Test report Endoscope channel pre-cleaning: Pull-Thru versus Traditional brushing

Transcription

1 Page 1 of 16 Process: Test report Endoscope channel pre-cleaning: Pull-Thru versus Traditional brushing Endoscope channel pre-cleaning For Approval Name Function Signature Author: Dave Kok Head CSA / DSMH Deventer Hospital John Stokx René Tillmanns Area Sales manager Minntech BV Account Manager Minntech BV Distribution Name Address Name Address Rev. Description - First release Revision

2 Page 2 of Table of contents 1. Table of contents Objective Framework Introduction References Measuring method Discussion of test results Conclusions Objective Comparing various methods for pre-cleaning the channels of flexible endoscopes. 3. Framework This report has been created through close collaboration between Deventer Hospital as an interested partner in innovative cleaning methods and Minntech BV as the authorized representative of Pull Thru in the Netherlands. The tests were performed at the Central endoscope cleaning department of Deventer Hospital. 4. Introduction (International) guidelines and manufacturers of flexible endoscopes require that endoscope channels be mechanically cleaned before further automatic processing in a cleaning/disinfection device. In Dutch practice, endoscope channels are mechanically cleaned by submerging the endoscope in a soapy solution and then brushing the channels (several times) with a suitable brush (see figure 1). This can be a single-use brush or a reusable brush. The reusable brush is cleaned and disinfected after each use. Fig. 1. Single-use or disposable brush (Olympus) After brushing the channels are flushed and the endoscope is then ready for further automatic processing.

3 Page 3 of 16 Wiping with Pull-Thru is a new method for mechanical channel cleaning. Pull-Thru consists of a plastic cable with three (mini Pull-Thru) or 5 wiper elements (Pull-Thru) attached to it. The mini Pull-Thru is suitable for channels of 1.4 to 2.6mm. The regular Pull-thru is designed for channels of 2.8 to 5mm. See fig. 2. Fig. 2. Pull-Thru 2.8-5mm How Pull-Thru functions Other than when brushing a channel, where the brush is inserted first, the cable passes through the channel first when using Pull-Thru. The wiping element is then pulled through the channel. The individual wiper elements take on the shape of the channel and pull the dirt with them (comparable to a windscreen wiper or the plunger of a syringe). See annex 4. Both cleaning methods were tested and compared at Deventer Hospital.

4 Page 4 of References Documents Number Description Rev. Photo annex: Cleaning and disinfection of flexible endoscopes Cleaning and disinfection of flexible endoscopes with working channel 4 3 Materials Number Olympus BW-20T Olympus BW-201 T Pull-thru ZZ2850 Test InstruSponge 345TIS4mm Description Brushes for mechanical pre-cleaning of endoscope channels; multiple use. Brushes for mechanical pre-cleaning of endoscope channels; single use. Pull-thru channel wiper 2.6-5mm; single use Swabs on flexible wire shaft. Interster no Instruments Inventory number See annex 5 Description INTERSTER Genie System Sure ATP Luminescence Meter Model Deventer Hospital Colonoscopes 6. Measuring method ATP luminescence measurement was used to compare the cleaning results of the methods adopted. A detailed description of this measuring method can be found in Annex 1. Preparation of the endoscopes. In order to make the starting situation the same as much as possible, only colonoscopes were used for the tests and only the biopsy (operating channel) was measured.

5 Page 5 of 16 In accordance with the hospital s procedure, the channels were flushed with sterile water after patient use before the endoscopes were taken to the central cleaning department. After their arrival at the CSA, the scopes were alternatingly cleaned with the brush or with Pull-Thru. See also the form in annex 2. The brushing was first performed with a reusable brush and then with a single-use brush. An ATP swab was taken from every colonoscope before and after mechanical cleaning. Consequently, the ATP value of these swabs was measured. These are the measured values that were compared. 7. Discussion of test results Pull Thru versus reusable brushes. First of all, the ATP values of all endoscopes were measured immediately after receipt (before mechanical cleaning). See Anne 3.1 for detailed results. The analysis of the percentages of ATP removed shows a difference between the two cleaning methods. Furthermore, within the brush cleaning method, there is a clear difference between the results obtained with reusable and single-use brushes: Average ATP removal reusable brushes : -51% Average ATP removal single use brushes : -63% Average ATP removal Pull-Thru : -81% A remarkable finding was that within the cleaning method using reusable brushes, the 2 nd measurement of experiments showed higher values than the 1 st measurement. A possible explanation for this finding is insufficient cleaning (washing and disinfecting together with endoscopes) of the brushes between two uses. 8. Conclusions There is no significant difference in the level of contamination of the endoscopes provided. The endoscopy population is equal. Wiping with Pull-Thru eliminates 18% more ATP (bio material) than brushing with an singleuse brush. Wiping with Pull-thru eliminates ±30% more material than cleaning with reusable brushes.

6 Page 6 of 16 Brushing with single use brushes eliminates 12% more material than brushing with reusable brushes. removed Brush, reusable Brush, single-use Wiper

7 Page 7 of 16 Annex 1. ATP measurement. Adenosine-triphosphate (ATP) is a molecule responsible for the transportation of energy in organisms. Hence, the presence of ATP indicates the presence of biological material. The measurement of ATP is common practice in central sterilization units of hospitals for measuring the efficiency of the cleaning process (removal of biological material). The phenomenon of bioluminescence is best know from the flashes emitted by fireflies. These light flashes are emitted when the enzyme luciferase comes into contact with ATP molecules. These molecules, which are used for energy storage, are present in all living organisms. Of quantity of light produced is directly proportional to the quantity of ATP molecules that are present, and is measured with very sensitive light meters (luminescence meters). The quantity of light measured is usually expressed in Relative Light Units (RLU). Using the ATP bioluminescence test we can measure the quantity of ATP that remains on a cleaned surface. The quantity of ATP is a measure for the inefficiency of the cleaning process. For the test, a fixed amount of luciferine and enzyme are used; these are present in the socalled pens. The ATP that is required for the oxidization of the luciferine is the limiting factor and thus determines the quantity of light emitted. Measuring procedure

8 Annex 2 Measurement form Page 8 of 16

9 Page 9 of 16 Annex Analysis of initial contamination This analysis assesses the initial contamination of the endoscopes. It is of course important that there be no significant difference in initial contamination between the endoscopes used for the test. The following analysis shows that there is no significant difference in initial contamination between the endoscopes. ANOVA Oneway Completely Randomized Design Group 1 Group 2 Group 3 GroupID N Mean 166, , ,45000 Std Dev 197, , ,94814 Median 93, , ,50000 Min 10, , ,00000 Max 975, , ,00000 Combined Group N 106 Mean 183,08490 Std Dev 199,26086 Median 94,50000 Min 0,00000 Max 975,00000 Test the assumption that the populations have equal variances. ANOVA requires this assumption. Null Hypothesis: All variances are equal. Alternative Hypothesis: At least two variances are different. Barletts Chi-Square Test Statistic = 0,0908 P-Value = 0,95561 on 2 df Conclusion: Accept the hypothesis that variances are equal Null Hypothesis: All the means are equal. Alternative Hypothesis: At least two of the means are different. Analysis of Variance Source DF Sums of Squares Mean Square F-value P-Value Treatment , ,67 0,2080 0,81254 Error , ,04 Total ,25

10 Page 10 of 16 Conclusion: Accept hypothesis that means are equal at 0,05 significance level. 3.2 Analysis of cleaning with reusable brushes The analysis of the results of the cleaning process with reusable brushes demonstrates that these brushes remove 51% of the original contamination. Tolerance Interval Estimation Normal Distribution Parameter Estimates (Best Linear Unbiased) Estimate 95% Confidence Interval 51, ,27480 to 63, , ,85446 to 43,64169

11 Page 11 of Analysis of cleaning with single-use brushes The analysis of the results of the cleaning process with single-use brushes demonstrates that these brushes remove 63% of the original contamination Tolerance Interval Estimation Normal Distribution Parameter Estimates (Best Linear Unbiased) Estimate 95% Confidence Interval 62, ,95205 to 70, , ,80457 to 31,04369

12 Page 12 of Analysis of cleaning with Pull-Thru wiper The analysis of the results of the cleaning process with Pull-Thru wipers demonstrates that these brushes remove 81% of the original contamination. Estimation Normal Distribution Tolerance Interval Parameter Estimates (Best Linear Unbiased) Estimate 95% Confidence Interval 81, ,92073 to 87, , ,13086 to 24,01126

13 Page 13 of 16 Annex 4 Use of Pull Thru Insertion: cable first. Lamellae take the form of the channel diameter. The dirt is pulled out of the channel. Pull Thru sweeps the blood out of the channel in one pass.

14 Page 14 of 16 Annex 5 Measurement data Reusable brush

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16 Page 16 of 16 Single use Date Time Colonoscope no: Pre-swab Post-swab % soil removed Clean with ,26316 single-use brush ,73134 single-use brush ,33333 single-use brush single-use brush ,45455 single-use brush ,47644 single-use brush ,45455 single-use brush ,17949 single-use brush ,66667 single-use brush ,85714 single-use brush ,43243 single-use brush ,6087 single-use brush ,00195 single-use brush ,45504 single-use brush ,29825 single-use brush ,57895 single-use brush ,8209 single-use brush ,80645 single-use brush ,79245 single-use brush ,89474 single-use brush ,35294 single-use brush ,27273 single-use brush ,54955 single-use brush ,43137 single-use brush ,85859 single-use brush single-use brush ,61417 single-use brush ,43396 single-use brush single-use brush ,5 single-use brush ,15686 single-use brush ,48148 single-use brush single-use brush , single-use brush ,57143 single-use brush ,08434 single-use brush ,1195 single-use brush ,46575 single-use brush ,08846 single-use brush ,53865 single-use brush