EVALUATION REPORT DISPOCLEAN ENDOSCOPE CLEANING BLADE ALKAPHARM UK Ltd June 2008 HOSPITAL INFECTION RESEARCH LABORATORY CITY HOSPITAL DUDLEY ROAD BIRMINGHAM B18 7QH
SUPPLIER/MANUFACTURER Alkapharm UK Ltd Pillaton Hall Pillaton Penkridge Stafford ST19 5RZ UK OBJECTIVE A comparison between the efficacies of the DispoClean endoscope cleaning blade and an endoscope brush will be made by assessing the removal of artificial soils from the lumina of a surrogate device. The brushes used were Olympus single use channel cleaning brushes. The effect of Alkazyme liquid concentrate enzymatic instrument cleaner and a neutral detergent upon cleaning was also investigated. DESCRIPTION The DispoClean endoscope cleaning blade is a device designed to clean the long narrow lumina of accessible channels of flexible endoscopes. Currently, the predominant practice is to clean with single use brushes. Alkazyme liquid concentrate enzymatic instrument cleaner is the first dedicated mono enzymatic cleaning-disinfectant agent for all immersable and heat-labile surgical and medical instruments. Its combined enzymatic/detergent action digests and removes proteins from instruments, reducing their bioburden prior to sterilization. TECHNICAL DETAILS DispoClean Green: For use on gastroscopes and all 2.8-3.2mm channel endoscopes DispoClean Yellow: For use on colonoscopes, duodenoscopes and all 3.2-4.2mm channel endoscopes Olympus single use channel cleaning brush: For use on all 2.0-4.2mm channel endoscopes 2 of 9
Tests were carried out with the following detergents: Alkazyme liquid concentrate enzymatic instrument cleaner (lot no: 5841, use by 03-2010). Hospec general purpose neutral liquid detergent. METHOD The lumina of surrogate devices were soiled using two artificial test soils. The test soils used were Edinburgh soil and Respiratory soil, as described in HTM 2030 Washer Disinfectors: Validation and Verification section 19.22. The constituents of Edinburgh soil are egg yolk, defibrinated sheep/horse blood, and hog mucin. The constituents of Respiratory soil are water, glycerol, horse serum, hog mucin, plain flour, safranine and wallpaper paste. 5 ml of artificial test soil was passed through the lumen of each surrogate device; excess soil was subsequently expelled by passing 2 x 20ml of air along each device. The soiled devices were allowed to dry at room temperature for 30 minutes. After soiling, the lumina of the surrogate devices were cleaned with either a DispoClean or a channel cleaning brush, using either Alkazyme liquid concentrate enzymatic instrument cleaner or Hospec general purpose neutral liquid detergent. When cleaning with the DispoClean blade, one pass was made along the lumen of each device; when the Olympus single use channel cleaning brush was being used, at least three, or as many passes as necessary until the brush tip was clean upon exiting the distil end of the surrogate device, were used whichever was the greater. After cleaning, the lumina were visually inspected for the presence of soil. Each surrogate device was then flushed with 20ml sterile water and 2 x 20ml air. This reflects what happens in clinical practice. After flushing, the lumina were rinsed with 3ml sterile water; this water was collected and analysed for the presence of residual protein using the Ninhydrin test. The test was repeated 5 times for each procedure. 3 of 9
RESULTS The results are displayed in tables 1-4. Key: - = no soiling +/- = scant soiling + = light soiling ++ = medium soiling +++ = heavy soiling VI = visual inspection N = ninhydrin Both DispoClean and the Olympus single use channel cleaning brush removed all detectable protein from the surrogate devices, as assessed by the Ninhydrin test. Upon visual inspection, scant soiling was often detectable in the surrogate devices challenged with Edinburgh soil (19 out of 20 lumina). In contrast, those lumina contaminated with Respiratory soil rarely displayed visible soil post cleaning (18 out of 20 surrogate devices were visibly clean). All visible soil remnants were removed by the flushing procedure. No surrogate device tested positive for residual protein (0 out of 40 lumina). When using the DispoClean, there was no discernable difference between the results obtained with Alkazyme and neutral detergent. Used in conjunction with the endoscope cleaning brush, neutral detergent was marginally less effective than Alkazyme in removing visible soiling from lumina challenged with Edinburgh soil: a total of 19 passes was required over the 5 tests, compared with 16 for Alkazyme. 4 of 9
Table 1 DispoClean. 1% v / v Alkazyme Edinburgh Soil Respiratory Soil Passes VI N Passes VI N 1 1 +/- - 1 - - 2 1 +/- - 1 - - 3 1 +/- - 1 - - 4 1 +/- - 1 - - 5 1 +/- - 1 - - 5 of 9
Table 2 DispoClean. 0.1% v / v Hospec Edinburgh Soil Respiratory Soil Cycle Passes VI N Passes VI N 1 1 +/- - 1 - - 2 1 +/- - 1 - - 3 1 +/- - 1 - - 4 1 +/- - 1 - - 5 1 +/- - 1 - - 6 of 9
Table 3 Channel cleaning brush. 1% v / v Alkazyme Edinburgh Soil Respiratory Soil Cycle Passes VI N Passes VI N 1 4 - - 3 +/- - 2 3 +/- - 3 - - 3 3 +/- - 3 +/- - 4 3 +/- - 3 - - 5 3 +/- - 3 - - 7 of 9
Table 4 Channel cleaning brush. 0.1% v / v Hospec Edinburgh Soil Respiratory Soil Cycle Passes VI N Passes VI N 1 5 +/- - 3 - - 2 4 +/- - 3 - - 3 4 +/- - 3 - - 4 3 +/- - 3 - - 5 3 +/- - 3 - - 8 of 9
CONCLUSION Manual cleaning of all endoscope channels is recommended prior to processing in an automated endoscope reprocessor. Single use cleaning devices are recommended. The DispoClean endoscope cleaning blade is designed to clean the long narrow lumina of accessible channels of flexible endoscopes, as an alternative to a brush. This study was designed to compare the efficacy of DispoClean with the Olympus single use channel cleaning brush. Both DispoClean and the Olympus brush were highly effective at removing artificial test soils from the lumina of surrogate devices: no more than scant visible soil remnants were detected post-clean, and no residual protein was detected by the Ninhydrin test. However, fewer passes of the DispoClean blade were required to remove the artificial soil (one, compared with at least three for a brush). The DispoClean endoscope cleaning blade offers a quick and effective approach to manually cleaning endoscope channels prior to automated reprocessing. Testing by the Hospital Infection Research Laboratory does not imply approval or endorsement... MAC Wilkinson Biomedical Statistician.. CR Bradley Laboratory Manager.. Dr A Fraise Director 9 of 9