Abstract
In the disinfecting process of endoscopes with electrolyzed acid water and glutaraldehyde, we have found the deteriorations with rough texture on the outer coated surface of endoscopes after about 2,000 uses. We looked into the cause, analyzing the rugged surface, as follows. (1) The surface was observed by a digital microscope in 50 magnifications, and compared with the surface of new endoscopes. (2) The surface was analyzed and compared by a Fourier transform infrared spectrophotometer. (3) The rugged surfaces were cut off from the endoscopes in question to analyze the deteriorated material, and observed by a scanning electron microscope in 50,500 and 5,000 magnifications. (4) In use of sodium hypochlorite we found suitable to dissolve the deteriorated material, we transformed the dissolved material to powder through neutralization, salting out and freeze-drying. We made the analysis in the powder form.
Conclusions : (1) The material dissolved in sodium hypochlorite was quantitated to 16 amino acids. We inferred that the deteriorated surface in hard accumulated layers was a substance polymerized and cross-linked of small amounts of protein, which was left after the endoscopes were washed, with glutaraldehyde. It was not known how electrolyzed acid water affected this. (2) For removal of this hard rugged substance, we found sodium hypochlorite useful and possible to recover the glossy smooth surface. We concluded that endoscopes should be thoroughly cleaned with enzymatic or neutral detergents before disinfecting process, without using glutaraldehyde.
