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Washer Disinfector Process vs Result

Washer Disinfector Process versus the result

Washer-disinfectors follow strict processes to deliver clean and safe to handle instruments ready for sterilization. Over the years I have been looking into different designs of washer-disinfectors but the process itself was rarely a subject for consideration. Parameters were adjusted within a rigid framework of initial rinse, main wash with chemical, rinse and disinfection stage. And do not get me wrong – I am not simply suggesting to swap them around or use multiples of some but rather to consider the ultimate end goal. It is a paradigm shift but one that allows approaching the core of the problem and then to look at ways to solve it. In the case of washer-disinfectors, the goal is to have clean and safe to handle instruments, ready for sterilization.

To be perfectly clear – I am not suggesting neglecting the current methodology just proposing that there may be more efficient and quicker ways of achieving the goal. Ultimately there is a spectrum of available methods to determine whether the process was successful or not and that is what should be the deciding factor. Perhaps this is time to break the mould and redefine the approach without fear of being crushed by the “elders” of the tribe for abandoning tradition.

Design implications

It is generally agreed that the design of washer-disinfectors should aim to maximise efficiency through reducing cycle time, increasing throughput and providing a flexibility that matches the advancement in surgical instruments technology. The cycle time depends on predefined lengths of cleaning stages as well as additional activities like water filling, preheating and draining. By focusing on the additional activities the cycle time can be significantly reduced but only to a certain extent as going beyond it no longer makes commercial sense. At this point, we reach the maximum efficiency that can be achieved under the current mindset. To go further we need a quantum leap.

Now imagine that additional activities become background processes in the cycle. The cleaning process does not stop to fill, preheat and drain. Water is exchanged simultaneously and applied at the desired temperature. It is not difficult to assess the potential time-saving in this case. I can imagine critics saying that it will never work for a plethora of reasons but I am confident it can be done! What is required is just an ‘out of the box’ approach and an open mind.


What I have discussed above is just one concept. What needs to be taken into consideration is that this proposal will take some research and development time to deliver a final product. What is important however is that I believe we should focus more intensively on the outcome rather than the process itself. Advancement in surgical instrument technology and equipment is significant at the moment and results in a gradual increase in their complexity. Decontamination sciences and technology should follow these developments closely. I believe that we are entering an era of tailored solutions and flexible intelligent machines that will be adapting to changing conditions. Machines, processes and chemistry will have to become more and more complex to meet the coming challenges not only from the technological but also microbiological perspective.

this article is by Pawel de Sternberg Stojalowski ( for publication on our blog, we hope you find it interesting.

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Daniel Coole has been involved in the surgical instruments and the medical device industry for the past 17 years and is the Managing Director of innovative surgical instrument manufacturer, Surgical Holdings. Daniel is also the Vice Chairman of the Association for British Healthcare Industries Surgical Instrument Group.

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