Central Service - Issue 3/2013
- What's New in Standardisation: Pressure
- Medical device reprocessing on the agenda at the 10th Ulm Hospital Infection Symposium
- Reprocessing in Europe's capital city of culture. 35th French National Sterilization Days, Marseille, 10 - 11 April 2013
- Reprocessing, value preservation and reuse of medical instruments. 6th Medical Instruments Colloquium of the wfk - Cleaning Technology Institute e. V., 11 April 2013, Düsseldorf
H. Biering, U. Beilenhoff, M.Heintz:
Investigation of the cleaning efficacy of washer-disinfectors for thermolabile endoscopes - Multicentre trial on using a tube model with protein detection
Following the publication of the Guideline for Validation of Automated Cleaning and Disinfection Processes for Reprocessing Thermolabile Endoscopes (currently not available in English), a multicentre trial was conducted on behalf of the German Society of Endoscopy Nurses and Assistants (DEGEA) in which, pursuant to Annex 8 of the guideline, test pieces in the form of a tube model were investigated with protein detection. This trial assessed testing and evaluation of the cleaning efficacy at the time of validation as well as the specifications for the acceptance criteria in 17 endoscopy units in terms of their suitability under practical conditions. The cleaning processes were tested in ten washer-disinfector models using alternating combinations of seven different detergents. The results of the multicentre trial demonstrated that the majority of the processes tested met both acceptance criteria, i.e. optical cleanliness and residual protein amount in the test pieces. However, faulty connections, one technical defect as well as inadequate cleaning efficacy of washer-disinfector processes were also detected. In the multicentre trial the test pieces and combination of acceptance criteria proved to be suitable for verifying the cleaning efficacy during performance qualification at the time of validation.
multicentre trial cleaning efficacy washer-disinfectors thermolabile endoscopes test pieces protein determination OPA method
M. Wehrl, W. Michels:
A method for testing the cleaning of MIS robotic instruments
The working group DaVinci («AG DaVinci») was founded in order to establish a unified and reproducible test method to quantify the cleaning effect of robotic instruments that had been contaminated by actual use and then reprocessed. Since the instruments have several unique features in terms of their design and the materials used, special elution methods are needed for demonstrable recovery of the residual soils. The group developed a detailed protocol for the method to determine the residual protein content on the instrument type Maryland Bipolar Forceps (MBF; manufacturer: Intuitive Surgical Inc., CA, USA), which is representative for robotic instruments. To establish the method, the participants of the group conducted several round robin tests aimed at, inter alia, determining the recovery rates using different methods of protein quantification. The results of these round robin tests will be published in a subsequent paper.
minimally invasive surgery robotic instruments DaVinci cleaning residual protein
W. Michels; K. Roth; R. Eibl:
Assessment of cleaning efficacy based on the protein-surface relationship
Residual soils persisting after manual or automated cleaning can jeopardize the disinfection and sterilization results and pose a risk of immunological reactions, if transmitted to the patient when the instruments are reused. In any case, the adverse effects on the post-cleaning reprocessing steps will depend on the thickness of the layer of residual soils and on how well pathogens are embedded in such soils and, thus, protected against the inactivating agent. The amount of residual protein than can be transmitted when the instrument is reused will also depend on the surface area coming into contact with the patient and on the protein amount that can be thus transmitted. This means that the surface-related amount of contamination is of decisive importance. This can be explained by stating, by way of analogy, that no absolute pollutant quantity can be defined for an ocean, lake or pond, rather this can only be expressed in terms of concentration in quantity per litre. To specify acceptance criteria for performance qualification using the same principle, the values that can be achieved in practice when using current state of the art methods were explored by consulting validation reports. There is no other principle that can be invoked for specification of acceptance criteria for cleaning.
Validation reports compiled in 2011 and 2012 were evaluated. Since the cleaning results in practice are subjected to a constant optimization imperative, but reproducible compliance must also be feasible and demonstrable, an acceptance value of = 3 µg per cm2 was deemed reasonable in the light of the results obtained.
cleaning surgical instruments residual protein performance qualification acceptance criteria
Low-temperature sterilization, Evaluating the cleaning performance of detergents
Recommendations by the «Quality Task Group»: Sterile barrier and packaging systems