asepticaNovember 2014 edition | www.aseptica.com

Journal for Hygiene in Hospitals and Medical Practice

Bioluminescence Can ATP measurements provide information about cleaning quality?

6 €

Evaluation of the ATP bioluminescence

method as a test for residual soiling on

cleaned medical devices

Criteria needed to choose a closed

transport trolley system for an optimal

reprocessing flow cycle

Innovative monitoring of sterilisation using

the new EBI 16 Bowie and Dick Test Data

Logger

Reprocessing Kirschner wires – problems

and their solutions

Content Water hygiene and the automatic

reprocessing of endoscopes

Reprocessing recommendations –

comparing AAMI standards with the

'Red Book'

Testing cleaning of problematic and

complex instruments – significance of

manual pre-cleaning

www.aseptica.com

Create pouches easily yourself

Imprint

2 November 2014 edition | Content / Evaluation of ATP / bioluminescence method

The detection of ATP (adenosine triphos-phate) by recording its bioluminescence is often referred to as a test of cleanliness of medical devices after automatic repro-cessing.

No clear correlation of the ATP method could be determined in a comparative evaluation of microbio-logical monitoring connected with the reprocessing of fl exible endoscopes (1, 2). A correlation with non-microbiological contamination is only conjecture. With regard to the reprocessing of surgical instru-

ments it was reported that for cleaned instruments there was a great variation of recorded values. Instruments with a lot of fi brin residues had quite low measurements, whereas instruments that had been handled manually had a quite high value. But there was no correlation with protein volume (3). A student research project investigated the correlation of the results of pro-tein volume to ATP measurements

Evaluation of the ATP bioluminescence method as a test for residual soiling on cleaned medical devices

Dr. Winfried Michels,

c/o Miele Professional

Carl-Miele-Str. 29

33332 Gütersloh

Germany

E-Mail: winfried.michels@miele.de

| Author

for Crile clamps soiled with a defi ned amount of blood, after they had been automatically reprocessed. For both methods sampling was carried out by swab-bing. A correlation coeffi cient of 0.352 was calculated, which is completely inadequate (4). Our own tests also showed that the method is very non-specifi c (5).

Even though these sort of results are widely publi-cised, the method is still being used because this test for assessing the success of cleaning of medical prod-ucts is so simple. People just take the measurements and ask no questions (6). To reach a more profound evaluation, there must be a detailed investigation of where ATP is to be found and what actually happens to ATP on the journey from medical devices soiled by actual use, to waiting for reprocessing, as well as what happens during reprocessing itself.

ATP and its measurement

ATP is the universal energy carrier in every living cell. It is formed in mitochondria from monophos-phate (AMP) and pyrophosphate. Wherever chemical,

W. Michels

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November 2014 edition | Evaluation of ATP / bioluminescence method 3

osmotic and mechanical work is done, ATP delivers the energy by splitting off the pyrophosphate. Thus there is a continual cycle. If the reaction turnover of an adult is added up for a whole day, umpteen kilos result. Cells such as red blood cells (erythrocytes), thrombocytes and also epithelial cells are continually giving up limited amounts of ATP into blood plasma. Endothelial cells also give it up into mucus.

The free ATP reacts with the so-called Firefl y reagent (Luciferin/Luciferase complex) where energy is re-leased in the form of light. The light intensity here relates to the amount of reacted ATP. It can be mea-sured with a luminometer as a relative light unit (RLU). The recorded values are dependent on temperature and especially on pH value. These factors alone can cause enormous fl uctuations in the recorded values.

Blood and ATP content

The lion’s share of ATP in blood is found in erythro-cytes, where cytosol concentration is measured in mil-limoles. Plasma ATP concentration however, is mea-sured in micromoles. But using the bioluminescence method to determine ATP concentration, ATP bound to albumin cannot be detected (7). It is known that for bottled blood the ATP content continually decreases as store time increases (8). Bleeding activates clotting, which sets off increased ATP release from thrombo-cytes as well as erythrocytes. ATP release is also in-creased by haemolysis. So-called nucleotidases, specifi c enzymes found in plasma, rapidly catabolise released ATP (9). Therefore for surgical instruments soiled with blood, we can presume that an unknown -but signifi -cant- proportion of the ATP is already broken down by the time the instruments arrive for reprocessing.

The infl uence of reprocessing on ATP content

Cleaning certainly exposes any still intact blood cells to unphysiological conditions (tap or fully-demineralised water, detergent solution etc.). During cleaning at the latest, blood cells are extensively destroyed because of raised temperatures. How much of the original ATP will still be present and available to be detected?

ATP is a very small molecule with a molecular weight of 507.2. This is very slight in comparison to haemo-globin or albumin, with their molecular weights of

over 60,000. ATP is also very water soluble and is to a large extent extract-ed and rinsed away dur-ing reprocessing. We are aware of this ourselves from experience with haemoglobin, which is extracted from the blood residues and then leaves a white fi brin coating. If we subject the instru-ments to the ATP test before the thermal disinfection stage, then we certainly include pathogens in the rinse water. Any residual soil can falsify the recorded re-sults in both directions, because haem and denatured protein can absorb light or produce secondary fl uo-rescence (10).

Because of all these infl uences it is no surprise that when using the ATP test not even a rough correlation to soil or residual soil can be seen. But the question remains: because of its limited stability (11) just how well does ATP stands up to physical and chemical conditions? Or is ATP already broken down in signifi -cant quantities by cleaning conditions at 55°C or dur-ing thermal disinfection at 90°C? This was investigat-ed using the simple test apparatus of the DIN ad hoc group (12) as well as with thin layer chromatography.

Testing the infl uence on ATP of process conditions within the WD

To test the infl uence of cleaning and thermal disinfec-tion process conditions on ATP and its possible hydro-lysis to ADP (Adenosine diphosphate) and/or AMP (Adenosine monophosphate), two sets of 10ml of 40 μmolar ATP solution was heated with the modifi ed test design, one to 90°C and left for 5 minutes and the other heated to 55°C. 0.5% neodisher Mediclean Forte (from Dr. Weigert, Hamburg) was then added in the latter case and left to act for 15 minutes. The solutions were each cooled down on ice after the action time. 5 μl (0.02 μmol) of ATP, ADP and AMP solutions (pure substances from Sigma, Taufkirchen) were deposited as spots on the start-line of thin layer plastic sheet (DC-polyester sheet Polygram CEL 300 PEI/UV, Ma-cherey-Nagel, Düren) and the solutions treated in the test design were applied in the same way. The sheet was

Figure 1:

Bioluminescence is a

biochemical reaction.

The enzyme luciferase

splits the protein luciferin

in the presence of oxygen

and ATP. Energy is released

in the form of light.

Luciferase

Luciferin+O

2

Oxyluciferin+ Light

+ ATP

placed in the DC chromatography vessel containing 1 molar lithium chloride solution as the eluent.

After about 2 hours the eluent had reached about 16cm. The foil was removed and dried, then localisa-tion of the substance spots under UV light at 254 nm was noted and the retention factor determined.

This is calculable from the relationship between the distance run of the substance core area (Sx) to the distance run by the solvent (Sf) (Rf = Sx/Sf).

The Rf values were 0.6 for AMP, 0.45 for ADP and 0.2 for ATP, which is consistent with reference data in the literature (13). The solutions treated with thermal disinfec-

tion and a cleaning step showed without exception the same run distance as ATP in a single spot. Hydrolysis to ADP or AMP was not determined. For hydrolysis to the extent of more than 10% the hydrolysis prod-ucts of ATP would be semi-quantitatively determin-able because of the intensity of the UV absorption. So there is no need to do quantifi cation using the UV-DC scanner.

Conclusion

The tests show that conditions of automatic repro-cessing do not hydrolytically destroy ATP. The ATP in the cellular components of blood are partly enzymati-cally broken down directly after soiling of the instru-ments by actual use and during the disposal/clean-up time. A time period of 30 to 60 minutes already leads to signifi cant breakdown (9). Any other ATP comes from possible residual soil and is more or less thor-oughly extracted and dissolved away by reprocess-ing. Thus it is not expected that ATP measurements should correlate with residual soil. |

Literature:

[1] Obee P et al.: Real-time monitoring in managing the decontamination of fl exible

gastrointestinal endoscopes. Am J Infect Control 2005; 33: 202-206

[2] Hansen D et al.: ATP measurement as method to monitor the quality of reprocessing

fl exible endoscopes. Ger Med Sci. 2004; 2: Doc 04

[3] Buchrieser V et al.: Presentation/Lecture WFHSS Conference, Creta 2009

[4] Iseli M.: Schnelltest bei der Leistungsbeurteilung von Reinigungs- und Desinfektions-

geräten, Master Thesis, Fachhochschule Bern, Juni 2013

[5] Heider D; Michels W: Biolumineszenz-Methode zum Nachweis von Kontamination.

aseptica 13(2); 2007:19-21

[6] Heathcote R, Stadelmann B: Measuring of ATP bioluminescence as a means of

assessing washer disinfector performance and potentially as a means of validating

the decontamination process. Healthcare Infection 2009; 14: 147-151

[7] Gorman M et al.: Human Plasma ATP Concentration. Clinical Chemistry 53(2); 2007:

318-325.

[8] Barlett G, Barnet H: Changes in the phosphate compounds of the human red blood

cell during blood bank storage. J. clin. Invest. 39; 1960:56-60

[9] Coade S, Pearson J: Metabolism of adenine nucleotides in human blood. Circulation

Research 65; 1989:533-537

[10] Brewer G, Knutsen C: A technique for the processing of blood samples for subse-

quent assay of ATP. Clin. Chim. Acta 14; 1966: 836-839

[11] Tabushi I et al.: Hydrolysis of ATP in chemical models. Nucleic Acid Research,

Symposium Series No. 10 1981, IRL Press Limited

[12] Köhnlein J et al. : Multicentre Trial on Standardisation of a Test Soil of Practical

Relevance for Comparative and Quantitative Evaluation of Cleaning Pursuant to EN

ISO 15883. ZentrSteril 2008; 16: 424-435

[13] Randerath K: Thin-Layer Chromatography 2nd ed., Academic Press 1966

Figure 2: Device to measure bioluminescence

4 November 2014 edition | Evaluation of ATP / bioluminescence method

Fig. 3: Chromatogram of AMP, ADP, ATP and the treated

ATP solutions

Users and reprocessors are confronted with a great challenge when trying to choose the "right" closed transport trolley system to optimise the reprocessing fl ow cycle for ev-eryday hospital use. This is because of the complexity of the subject area and the man-ifold details that need to be considered. The following explanation goes into the main themes here and in addition the most important criteria for selection, shown as a check list. This objectifi es the decision-making process for the right logistics sys-tem (individual to each hospital) and then discussions with potential suppliers in this area can be greatly simplifi ed.

The "right" logistics system has an ever increasing signifi cance in today’s hospital environment. With its help internal hospital process sequences are optimised and generally the full sum of daily work in the hospital is eased. The target for the reprocessing fl ow cycle is the confi guring of a closed process chain, which ad-heres to the most stringent hygiene standards.

Especially in the process sector sterilisation and for its interfaces, it is increasingly important to swiftly trans-

Criteria needed to choose a closed transport trolley system for an optimal reprocessing fl ow cycleM. Kögel

November 2014 edition | Criteria needed to choose a closed transport trolley system 5

Mathias Kögel

Geschäftsführer

Kögel GmbH

Hagenfeldstraße 4

75038 Oberderdingen

Germany

E-Mail: M.Koegel@mk-koegel.de

Internet: www.mk-koegel.de

| Authorport the reprocessed/sterilised medical devices in a protected environment from the reprocessing site (internal or exter-nal), to the operating area without recon-tamination. The transport of contami-nated medical devices from their site of use back to the reprocessing site is equally important.

To determine the optimally designed logistic system for each hospital and before the relevant decision to buy, a multitude of varying considerations must be weighed up.

As well as a wide range of different suppliers in the market, who vary in reliability, quality and price range, the main choice is between the two basic variants of trolley design in stainless steel or aluminium.

Transport systems made of stainless steel are noted for their markedly higher tolerance of high tempera-tures and of chemicals in comparison to aluminium versions. At the same time exterior trolleys made of stainless steel (Fig. 1) can themselves be more intensively reprocessed than a similar aluminium model.

Figure 1:

An example of a closed transport

trolley system made of stainless

steel with fl exible interior racks

from Blanco

6 November 2014 edition | Criteria needed to choose a closed transport trolley system

Figure 2: An example of

a closed transport trolley

system with fl exible and

fi xed interior racks made of

aluminium from Kögel

Aluminium transport systems, such as those sup-plied by Kögel are noted on the other hand for their markedly lighter weight. Aluminium trolley systems are roughly 1.5 – 2.5 times lighter than comparable stainless steel models. This makes the trolleys much easier to manoeuvre, so that especially when a trol-ley is loaded, personnel workload is considerably eased.

The corresponding weight savings are related not only to ergonomic advantages but likewise reduce transport costs between external reprocessers and the hospital. The ergonomic advantages simplify the daily handling of the trolley system and help the hospital management to maintain the continued productive effi ciency of its employees. A signifi cant point in fa-vour of the aluminium version (Fig. 2) is the gener-ally cheaper purchase price compared to a comparable stainless steel model.

As well as the choice of external material, the suit-ability of the trolley system for transport between the external reprocessor and the hospital or simply for internal transport matters and should be carefully

It is necessary to choose

between the two basic trolley

design variants – stainless steel

and aluminium.

considered. In order to protect the transported load optimally it is necessary to select types of wheels as well as locking mechanisms.

Furthermore it needs to be decided whether a logis-tical system with removable or fi xed interior racks/shelves is wanted. Flexible interior racks in the form of a Car-in-Car or shuttle system are ideal for case-related delivery to various operation specialties and guarantee a process-optimised and in particular hy-gienic transfer of the reprocessed instruments in the operating theatre environs. At the same time the sub-sequent collection of the contaminated instruments is likewise considerably simplifi ed.

The checklist on the following pages summarises the signifi cant options when deciding on the re-quired trolley system and thus facilitates the inter-nal hospital specifi cation, the possible subsequent invitation of tenders, as well as discussions with potential suppliers. |

November 2014 edition | Criteria needed to choose a closed transport trolley system 7

Question Model design Remark:

Topic: Holding capacity

What will the trolley be used for? In house or external transport

Which material is preferred? Stainless steel or aluminium model

How stable is the main frame?Is the trolley easy to open even when fully loaded and the fl oor is uneven?How high is the required maximum total load?

Are there any special requirements regarding cleanability of the trolley? Wipe disinfection/washing plant suitability and sterlisability

To what extent has the manufacturer avoided sharp edges and undercuts in order to provide the bestpossible handling safety and cleanability?Is rinse shadow expected in the interior, on the doors or between the main body and the doors?

Design of trolley and door inner surfaces (manufactured without joints)

Complete all-round door seal for maximum dust proofi ng and reduction of recontamination

Is moisture free drying guaranteed inside the trolley?

Required measurement/capacity of the trolley? Should containers/baskets be stored/transported in DIN or ISO dimensions? Do you want combined storage/combined transport of DIN and ISO containers?

3 STE, 6 STE or9 STE

Is individual colour coding e.g. to identify case trolleys required?

Exactly what fl oor levels normally have to be dealt with?

Topic: Requirements for reprocessing

What pH values are used in reprocessing?

Which cleaning materials are currently used for reprocessing?Have these cleaning materials been checked by the manufacturer for their suitability for stainless steeland/or aluminium trolleys?

Does the trolley need to be suitable for a washing plant?

Is the trolley or its interior intended to be sterilised?

Topic: detailed design

Have steps been taken to improve water run-off from the trolley roof?Is the trolley (rain) water-proof (especially important for external reprocessing)?

Is the trolley very noisy when pushed fully-loaded?

What locking system is necessary? Simple turning lock/hole for lead-sealing/ lockable lock/2 point central lock

Is a mobile inner rack necessary?Shuttle-/Car-in-Car-SystemTransfer trolley (models: can move in 1 or 2 directions)Unloading platform, fi xed interior frame

Is optimal dust proofi ng via a complete all-round door seal required?

Are all-round wall bumpers required? If so, above and/or below?Are roof bumpers required for possible transport in a lorry?

Should the inner racks be height adjustable? If so, at what intervals?

Should the mobile inner rack be able to be pushed sideways and/or straight?

Does there need to be something to stop the transported containers from slipping out?

What special requirements for the coupling mechanism between the take-over trolley and the storagetrolley for removing the push-in rack are planned to ensure optimal handling safety?

Which type of wheels is required (for the storage and take-over trolley?)

2 steering rollers and 2 fi xed rollers/ special resistance to wear and tear/ central arresting device/single brake or central stop/direction-fi xable rollers, especially for use in a train of trolleys or in combination with pass-through cabinet/smoothly running rollers/sterilisable rollers/antistatic roller type/postitioning of the rollers (parallel alignment or crosswise position for simple turning when stationary)

Is a train of trolleys required/intended?

How wide should the doors open and be stopped from opening further? 255° and/or 270°

Is individual colour coding required, for example to identify case trolleys?

What unevenness or levels of fl oors, steps etc. have to be navigated?

Topic: required fi ttings to streamline/facilitate the cycle

What fi ttings and equipment should be planned for the hospital daily routine?

Coupling and tow-bar- extra friction reduced coupling for lurch free train operationLabel holder A4, label holder A5, paper clipEarth cable/central brake/wheel lock/direction lockVertical or horizontal pushing handle (on one side or both sides) Height of handle positionSupport grating/wire baskets/Support shelves (perforated if necessary)/containersRoof gallery as additional storage areaAdditional coding, for example on the bumpers

The Bowie and Dick Logger EBI 16 made by ebro is a further developed version of the previous model EBI 15 and is suitable for conducting the Bowie-Dick test and the load monitoring PCD as an electronic alter-native to chemical indicators.

The Bowie and Dick Test System EBI 16 – consisting of the data logger EBI 16 and the software Winlog.med or Winlog.valida-tion – is an innovative and economic way of conducting quality testing of a steam steriliser. The system is able to recognise and document errors during the sterilisation process. The performance of the Electronic Bowie and Dick Test EBI 16 has been eval-uated in the laboratory by ebro Electronic in accordance with DIN EN 2851 and DIN EN ISO 11140-4:20072.

Results of the tests

To test the EBI 16 system the Standard EN 11140-4 section 6 was consulted. The requirements from Table 1 section 6.2 were taken as a test plan. The test cycles are described carefully in Appendices B1, B2 and B3. The test conditions required by the standard such as "Error-free cycle" (B1, B2 and B3), "Error cycle, modifi ed deaeration" (B1 and B2), "Error cycle induced leakage" (B1) and "Error cycle air injection" (B1 and B3) were reproducibly recognised and docu-mented by the data logger system.

The Bowie and Dick Logger EBI 16

The Bowie and Dick Logger EBI 16 is a measuring appliance equipped with two temperature sensors and a pressure sensor. Data is stored in an internal mem-ory with a capacity of 6,960 values per channel. The rate of measurement is fi xed once per second.

Data transfer takes place via the interface (base sta-tion) EBI IF-150 to the computer, where the data are

Innovative monitoring of sterilisation using the new EBI 16 Bowie and Dick Test Data LoggerR. Streller

Robert Streller

Wissenschaftlich-Technische

Werkstätten GmbH

Geschäftsbereich ebro Electronic

Peringerstraße 10

85055 Ingolstadt

Germany

E-Mail: ebro@xyleminc.com

Internet: www.ebro.com

| Author

evaluated by the software Winlog.med or Winlog.vali-dation. The defi nite result of the Bowie and Dick Test is shown either as "Passed" or "Failed".

The progression of pressure, temperature and time is depicted with the help of a graph, where the theoreti-cal temperature of the steam is incorporated into the evaluation. The sterilisation cycle is marked as errone-ous in the data bank and possible causes of the error are shown. The results of measurement

The tests carried out using test cycles with deaeration via pressure change in a vacuum, transatmospheric pressure change or pressure change with overpres-sure, comply with the requirements of the standard ISO 11140-4 Appendix E. For the tests, the errors air injection, leakage and modifi ed deaeration step (defi -cient evacuation) are simulated in the chamber.

The errors are checked using a standard test pack ac-cording to EN 11140-4 Appendix K. The evaluation of the errors follows according to EN 11140-4 Ap-pendix F. The consequences of these simulations are defi ned temperature changes that occur as a reaction to the pre-set error.

For these test methods the parameters of the sterilisa-tion programme are strictly dictated by the standard. If these limits are adhered to a sterilisation cycle with error-free conditions can be run. A typical error-free sterilisation cycle is recognised and marked as "Passed". The documentation lists all relevant data as well as the progression of temperature, pressure and time, via the ebro software. The EBI 16 data logger is positioned in the geometric centre of the sterilisation chamber during all measurements.

Air injection error (EN11140-4 Appendix L)

For the simulation of air injection (required for cy-cle B1 and B3) approximately 400 cubic cm of air is

8 November 2014 edition | Innovative monitoring of sterilisation

1 DIN EN 285:

1997 Sterilization – Steam

sterilizers – Large sterilizers

2 DIN EN ISO 11140-4:2007

Sterilization of health

care products – Chemical

indicators – Part 4: Class 2

indicators as an alternative

to the Bowie and Dick-type

test for detection of steam

penetration.

forced into the sterilisation chamber during heating – at approximately 100kPa (B1) or 125 kPa (B3). The EBI 16 system recognises this error.

Leakage as error

Here there is a defi ned connection provided by a valve between the sterilisation chamber and the external air. The error is set up using a vacuum test at a leakage rate of 140 Pa/minute. The test cycle B1 activates this error condition. The leakage is registered using the EBI 16 system. Defi cient evacuation as error

For the simulation of this error (cycle B1 and B2) the sterilisation chamber is simply insuffi ciently evacu-ated. The switchover point in the underpressure is raised by 15 kPa for cycle B1 and by 12kPa for cycle B2. In this way defi cient evacuation is realised. The Bowie and Dick Test System EBI 16 detects the error surely and reliably.

Summary

This test proves that the Bowie and Dick Test Sys-tem EBI 16 clearly recognises the errors specifi ed in the test conditions of the standard EN 11140-4, that can occur during the steam sterilisation pro-cess, and that this electronic system is capable of monitoring and documenting the sterilisation pro-cess. A defi cient sterilisation cycle is recognised and marked as "Failed". |

The standard Start screen

illustrates the simple imple-

mentation and evaluation

of routine monitoring tests

using ebro software.

Technical data from the EBI 16 Bowie and Dick Test Data Logger

Temperature measuring range 0 °C to +150 °C

Temperature accuracy ±0.1 °C

Pressure measuring range 0 mbar to 4,000 mbar abs.

Pressure accuracy ±15 mbar

Sensors 1 piezoresistive pressure sensor

2 Pt 1000 temperature sensors (platinum)

Certifi cate Factory calibration certifi cate

November 2014 edition | Innovative monitoring of sterilisation 9

One of the oldest methods used in opera-tive fracture treatment is closed reposi-tioning (lat. Repositio = restore) and fi xa-tion using a Kirschner wire / rotating guide wire. This method has been in use since the 1920s and is still used regularly today. So far Kirschner wires made of stainless steel (e.g. EN steel no. 1,4301) and pure titanium (material no. 3,7034) are licensed on the market.

Kirschner wires are used amongst other things for percu-taneous intramedullary splinting (e.g. metacarpals) or for percutaneous pinning. Percutaneous pinning is the term for "securing a fracture by introducing a Kirschner wire". Due to the great fl exibility of Kirschner wires, these methods can also be used where a movement-stable pro-vision (e.g. using fi xed angle plates) is not possible.

On one hand the fl exibility of the Kirschner wires as described, is advantageous, on the other hand these wires are diffi cult to reprocess and store. Manufactur-ers only supply a few guidelines, which are in principle easy to follow: - Reprocessing of brand new Kirschner wires before

their fi rst use- Transport packaging, protective caps etc. are not

suitable for sterilisation - Automatic washing / disinfection is preferable. Re-

processing in a WD is possible without restrictions.

In addition according to manufacturers’ instructions, keeping to the AKI guide-line ("Proper Instrument Reprocessing") the RKI recommendation ("Require-ments for hygiene when reprocessing medical devices") as well as the relevant/pertinent standards and statutory regula-tions, is suffi cient to guarantee optimal and reliable reprocessing. Nonetheless the everyday user is confronted with some problems that manufacturers gen-erally cannot help with:

Reprocessing Kirschner wires – problems and their solutionsJ. Keller

10 November 2014 edition | Reprocessing Kirschner wires – problems and their solutions

- How can I safely fi x the sensitive equipment in the sieve/container (because of its light weight and small diameter) without it being washed out of the container?

- How can I attain an optimal reprocessing result with the least possible rinse shadow/residual moisture?

- How can I label the often tiny diameter variations and store the Kirschner wires suitably?

Some possible answers to these problems are depicted in Figure 1. Some establishments store Kirschner wires in sterile bags after reprocessing. However reprocess-ing bags in the WD is contraindicated and so this only solves the storage problem. In such establishments re-processing in the WD takes place usually by bundling with rubber bands or container lead seals. These "bun-dles" are laid directly in the sieves waiting for reprocess-ing. However due to the "bundling" not all the wires are washed evenly (rinse shadow), which is a huge disadvan-tage. In addition to increased amounts of rubbish pro-duced and additional costs for sterile bags, labelling with length and/or diameter has to be redone every time.

Another approach is the reprocessing and storage of Kirschner wires in ordinary "tubes" or "salt cellars" (Figure 2). Here fi xation and storage is guaranteed to be safe and individual labelling of the container is like-wise possible. One disadvantage here is however, that due to the small and few holes, washing of the single wires in the WD is likewise not guaranteed. Therefore

Julia Keller

MEDSolutions

Kögel GmbH

Germany

Phone: + 49 (0)7045 982-51

Fax: + 49 (0)7045 982-22

E-mail: j.keller@mk-koegel.de

Internet: www.mk-koegel.de

| Author

Figure 1: Tube drill wire dispenser and storage in

sterile bags

November 2014 edition | Reprocessing Kirschner wires – problems and their solutions 11

washing and disinfection of the wires should really take place out of the tubes. Furthermore there is the problem of residual moisture that is solved in most establishments by subsequent "blowing dry". A fur-ther disadvantage is that the tubes cannot be seen into i.e. checking the number and lengths of the wires is only possible after opening.

Another approach to solving the problem is depicted in Figure 3. The drill wire dispenser depicted here

Figure 3: Storage of drill

wires in drill wire dispens-

ers with jolt preventer and

size test holes

Sources:

[1] A.Rüter u.a. (Hrsg.): Unfallchirurgie/Trauma

surgery. 1.Aufl age.

Urban & Schwarzenberg, München – Wien –

Baltimore, 1995, ISBN 3-541-17201-0.

[2] http//www.berger-surgical.de

Gebrauchsanweisung/Instruction manual

(IFU-20.1) Kirschnerdrähte/Kirschner wires

Figure 2: X-ray photograph of a plurifragmentary fracture

of the distal lower arm after Kirschner wire pinning and

external fi xation

can be used in the complete reprocessing cycle. The Kirschner wires are put in sorted according to their diameters, and secured by a hinged lid. Falling out or being washed out is thus prevented. Due to the open construction thorough washing and also drying of the wires can be attained. Later on when the single Kirschner wires are removed the assisting medical technologist checks the diameters once more, using the lasered test holes under the diameter labelling.

The methods described here are surely only a fraction of the methods used in practice. Perhaps one or two readers will recognise their own methods or can try out some of the tips given. |

12 November 2014 edition | Water hygiene and the automatic reprocessing of endoscopes

Water is one of the most important utilities in every hospital, including for manual and automatic reprocessing of fl exible endo-scopes. These fragile optoelectronic appli-ances are thermolabile and the maximum temperature permitted for their reprocess-ing is 60 °C. Therefore water quality is para-mount for reprocessing. Even a tiny number of germs in the water can lead to biofi lm for-mation with problematic pathogens. There-fore certain parameters for water sampling as well as systematic research into the causes of any problems are absolutely vital.

According to the German drinking water ordinance (TrW-VO) the hospital takes on responsibility for water quality at the takeover point from the public

water supply. The TrW-VO requires a microbiological water quality of less than 100 CFU/ml (< 100 colony-forming units per ml).

The presence of germs such as Escherichia coli, entero-cocci or coliform bacteria is not tolerated. However there is no requirement in the or-dinance regarding Pseudo-monas aerigunosa.

Water hygiene and the automatic reprocessing of endoscopesC. Roth

For automatic reprocessing of endoscopes some of the quality requirements are much stricter. The Guide-line of the Robert Koch Institute stipulates drinking water quality for the fi nal rinse (<100 CFU/ml) and the absence of pathogenic germs such as Pseudomonas in particular. However the DIN EN ISO 15883-4 and the German Guideline for validating automatic washing and disinfecting processes for reprocessing fl exible endoscopes drafted by the Guideline group of the DGKH, DGSV, DEGEA, DGVS and AKI, require a considerably greater degree of cleanliness for the fi nal rinse water. Here < 10 CFU per 100ml (0.1 CFU/ml) is required, which is a thousand times higher than the requirement for the German drink-ing water ordinance TrW-VO. Since 2010 the German Guideline prescribes the annual validation of washing and disinfecting appliances for fl exible endoscopes (RDG-E) and here a maximum of 20 CFU per endo-scope canal is permitted. This value is the equivalent of 1 CFU/ml.

Germs usually originate in the domestic water system

So where exactly are the risks of contamination to be found? Experience shows that the actual origin is usu-ally not found within the WD-E itself. If there are germs in the hospital drinking water, these often come from the domestic supply. Biofi lms with a high persis-tence of microorganisms can form in the dead ends

Christian Roth

Produktmanagement Flexible Endoskopie – CDS

Medical Systems

OLYMPUS DEUTSCHLAND GMBH

Wendenstr. 14 - 18

20097 Hamburg

Germany

E-Mail: Christian.Roth@olympus.de

| Author

Figure 1: Macromolecules such as proteins establish

themselves next to water and ions amongst other things

in ascending and dead-end pipes and siphons.

Thus biofi lms with a high persistence of microorganisms

can form.

Source: Christian Roth

November 2014 edition | Water hygiene and the automatic reprocessing of endoscopes 13

of pipes, siphons and ascending pipes. These compo-nents of infra-structure are often impossible to dis-infect, so that sometimes the only effective and sus-tainable measure is to completely replace them. One particularly dangerous bacterium in connection with endoscopy is Legionella, which can become estab-lished in water pipes that have been unused for some time. Contamination with Legionella can cause severe pneumonia via bronchoscopy. The other candidate on the list of potential pathogens found in the water sup-ply are pseudomonads. These aerobic, gram negative bacteria establish themselves preferentially in biofi lms and can cause pneumonia, gastrointestinal illness or middle ear infections. About 10% of all nosocomial infections are caused by these bacteria.

Upstream sterile fi lters helpful

Modern reprocessing machines for fl exible endo-scopes are therefore fi tted with various mechanisms to minimise this risk. So that the fi nal rinse water com-plies more or less with the German Guideline, many hospitals and gastroenterological specialist practices fi t sterile fi lters for the rinsing water of the appliances. These fi lters substantially reduce the probability of recontamination. Additional safety is offered by WD-Es that are fi tted with a UV lamp to kill germs in the feed water. The disinfection process is then carried out using top-quality reprocessing chemicals such as for example peracetic acid (PAA), which among other things offers very good effectivity against biofi lms and dependably kills microbes such as pseudomonads.

Figure 2: Optimised processing of rinse water e.g. with the help of UV

lamps installed in WD-Es, which dependably kill germs in the feed water.

Source: Olympus Deutschland GmbH

Figure 3: In certain washer-disinfector

appliances for fl exible endoscopes, for

example the current ETD system from

Olympus, the disinfection process is

carried out using top-quality peracetic

acid (PAA) reprocessing chemistry.

Source: Olympus Deutschland GmbH

Thanks to peracetic acid the washing process can be carried out at low temperatures, which is ideal for thermolabile endoscopes.

Correct water sampling technique

If a hygiene problem in the drinking water is suspected, then it is essential to take a water sample effectively and correctly. Basic requirements are that the sampler has clean hands and uses a sterile container. After those considerations it is important that the sample should be taken as near as possible to the user, for example, from the connection of the washer-disinfec-tor appliance. The timing of sample-taking can also be critical. Ideally the sample should be taken early in the morning, before any water has fl owed through the system. It is also important that no attachments should be unscrewed. At sample taking no water should be allowed to run off, so that a true result can be obtained. Correct and spatially close sample taking like this helps in the responsible approach to the sen-sitive topic of water hygiene for automatic endoscope reprocessing and helps to identify and remove pos-sible problems quickly. |

14 November 2014 edition | Reprocessing recommendations – comparing AAMI standards with the 'Red Book‘

Recommendations about the re-processing of reusable medical devices are made by AAMI stan-dards, such as ANSI/AAMI ST79,1 which covers steam sterilization, and AAMI technical information reports, such as TIR12,2 TIR30,3 and TIR34.4 The focus of each document differs, but the mainte-nance of devices, their cleaning,

and workers’ safety are covered, in varying degrees, by all of them. Although mainly used in the United States, AAMI documents are also considered by authorities in other countries and scientifi c organizations in the drafting of their own standards or guidelines.

The brochure Proper Maintenance of Instruments, also known by its nickname, the Red Book (or bro-chure),5 is a collection of recommendations about the reprocessing of medical instruments. This brochure, in its ninth edition, is prepared and updated by various medical industry experts who make up what’s called the Instrument Preparation Working Group, which was established 35 years ago in Germany. The objec-tive of this document is the compilation and publica-tion of practical information on the proper reprocess-

Reprocessing recommendations – comparing AAMI standards with the 'Red Book'H. Biering

ing of reusable medical devices, with a special focus on the maintenance of medical instruments. It is available in 19 languages and is commonly used in many coun-tries in Europe, Asia, and Latin America.

The recommendations in AAMI documents and the Red Book are not always identical, leading to confl ict-ing guidance. For that reason, members of the Instru-ment Preparation Working Group, assisted by the working group’s junior expert team, compared recom-mendations for each reprocessing step in the AAMI documents ST79, TIR12, TIR30, and TIR34 to the steps in the Red Book, and highlighted differences rel-evant to the maintenance of instruments.

Comparison Procedure

The stages for medical device reprocessing were divided into the following groups:• Preparation for cleaning and disinfection• Manual and automated cleaning and disinfection• Inspection and care• Packaging• Sterilization• Storage

Additional groups covered recommendations related to:• Treatment of new and repaired instruments• Treatment for returned goods• Surface changes on instruments

Recommendations for each step in the four AAMI documents and the Red Book were compared by the subgroups. The complete team evaluated the fi ndings in the next working stage, and ranked them as major and minor deviations, or as opportunities for improve-ment to the Red Book or to the AAMI documents.

Results

The comparisons show that the majority of recom-mendations in the four AAMI documents and the Red Book are the same or similar with respect to the

Red, white, and blue:

While they have different

covers, a comparison of

standards documents

related to reprocessing

in the United States and

abroad fi nds many

similarities.

Dr. Holger Biering

Gladiolenstr. 19

41516 Grevenbroich

Germany

E-Mail: holger.biering@web.de

| Author

November 2014 edition | Reprocessing recommendations – comparing AAMI standards with the 'Red Book‘ 15

maintenance of medical devices. Some examples of the differences and the group’s evaluation can be seen in Table 1. In some cases, procedures are described in more detail in the AAMI documents. On the other hand, the Red Book recommends careful placement and handling of instruments after use, whereas AAMI documents do not mention this. The Red Book also contains a more detailed chapter covering surface changes on instruments, describing types of changes, origin and causes, treatment recommendation, pre-ventive measurements, and risk analyses.

Other minor deviations are linked in most cases with local requirements i.e., effi cacy range of disinfectants, preferred cleaner, or parameters for steam steriliza-tion. Major deviations were identifi ed in two areas: • Transport of contaminated items from the point

of use to the decontamination area • Lubrication of surgical instruments with moving

parts, hinges, and box locks

Transport of Contaminated Items

AAMI documents recommend what the Red Book defi nes as "moist disposal": Contaminated items "should be kept moist in the transport container by adding a towel moistened with water (not saline) or foam, spray, or gel product specifi cally intended for this use. Transporting contaminated items in liquid is not recommended."3

The preferred transport option in the Red Book is the so-called "dry disposal." If "wet disposal" is ap-plied, the Red Book and AAMI documents advise the immersion of contaminated items in a combined detergent-disinfectant solution with no protein-fi xing effect. For this reason, detergent-disinfectants con-taining aldehyde should be avoided.

"Because of the corrosion risk and cleaning factors, long intervals between instrument use and processing for reuse (e.g., overnight or over the weekend) should be avoided, irrespective of the disposal method used (i.e., wet or dry). Experience has shown that in the case of dry disposal, in practice intervals of up to six hours pose no problem."5,6 (It is worth noting that device manufacturers recommend that reprocessing begin as soon as possible.)

Lubrication of Surgical Instruments

AAMI documents recommend immersing "instru-ments for a few moments in a water-soluble lubricant solution or spraying them with a water soluble lubri-cant solution."3 Additionally, "Silicone- or oil-based lubricants are not recommended."3

Preferred treatment in the Red Book is the "tar-geted application of instrument lubricant to the joints, hinges, locks, threads or friction surfaces of

Table 1.: Examples of

Varying AAMI and Red Book

Reprocessing Recommen-

dations

16 November 2014 edition | Reprocessing recommendations – comparing AAMI standards with the 'Red Book'

instruments such as clamps, scissors or punches...."5 Furthermore, the Red Book describes the require-ments for care agents as follows: • Paraffi n/white oil basis • Biocompatible in accordance with the current European or United States Pharmacopoeia • Suitable for steam sterilization and vapour- permeable 5

Discussion

It is no surprise that most of the recommendations in AAMI documents and in the Red Book are the same or similar. All of these documents are prepared by teams of experts with much experience in the re-processing of reusable medical devices. Nevertheless, some minor and two major deviations were identifi ed in this comparison. The fi ndings with respect to the more detailed and precise procedures and appendices of the AAMI documents will be used to improve the next issue of the Red Book.

Likewise, those who draft AAMI standards and tech-nical information reports might consider integrating the advice for careful placement and handling of medical instruments. "Careless dropping can damage instruments. For example, the hardened (tungsten car-bide) tips of scissors may come off, or small clamps may be bent." 5

Minor deviations related to the preferred use of chemicals or steam sterilization conditions are mainly caused by different requirements in local markets. This is not the case with respect to the two major deviations related to the transport of contaminated medical devices and the care of surgical instruments.

Wet, Moist, or Dry Disposal

"Wet disposal" was once the preferred transport op-tion of contaminated instruments in some European countries. In most cases, detergent-disinfectants are used. The advantage of this option is the combina-tion of precleaning effects with the reduction of vi-able microorganism on the contaminated items. This procedure reduces the occupational risk to personnel during manual cleaning. The precondition for apply-ing this procedure is the use of waterproof contain-ers. Disadvantages are the handling and transport of

heavy containers, the amount of waste water, and the risk for carry-over of foaming cleaner into the washer-disinfector.

"Dry disposal" has been the preferred option in most of Europe for the past 15 years. Dry transport causes no problem with respect to cleaning ability and mate-rial compatibility when the transport time is less than six hours. Hospitals with integrated sterilization de-partments are able to manage this interval.

Sterilization departments have been increasingly out-sourced in some European countries in the past couple of years. External sterilization departments offer the service for multiple hospitals with long transport dis-tances, which may result in transport times exceeding six hours. The "moist disposal" option is the most fre-quently used procedure in those cases. Investigations about material compatibility of stainless steel and ano-dized aluminium with foam sprays for moist disposal showed that for most of the products, no material damage/corrosion occurred at exposure times longer than six hours.7 One product caused pitting corro-sion at a contact time longer than six hours. The cleaning ability of these foams at longer storage time was not the objective of this study. Some side obser-vations lead to the conclusion that the moisturizing and rinsing behaviors of foam cleaners at contact time longer than six hours should be investigated in further studies.

Wet, moist, and dry transportation of contaminated items have advantages and disadvantages, and should be mentioned in the standards/guidelines. Depend-ing on the circumstances at point of use the preferred option should be selected by the hospital. The moist disposal option will be considered in the next issue of the Red Book. Nevertheless the Instrument Prepara-tion Working Group will continue to recommend the dry disposal as the preferred option when transporta-tion times are less than six hours. Furthermore, it is suggested that the AAMI document integrate descrip-tions for dry and wet disposal options.

Wet, moist, and dry transportation of

contaminated items have advantages

and disadvantages, and should be

mentioned in the standards/guidelines

November 2014 edition | Reprocessing recommendations – comparing AAMI standards with the 'Red Book‘ 17

Instrument Lubrication

The fi ve documents compared describe three pro-cedures for lubrication of surgical instruments with moving parts, joints, hinges, locks, and threads: • Immersion of instruments in lubricant solution • Spray instruments with lubricant solution manually

or automated, i.e., in washer-disinfectors • Targeted application of lubricant solution

Targeted application is the preferred procedure in the Red Book. It is most effective in the lubrication of moving parts, enhancing cleaning ability, 8 and has fewer side effects.

Immersion and spray of instruments, i.e., in the fi nal rinse stage of automated washers are not recommend-ed by the Instrument Preparation Working Group for the following reasons: • The amount of lubrication agent on the moving

parts is not high enough, especially in the case of very effective cleaning procedures.

• Lubricant agents on open instrument surfaces can cause colored deposits in the steam sterilization process.

• Lubricant agents can cause damage on plastic and rubber parts of washer-disinfectors.

Behaviors of lubricant agent are described more pre-cisely in the Red Book. The term "water-soluble lubri-cant solution" and the discussion of oil-based lubricants sometimes leads to confusion for non-native speakers. Most of the lubricant solutions are based on paraffi n-oil combined with surfactants and corrosion inhibitors. They are available as lubricant solutions or sprays.

It is suggested that AAMI expert groups consider the more detailed description of lubricant agent and consider changing the preferred procedure to targeted application.

Summary

The comparison of four AAMI documents and the Red Book shows a high level of consistency with re-spect to the maintenance of reusable medical devices and in their reprocessing procedures. The Instrument Preparation Working Group will consider the fi ndings related to a more detailed and precise description of some procedures in the next issue of the Red Book.

AAMI working groups should consider modifi cation of the recommendations for transportation of contam-inated items and for the care of surgical instruments. |

Acknowledgement

The comparison of the four documents was perfor-med by the following senior and junior experts of the Instrument Preparation Working Group: Klaus-Peter Becker (Ecolab), Holger Biering (Consultant), Christian Bullmann (Miele), Hans-Jörg Drouin (MMM), Robert Eibl (MMM), Wolfgang Fuchs (Aesculap), Rudolf Glasmacher (Ecolab), Ina Haacke (Dr.Weigert), Helmi Henn (Richard Wolf Endoskope), Ulrich Junghans (Fachhochschule Köthen), Karl Leibinger (KLS Martin Group), Winfried Michels (Miele), Sebastian Niebuhr (Ecolab), Ursel Oelrich (Aesculap), Verona Schmidt (Dr.Weigert), Matthias Schöttler (Ecolab), Michael Sedlag (Miele), Jürgen Staffeldt (Dr.Weigert), Bernd Tangel (Richard Wolf Endoskope), Matthias Tschörner (Dr.Weigert), and Matthias Warken (Aesculap).

References:

[1] ANSI/AAMI ST79:2010 & A1:2010 & A2:2011 (Consolidated Text), Comprehen-

sive guide to steam sterilization and sterility assurance in health care facilities.

Association for the Advancement of Medical Instrumentation. Arlington, VA.

[2] AAMI TIR12:2010, Designing, testing, and labeling reusable medical devices for

reprocessing in health care facilities: A guide for medical device manufacturers.

Association for the Advancement of Medical Instrumentation. Arlington, VA.

[3] AAMI TIR30:2011, A compendium of processes, materials, test methods, and

acceptance criteria for cleaning reusable medical devices. Association for the

Advancement of Medical Instrumentation; 2011. Arlington, VA.

[4] AAMI TIR34:2007, Water for the reprocessing of medical devices. Association for

the Advancement of Medical Instrumentation. Arlington, VA.

[5] Instrument Preparation Working Group. Proper Maintenance of instruments. 9th

revised ed. Morfelden-Walldorf (Germany): Arbeitskreis Instrumenten-Aufberei-

tung, 2009. Available at: www.a-k-i.org/index.php?id=11&L=1. Accessed April

11, 2012.

[6] Sonntag HG, Werner HP. Arbeitstagung Hygiene in der zahnaerztlichen Praxis. Hyg

Med. 1980;5:487-494.

[7] Biering H, Fuchs W, Staffeldt J. Analysis of Stainless Steel and Anodized Alu-

minium Material Compatibility with Foam Sprays Used for Keeping Used Surgical

Instruments Moist. Zentr Steril. 2010;18:240-243.

[8] Project Group Cleaning, Kirmse G. Investigations About Reproducible Cleaning of

Instruments Based on a Worst-Case Model. Zentr Steril 2011;19:26-36.

This article was originally published in the May/June 2012 issue of BI&T (Biomedical Instrumentation & Technology), a bimonthly, peer-reviewed journal from the Association for the Advancement of Medical Instrumentation, www.aami.org. Posted (or reprinted) with permission. Any other distribution of AAMI-copyrighted material requires written permission from AAMI.

18 November 2014 edition | Testing cleaning of problematic and complex instruments – significance of manual pre-cleaning

Personnel in CSSD departments know from experience whether a certain instru-ment or instrument set can or cannot be loaded straight onto the loading trolley of the WD and put through the on-site wash-

disinfection process, resulting in satisfactorily reprocessing. The operating instructions must defi ne which instru-ments need pre-treatment such as brushing, soaking, ultra-sound treatment etc., for an adequate cleaning result to be reached after automatic processing. Here we are talk-ing in the fi rst instance about optical absence of residues.

Testing cleaning

Some of those critical instruments are often not included in the performance tests of automatic re-processing, where a semi-quantitative or quantitative test for residual protein is conducted. Examples here are bone punches or medullary cavity drills that are not of take-apart construction. It is not easy to elute the instruments for sample taking and protein proof. Ideally, to be acceptable, it is necessary to determine residual soil present as far above 50% as possible. But more complex procedures are needed. The bone punch for example, has to be put functional end fi rst into a test tube containing a few millilitres 1% SDS solution at pH 11. Next the test tube with the instrument is fi xed to a stand, then submerged in an ultrasound bath and while being manually agitated, is treated with ultrasound (Fig.1). To extract a sample from the medullary cavity drill it is necessary to place it, for example, in a tube closed at both ends, with the tube curved so that the crevice areas of the drill are open. Then protein is extracted on a laboratory shaker. This is repeated three times, after rotating the

Testing cleaning of problematic and complex instruments – signifi cance of manual pre-cleaning

W. Michels

Dr. Winfried Michels,

c/o Miele Professional

Carl-Miele-Str. 29

33332 Gütersloh

Germany

E-Mail: winfried.michels@miele.de

| Author

instrument/tube a further 90° and clamoing it each time (Fig.2). The time outlay is considerable and be-sides, personnel do not always have access to these techniques for the performance test. Regrettably, ex-actly these critical instruments are often not tested. If they were, it would soon become obvious that the cleaning process does not deliver acceptable results. For the instruments named as examples, it is their construction that makes it necessary to defi ne the procedures described for sample taking, or even to use them as manual pre-treatment for the automatic process, in order to attain adequate results at last.

These are only two examples of the problems of cleaning and testing problematic instruments. How-ever, in reality at performance testing, these instru-ments are only too gladly left out.

Figure 1: Sample taking with ultrasound support for a punch

November 2014 edition | Testing cleaning of problematic and complex instruments – significance of manual pre-cleaning 19

Figure 2: Sample taking for a medullary cavity drill, also a

possible pre-treatment

Signifi cance of pre-treatment using robot instruments as an example

Robot shaft instruments have come under the spot-light of the relevant authorities. This is partly because these instruments were sent to laboratories and tested (in a dubious way) in order to verify their adequate cleaning as objectively as possible (aseptica 18 (2012), Volume 3: 20-21). From an expert point of view the results could not be trusted. Robot instruments stand for High-tech and therefore set a standard so that academics are also interested in them.

Looking at these instruments, we fi nd a very com-plex structure at the functional end. There are many contacts between several materials, which are very close to, or on top of each other. Many surfaces are more or less inaccessible for the wash solution. It is at least equally as complex as the gears of a dental drive system, however with the difference that the degree of contamination and its quality can be much more problematical.This leads up to the coagulation instruments with thermally fi xed pro-tein. To clean the distal functional end in a WD, the loading trolley would need to have drive systems so that the Bowden cables, and therefore the functional end, are continually agitated during the process and the contact surfaces are repeatedly made accessible. This would be technically very laborious and too costly. Because robot instruments with a coagula-tion function cannot undergo pre-treatment with hydrogen peroxide solution (as is standard in MIS) due to material incompatibility, the manual removal of these adhesions with brushes is required, com-bined with moving the Bowden cables. Not before the optical cleanliness of the functional part is at-tained manually, can the automatic process of fi ne cleaning i.e. reduction of residual protein, be en-sured at a suitable level.

A further critical area for these instruments is the inner distal shaft area with the seal to the functional part. In the worst case scenario a few hundred microlitres of blood could get into this area. To secure cleanability, it is necessary to fi ll this cavity immediately after use with an enzyme cleaner, using a disposable syringe via the fl ushing canal. It has proved constructive in manual pre-treatment, for the cleaning solution to be renewed at time intervals, until the removed solution

is relatively colourless and thus the subsequent fi ne cleaning in the WD can succeed. Experience from performance tests with actual instruments from real use show that in this way adequate cleaning results can be obtained.

Testing the critical distal part of robot instruments

The 8mm instruments can be used in the robot and then reprocessed up to ten times. To test the cleaning results of these actual robot instruments, they were manually and then automatically reprocessed after their fi nal use, as laid down in the operating instruc-tions. There was a difference however, in that the instruments were removed immediately before the thermal disinfection stage, freed from excess water using compressed air and put into a foil package and deep frozen. From the point of view of risk to patients from renewed use, the instrument parts de-fi ned as particularly critical are the distal metal part and the functional end including the inner cylinder of the shaft end with Bowden cables. To detach this part of the instrument, the casing cap is levered off

20 November 2014 edition | Testing cleaning of problematic and complex instruments – significance of manual pre-cleaning

the instrument being investigated, using a screwdriver. The Bowden cables are severed at the control wheels with a fi ne wire-cutter. They are then freely rotatable. Now the metal distal part can be pulled out of the shaft pipe and the Bowden cables severed similarly with wire-cutters, about 5mm before the metal distal part. With the help of an optical magnifying glass the functional part of the metal distal part, and in particu-lar the inner cylinder where the Bowden cables pass through to the functional part, is carefully checked. No residual soil should be visible.

The distal part is now placed in a plastic tube and 2ml 1% SDS solution pH 11 is pipetted in and the tube lid screwed on. This is extracted for 15 seconds in the vortexer, the tube is left to soak for 10 minutes, then vortexing and soaking is repeated twice more. The foam is allowed to settle, the tube opened and the dis-tal part is removed with a pair of tweezers. An aliquot of the solution is taken for analysis e.g. on site with the Miele Test Kit with refl ectometric measurements. For routine checks one can intensively shake the closed tube manually instead of using the vortexer. The test can also be orientated with the haemoglobin test (microhaematuria) (aseptica 18 (2010), Volume 4:14-16).

Usually the results for this instrument part, which has a large surface area, (this should be taken into account for the evaluation), lie at signifi cantly less than 50 μg equivalent BSA (Bovine serum albumen). This seems adequate when taking into account the estimated total area. The need for an area-related evaluation arises, because only thus is it possible to compare possible

Figure 3: The distal metal part is severed

results from, for example, chalazion clamps from ophthalmological surgery and orthopaedic medullary cavity drills. The standard committee ISO TC 198 WG13 on this procedure has approved this and the Guideline group for the validation of processes for fl exible endoscopes has also taken it into account. It sim-ply isn’t possible to use a blanket criterion of < 100 μg and lump everything together. After all, for pollutant concentrations we don’t state a volume per ocean or lake, because concentration is relevant to toxicity.

Summary

Reprocessing robot instruments consists in a combina-tion of a manual as well as an automatic process. The results of the automatic process are absolutely depen-dent on the diligence of the manual pre-cleaning and pre-treatment. Result deviations are therefore much more likely to be caused by the partially standardisable and not easily reproducible manual procedure. Results from actual robot instruments show that the com-bination works quite well. Meanwhile, this is more thoroughly verifi ed for robot instruments than for many other instruments that are critical to clean. |

Figure 4: Extraction with SDS solution follows on the vortexer

November 2014 edition | www.aseptica.com 21

www.aseptica.com

Up to date, simple, functional: aseptica‘s internet platform offers users access to all the professional articles from our maga-zine.

The website has a pleasant, modern layout. Clear cat-egories make it easy to fi nd information. The Start page gives information about the latest edition of aseptica. The printed version of the magazine can be ordered quickly and simply.

The heart of the the website is the archive, comprising all the editions of aseptica since 1999. An intelligent search function facilitates enquiries. It shows results in chronological order, starting with the most recent entries.

For example, if one searches for the topic "water hy-giene", seven hits are shown. The results lead directly to the relevant articles, fi ltered from the archive. By switching to the English version one can access the archive containing the English editions.

The website also contains additional material to download. The user can directly contact the editorial staff by fi lling in a form.Why not take a look – it’s worth it!

www.aseptica.com |

Figure 1:

A speedy and intelligent

search function aids

research.

Figure 2: Further material concerning aseptica can be

downloaded

Figure 3: The website provides information about

aseptica’s partners

22 November 2014 edition | Create transparent pouches easily yourself

1 Tyvek® is a registered trademark of E.I. du Pont Nemours2 With 6 fi lm rolls, sealing time 1.5 s, 100 mm pouch

length

The fi lling and sealing of pouches and tubes is a particularly safe and reliable packaging system that is an indispens-able part of the preparation of medical products.

Producing pouches yourself from standard reels is a common practice that offers a maximum degree of fl exibility. The in-house production of suitable pouches, however, is gen-erally a manual process and is there-fore associated with considerable time and staffi ng commitments. The user also needs to have the relevant experience to cut the right pouch for the instrument being packaged. The wrong pouch size can increase pro-cess costs.

hawo has developed a solution for this: a fully auto-matic pouchmaking machine known as SealCut (hm 8000 AS-V) for the production of pouches from standard reels.

Create pouches easily yourself

C. Wolf

The machine processes reels compliant with ISO 11607-1both with and without gusseted, as well as Tyvek®1 reels. Cost-effective production

The pouches are produced completely automatically in the desired quantity and length while users are able to focus on more important jobs. Up to six reels of fi lm can be stored on the reel holder. Depending on what is loaded onto the machine, it can then pro-duce up to 5,000 pouches an hour2.

On an optional sorting unit, sorting bays can be po-sitioned into which the SealCut then sorts and ejects the produced pouches.

The required number of pouches in the required length, the complete confi guration and all SealCut settings can be programmed conveniently via the control panel or also using the unique hawo Intel-ligentScan-system. This scanning system allows cus-tom-designed scanning lists to be created via which staff names, materials to be sealed or instrument sizes can be read into the SealCut device. Entire for-mulas can be created as a barcode. With a scan, the machine knows how many pouches of what length at what temperature to produce. With hawo Size-Matic-technology, the user can even confi gure the ideal pouch size with just one scan of the instrument length. The new SizeMatic-technology then calcu-lates the ideal pouch length automatically. The safety distances required as standard are complied with. As a result, the user can produce precisely-dimensioned pouches. Pouches that are too long or too short are therefore fi nally a thing of the past.

Christian Wolf

hawo GmbH

Obere Au 2–4

74847 Obrigheim

Germany

E-Mail: aseptica@hawo.com

Internet: www.hawo.com

| Author

Entire formulas can be created

as a barcode.

Scientifi c Advisors:

H. Biering, DüsseldorfD. Bijl, Beuningen (Netherlands)D. Bremer, HarderbergS. Fuhrmann, ChemnitzA. Hartwig, BerlinH. L. Holz, MainzU. Junghannß, KöthenS. Kauertz, DortmundT. Miorini, GrazM. Pietsch, MainzE. Schott, EssenB. Wilbrandt, Berlin

Published by:

Medienfabrik Gütersloh GmbHCarl-Bertelsmann-Str. 3333311 Gütersloh, GermanyPhone: +49 5241/23480-50Fax: +49 5241/23480-61ISDN: +49 5241/23480-64E-Mail: info@aseptica.comInternet: www.aseptica.com

In cooperation with:Ecolab Deutschland GmbHEcolab-Allee 1 | 40789 Monheim am Rhein;Miele & Cie. KGPostfach | 33325 Gütersloh;OLYMPUS Deutschland GmbHPostfach 10 49 08 | 20034 Hamburg;ebro Electronic GmbH & Co. KGPeringerstraße 10 | 85055 Ingolstadt;Kögel GmbHHagenfeldstraße 4 | 75038 Oberderdingen;hawo GmbHObere Au 2–4 | 74847 Obrigheim

Responsible for contents:Reinhild PortmannPresse- und ÖffentlichkeitsarbeitMiele & Cie. KGCarl-Miele-Straße 2933332 GüterslohPhone: +49 5241/891952Fax: +49 5241/891950

Editors:

Dr. Andreas Otte, EcolabDr. Winfried Michels, Miele Christian Roth, OlympusIven Kruse, ebroPeter Sauer, KögelChristian Wolf, hawo

Translation:Janet Hatfi eld (janethatfi eld1@gmail.com)

Implementing, layout and printing:

Medienfabrik Gütersloh GmbHStephan Dittmar, Ulrich BorghardtTitle topic: Stephen Dalton, © Corbis.

Edition: 2,000

Frequency: Printed quarterlyPrinted on paper processed chlorinefree

Reproduction only with editor‘s permission. Individual contributions may deviate from the opinions of the publishers. No liability is taken for unsolicited manuscripts and photos. The editors reverse the right to shorten reader‘s letters.

ISSN 1439-9016

| Imprint

November 2014 edition | Create transparent pouches easily yourself / Imprint 23

The sorted, produced pouches can be conveniently removed, processed further and labelled. An optional printer will provide a label automatically. All the relevant infor-mation such as the date of production, the expiry date, the batch number, the name of the packer and the name of the medical product can be printed on the label. In seal-only mode, the SealCut can also be used as a heat sealing for closing the fourth side of the pouch.

Validatable process

The SealCut hm 8000 AS-V satisfi es the requirements of ISO 11607-2 and the new ISO/TS 16775 guidance document. In accordance with the standard, the de-vice monitors critical process parameters such as the sealing temperature, contact pressure and sealing time. If any deviations occur, the process is stopped and the user is notifi ed. For routine checks, the machine has a seal check function that can also be activated via the control panel or via the IntelligentScan scanning system. The critical parameters defi ned with validation are displayed following the test seal.

SealCut can also be connected to batch documentation systems using standard RS 232, USB (A/B) and Ethernet interfaces.

Sustainable technology

Its footprint of 740 mm has been achieved thanks to a compact design and even its energy consumption of just 200 Watt has been kept astonishingly low. The use of wear parts has also been reduced to a minimum. (hawo GreenTek). With a power consumption of just 200 Watt, the SealCut uses much less energy than comparable machines.

The new SealCut from hawo once again highlights the company‘s impressive fl air for innovation. hawo, as the innovation leader in the industry, is therefore also one of the top innovators in Germany for the fourth time in a row. This time, it ranked 2nd. Last June, Germany‘s most successful ideas factory once again received the coveted award. "Top 100" Mentor and German TV presenter Ranga Yogeshwar paid tribute to the company at the German SME Summit in Essen. |

German medium-sized

business sector summit:

Hans Wolf (left) and

Christian Wolf (right)

receive one of the

sought-after prizes from

the well-known TV pre-

senter Ranga Yogeshwar.

Product video at

www.hawo.tv

DISCHER Technik GmbHFuhr 4-6 · D - 42781 Haan+49 / 2104 /2336-0 · www.discher.de

Winner of the “Prize for Medium-sized Companies”

MEDICA 2014Nov. 12 - 15, 2014 in Düsseldorf Hall 12, Stand D19

High-tech disinfection for safe hygiene