivity issues in the portion of standard curves at the acceptance criteria of 6.4 μg/cm protein have been reported.

Chemical Changes Over Time Associated with Protein Drying.

Upon drying, physical changes of the characteristics of proteins are observed by coagulation, but the nature and chronology of these changes have not been well studied. Coagulation changes the structure of protein from liquid to a solid or a thicker liquid by heat, mechanical action, or acids. Changes may have implications regarding the cleanability of reusable medical devices; therefore, an understanding of the chemical phenomena associated with drying of proteins is essential to ensuring adequate cleaning and mitigation of retained surgical soils.

Connecting Across Competencies: Leveraging Best Practices for Processing.

The AAMI working group ST/WG 93 is finalizing a standard (AAMI ST98) for the cleaning validation of reusable medical devices based on guidance from the technical information report AAMI TIR30:2011/(R)2016. A number of analytical best practices are being considered for this new standard. Test method suitability for processing cleaning validations historically has been established using one positive control and performing an extraction efficiency.