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s Ummary
comParatiVe anaLysis oF PasteUrization anD thermaL DisinFection in a Washer- DisinFector: anesthesia anD resPiratory DeVices
Introduction
In Québec, pasteurization is the reference method for high-level thermal disinfection of anesthesia and respiratory devices. Thermal disinfection by water spray in a washer-disinfector is a method that is hardly used, however, and its effectiveness is often questioned.
Anesthesia and respiratory devices
Anesthesia and respiratory devices are classified as semi-critical devices: equipment that comes into contact with mucous membranes or non-intact skin without penetrating it. Studies show that these devices are contaminated by micro-organisms, primarily bacteria from the mouth and respiratory tract. Reusable anesthesia and respiratory devices must be reprocessed by high-level disinfection or sterilization. Reprocessing can be either chemical or thermal.
Thermal disinfection methods include pasteurization and disinfection in a washer- disinfector. The first method involves immersing the equipment in water heated to at least 71˚C for 30 minutes. The second method involves exposing devices to water spray based on a time-temperature combination set to achieve a safe reprocessing level (from 80˚C for ten minutes to 90˚C for one minute).
Objective and method
This technical brief aims to answer two assessment questions: (1) What is the effectiveness of the thermal-disinfection cycle in a washer-disinfector compared with that of pasteurization for
reprocessing anesthesia and respiratory devices?
(2) What are the economic implications of using these two procedures?
A MEDLINE search covering the period from January 1980 to April 2008 and updated in May 2009 identified relevant studies on this topic.
Standards, recommended practices and guidelines dealing with the reprocessing or disinfection of anesthesia and respiratory devices were also consulted.
Results
The Canadian standard Z314.8-08 recommends using pasteurization to reprocess anesthesia and respiratory devices. This standard also recognizes disinfection in a washer-disinfector as an
alternative procedure for reprocessing these devices but does not provide any requirements as to its performance parameters.
Disinfection in a washer-disinfector is used and regulated primarily in Europe, where its effectiveness has been proven. The international standard ISO 15883 (Parts 1 and 2) requires that washer-disinfectors for reprocessing anesthesia and respiratory devices achieve a minimum A0 value of 600 seconds, that is, thermal disinfection at 90˚C for one minute, or the equivalent. This standard was endorsed by the Canadian Standards Association (CSA) and published as CSA-Z15883.
Studies show that pasteurization and thermal disinfection in a washer-disinfector are both effective for disinfecting anesthesia and respiratory devices. These procedures destroy vegetative bacteria, mycobacteria, fungi and viruses but not spores.
Economic analysis shows that annual operating costs for a washer-disinfector are significantly equivalent to those of a pasteurizer ($10,657 compared with $9,425). However, the multi- purpose nature of a washer-disinfector yields a non-negligible benefit both financially and organizationally.
Extract from the technical note prepared for AETMIS by Christine Lobè
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Discussion
The studies analyzed were performed in
experimental conditions. Some of them date back several years and do not necessarily reflect current technological advances. The parameters tested in these studies nevertheless met the requirements set out in CSA-Z314.8-08 for pasteurization and also those in ISO 15883 for disinfection in a washer-disinfector. Moreover, the CSA’s recent endorsement of the international standard responds to Québec practitioners’ concerns over the use of washer-disinfectors for the thermal disinfection of anesthesia and respiratory devices.
Conclusion
In light of the scientific literature, AETMIS finds that thermal disinfection in a washer-disinfector that complies with the requirements of ISO 15883 or CSA-Z15883 and that fits the description provided in CSA-Z314.8-08 is equivalent to conventional pasteurization and is effective for reprocessing anesthesia and respiratory devices.
comparative analysis of Pasteurization and thermal Disinfection in a Washer-Disinfector: anesthesia and respiratory Devices
