What is the efficiency of using of Electrolyzed Acidic Water (EAW) in disinfecting of flexible endoscopes? Please compare between the using of EAW, Glutaldehide and peracetic acid in the following points

1. Running cost
2. Endoscope damage
3. Biofilm composition
4. Toxicity
5. Skin irritation

Using of EAW is very famous in Japan and there are many studies and reports done there, but there is no studies from Europe or the states.

Best Regards,

Sherif ELsonbaty
Biomedical Engineer

Dear,

this is a very difficult question. Everything depends on the pH of the solution. If this is too low, it will damage the flexible endoscope (external tube will become sticky). If it is too high, there is a chance that some strains of Mycobacteria will not be eliminated so that bronchoscopes might not be disinfected correctly. The only way to confirm material compatibility is to do physical tests with different type of endoscopes and for at least 1500-2000 cycles. Only then can material compatibility be assured. For Europe comes on top that these kind of machines will not be in line with the EU guidelines which will be published probably next year. In other words, these machines do not perform a leakage test on the endoscope, there is no possiblity to clean it and no possbility of drying. Only the disinfection phase is carried out in this kind of machines.

Kind regards
Dr Ives Verheyleweghen
Omnilabo
Belgium

Dear Sirs,

I would like to make some comments and clarifications on this issue:

• pH has nothing to do with disinfection power and also with endoscope damage. Endoscope damage depends on chlorine content of EAW.
• pH has nothing to do with with Mycobacterium killing power.
• I agree that the only way to confirm material compatibility is to perform physical tests with endoscopes.
• there is at least one EAW system that does perform a leakage test on endoscopes
• there is at least one EAW system able to blow out moisture from the endoscope channels by air-blowing; the surface of the scope can be dried by wipping with alcohol. At the end of the daily operations, alcohol flush of the channels is recommended by endoscope manufacturers.
• the same mentioned system has a prewashing/rinsing process (selectable from 1 to 99 minutes) by tap water circulation; this process can remove from endoscopes foreign matters such as residual detergent, blood, etc...
• the same mentioned system has 3 steps: pre-washing to remove foreign matters from endoscopes, disinfection, and final rinsing to eliminate electrolyzed acid water.
• there are many different kind of electrolyzed acid water: strong acid water (low pH = 2.7) and weak acid water (pH = 5.5 - 7). Weak acid water has chlorine content as hypoclorous acid. At pH=5,5, chlorine content is around 200-250 ppm. This electrolyzed acid water may damage endoscopes because of high chlorine content. Although pH is 5.5, it has strong tubercolocidal efficacy.

As regards comparison with other disinfectants:

Best regards,
Monica Cimbro MD
CBC (EUROPE) LTD.
Italy