Takatsugu Itabashi

Residual Disinfector on Endoscope after Disinfection.

In 1993 we described a newly designed disinfector for flexible laryngeal fiberoptic endoscopes which used glutaral solution and running water. The endoscope was first dipped in glutaral solution and then washed thoroughly in the washer with running water. Because of its coagulative effect on protein, glutaral solution should not be applied directly to the mucosa.In this study we tried to investigate if the glutaral solution was detectable on the surface of the endoscopes after washing. The detection of the glutaral solution was carried out using a color comparaison method with fuchsin.In all 60 trials of testing after 3 minutes or less of washing by the washer, no glutaral solution was detected on the surface of the endoscopes which had been dipped in the solution. However, in tests of old endoscopes with rough surfaces caused by extream usage, over 2 ppm of glutaral solution was detectable after 2 minutes of washing.In conclusion, when the disinfector which we had designed was applied for the disinfection of endoscopes, less than 2 ppm of glutaral solution (which is thought to be safe for human skin) remained on the surface after 3 minutes of washing, as long as the endoscope had not been damaged by excessive use.

Bacteriological Study on a New Washer with Running Water for Fiberoptic Endoscopes.

Sterilization of the flexible laryngeal fiberscope was tested with a newly designed washer which uses running water. Its efficacy was studied in 102 patients undergoing endoscopic examinations.The main part of the washer was a cloro-vinyl pipe 16 mm in diameter, into which the fiberscope was inserted, and fresh water was kept flowing for 3 minutes. Statistically, 1.65 strains of bacteria were detected at the tip of the endoscopes immediately after endoscopic examinations.The incidence of the cases which all strains of bacteria detected before washing were disappeared was 83.3%, and the non effective cases by washing were 9.8%. The cases were 24.5% which a few new strains of bacteria never detected pre-washing were appeared postwashing. These strains of bacteria detected after washing were small in quantity and revealed pathologically low grade. The tips of the nasal endoscopes used in patients with epistaxis all had negative occult blood tests after washing for 5 minutes. The use of the washer was considered to be clinicaly effective in the occasion of the continuous endoscopy.