No.

That depends on the heat treatment during the hardening process. The hardness of high-quality instruments is the same throughout.

Established cleaning, disinfection and sterilisation processes do not have any negative effect on the original usage properties of stainless steel instruments. This also applies, for example, to wear on cutting surgical and microsurgical instruments. As a result, the steam sterilisation process, which has been discussed repeatedly in this context, should be given preference over other sterilisation methods as it is most effective from a hygienic point of view.

Investigations on the cleaning of instruments or stainless steel test challenge devices with the design features of instruments have focused mainly on joints, not knurled handles.

Laser labelling is a procedure used for identifying medical instruments. As with etching, the conventional method of marking and identifying instruments, laser labelling must also be clearly visible and resistant to standard conditions of use and reprocessing. Provided correct procedures are used for laser labelling, the graphics will be degraded. Corrosion of laser labelling is usually due to insufficient guidelines or faulty procedures in the labelling process. We are not aware of any literature on this issue. At this point, however, we would also like to point out that any factor triggering or promoting corrosion such as contact with water containing high amounts of minerals or salts should be avoided during reprocessing.

It is correct that the assessment of disinfectants result in combination of concentration/exposure times. In the case of instrument disinfection according to the test method issued by the German Society for Hygiene and Microbiology (DGHM), the exposure times tested are 15 mins., 30 mins. and 1 hour. Longer exposure times, where the test method would lead to more dilute concentrations, are not tested. The reason for this is that dilute concentrations promote the resistance of microorganisms and, in addition, the risk of corrosion is increased because the concentration of corrosion inhibitors in the solution is too low.

Practical experience shows that soiled instruments can be stored untreated for up to 6 hours after use without influencing cleaning performance in the machine. If stored overnight or over the weekend, adequate cleaning cannot be guaranteed. In addition, there is a risk of corrosion due to blood or physiological salts adhering to instruments over a prolonged period. If soiled instruments are stored overnight or over the weekend, corrosion must be expected.

As far as we know, manufacturers use different materials for reusable needles. A rough distinction is made between needles made from corrosion-resistant high-alloy steel and needles made from electroplated low-alloy (i.e. non-corrosion resistant) steel. In principle, both types can be reprocessed in washer-disinfectors/sterilisers using programmes certified for surgical instruments made from stainless steel. pH-neutral or mildly alkaline reprocessing is particularly suitable for chrome-plated needles and other chrome-plated instruments. The needles must be held in suitable containers during reprocessing so they are not lost in the washer-disinfector or steriliser chamber. Needle boxes provided by manufacturers are particularly suitable for this purpose and they also ensure adequate cleaning. As well as checking whether the instruments have been cleaned sufficiently, chrome-plated/nickel-plated needles in particular require thorough checking for surface damage. This is best done using a magnifying glass. If the needle is chrome-plated or nickel-plated, the chrome or nickel forms a protective coating on the substrate designed mainly to make the instrument corrosion-resistant. This layer, however, will always contain micro-fissures. Extended cracks will form over time as a result of mechanical strain. Such parts with prior damage are exposed to additional attack during reprocessing because of chemical ingress and a reaction which induces corrosion. Needles damaged in this way must be taken out of circulation and discarded in order to protect other instruments. There is a risk of transfer to other uncorroded instruments (secondary corrosion). The number of reprocessing cycles is therefore determined by surface integrity. Needle boxes can be used for cleaning, sterilisation and storage of needles at the point of use. During routine use, rubber-coated magnetic plates have proved effective for passing needles to the surgeon at the point of use. After cleaning in a washer-disinfector, the needles are arranged on these plates when instrument sets are reassembled.

Products from well-known instrument manufacturers do not show any difference in corrosion resistance. This is assured by appropriate welding methods, welding parameters, and, where applicable, by the use of additives and subsequent heat treatment to improve the homogenisation of the material.

In our opinion, a bedpan washer is not suitable for reprocessing surgical instruments as the processes on these devices are not designed for this purpose. This applies to cleaning performance, rinse quality as well as thermal disinfection parameters. In the case of the latter, HBV effectiveness may also have to be ensured. Keywords: Treatment in bedpan washers

Indeed, the anodised layer on aluminium instruments may suffer under these conditions. However, it should be noted that there are hardly any aluminium instruments or instrument components made from aluminium. Furthermore, there are chemical suppliers who sell alkaline detergents offering 100% material compatibility even at the pH values specified, at least for products which are not colour anodised. In this context, however, the water quality, especially in the last rinse water used for thermal disinfection, must also be taken into account. Whereas softened water can severely damage anodised coatings, fully demineralised water protects anodised coatings by making them denser.

To date, we are not aware of a single case in which dissolution products from aluminium instruments have resulted in an increase in the susceptibility of stainless-steel instruments to corrosion. In addition, if sufficient final rinsing is carried out in the washer-disinfector, all dissolved aluminium corrosion products are rinsed off stainless steel instrument surfaces.

The chemical passivation of stainless steel is carried out industrially preferably with citric acid, but also with nitric acid. In use, all acidic process chemicals, such as citric or phosphoric acid used as neutralising agents, have a passivating effect.

With intensive use according to the intended purpose and reprocessing according to the current state of technology, a cutting life of about 6 months can be expected for high-quality products. With normal wear and tear, the cutting properties gradually decrease. In the event of a sudden loss in performance, it may be concluded that the above criteria have not been applied either individually or in total. In this case, we recommend that the affected product be sent to a qualified repair service or to the manufacturer for repair.

Steam sterilisation is usually performed with saturated steam at 134°C. For items with limited thermal resistance, a temperature of 121°C can be used for a correspondingly longer period of time. Sterilisation must be carried out using a procedure that conforms to standards and is suitable for the items to be sterilised. The packaging of the items to be sterilised must also meet the applicable standards with regard to the quality and use of the packaging materials and must also be suitable for the sterilisation process selected.

Pitting means that the passive layer on instruments is degraded by halides, especially chlorides (e.g. in physiological saline solutions). The risk of chloride-induced pitting increases with increasing chloride concentrations due to drying and prolonged exposure. Placing the instruments in physiological saline solution to allow residues to dry therefore leads to pitting. Wiping of instruments with a soaked compress can be tolerated according to previous experience. At least high-quality instruments must be able to withstand this treatment!

Proper cleaning and disinfection according to the manufacturer's instructions is sufficient. Further information on this topic can be found in the current issue of the Red Brochure in Section 4 "Recommended action for returned goods / returns". Repair staff is not endangered by non-sterile instruments.

In the case described here, the prior disinfection of instruments is the reason why reprocessing in a washer-disinfector has no effect. When exposed to chemical disinfectants, blood residues can bond and adher to surfaces like a varnish coating. For this reason, the Red Brochure published by the AKI recommends the dry disposal of instruments and immediate transfer to a washer-disinfector.

The decision whether or not to sterilise mouth mirrors in your hospital/department is ultimately subject to internal hygiene regulations. Hygiene guidelines (see www.rki.de) stipulate that non-invasive instruments and instruments which do not come into contact with wounds do not need to be sterile when used. At the same time, however, it is pointed out that special hygienic requirements may apply to dental surgical procedures. Mouth mirrors can be steam-sterilised from a material point of view. However, these are consumables which become blind due to moisture ingress (due to different thermal expansion coefficients). The same applies to mechanical reprocessing / thermal disinfection.

Aluminium instruments are suitable for ultrasonic cleaning, provided the instrument manufacturer's approval for ultrasonic cleaning has been obtained. The detergents or disinfectants used for this purpose should be recommended by the chemical manufacturer for aluminium.

No. Steam and the temperatures prevailing during steam sterilisation (up to 143°C) are completely uncritical with respect to the performance characteristics of instruments, regardless of the duration of the holding time. This means that neither the hardness nor the metal structure is changed by steam sterilisation. Consequently, the cutting and wear properties do not suffer either. It should also be noted that, as in the present case, thermally resistant medical devices should preferably be steam sterilised from a hygienic point of view.

Proven cleaning, disinfection and sterilisation methods have no detrimental impact on the initial usage properties of stainless steel instruments. This also applies to the wear and tear on surgical and microsurgical cutting instruments. Hence, steam sterilisation is the method of choice. From a hygienic point of view, steam sterilisation is the most effective method available.

This refers to the debate concerning manual reprocessing and machine reprocessing of instruments for eye operations. In principle, the method of choice should be reprocessing in washer-disinfectors/sterilisers. In many recommendations, leaflets and brochures, thermal disinfection methods are advocated as being superior to chemo-thermal or chemical methods. Machine washing and disinfection in a closed system also serves a key function by protecting members of staff. Another factor is that only machine processes can be reproduced in a sufficiently precise and validated manner that meets the requirements of the operator's regulations. The concerns of doctors and nurses relating to the sensitivity of instruments are no longer justified. Particularly in the case of instruments used in eye operations, baskets and perforated trays with holders ensure secure storage. Rinsing nozzles and the alignment of the rack for holding baskets and perforated trays must be such that instruments are not released from their holders. This would be the case if standard rinsing technology for surgical instruments were used. Provided rinsing procedures and rinsing technology are used correctly, machine cleaning is gentler than manual cleaning. Aseptica 7 (3); 2001: 18-19 reports on a practical example of the reprocessing of microsurgical instruments.

No, active pitting can cause extraneous corrosion deposited on other items. Depending on the cause, severity and extent of pitting, affected instruments concerned should be removed from the reprocessing cycle. Such instruments should be returned to the manufacturer or a qualified repair service for reconditioning. For further information, cf. the Red Brochure, 8th Edition, Pages 55-56.

Ideally, cleaning performance is such that all residues including the care products are removed during the cleaning process. All instruments with metal sliding surfaces should therefore be lubricated after each cleaning process as recommended by the manufacturer.

The use of an instrument eraser is not recommended because this may result in material removal and damage to the surface of the instrument.

In principle, acidic basic cleaning is recommended for instruments with freely accessible surfaces.

Instruments with hard-to-reach areas should be sent to the manufacturer for repair.

There is no ban on using these materials in surgical instruments. However, they have been replaced by other materials at many manufacturers because the service life is sometimes unsatisfactory, especially under alkaline reprocessing.

Like all instruments, these handles must be checked for integrity after the reprocessing process.

In steam sterilization, gaps such as those in closed scissors or clamps are not a challenge for steam penetration.

What is important is the opening of gaps, such as in the case of scissors, for cleaning in the washer-disinfector. Validated processes ensure that the medical devices can then be steam sterilized as intended.

There are no specific guidelines in Germany on the question you have asked.

Instruments used in pathology should be cleaned and disinfected separately from medical devices used on patients.

Conducting a risk analysis and assessment together with the responsible hygiene department is recommended.

One solution may therefore be to reprocess instruments from pathology in a separate washer-disinfector.

Cannulae with a diameter of less than 1 mm are difficult to reprocess. Cannulae with a diameter of less than 0.5 mm should not be reprocessed as perfect cleaning cannot be assured. However, the possibility to reprocess a cannula does not only depend on the diameter; its length is also important. To assure the safe processing of such narrow-lumened instruments, the following aspects must be taken into account: Lumens must be rinsed with sterile water immediately after use to prevent any blockage. If possible, use a non physiological salt solution. Check with a suitable guide wire that a lumen is not obstructed. Make sure that the interior is thoroughly dried after reprocessing; if necessary blow through it with a dry syringe until no more moisture emerges. Steam sterilise using a fractioned pre-vacuum according to EN285. Manufacturers have proved in a sterilisation study (Part 1 published in Zentralsterilisation 2001; 9(6) 425 - 437 and Part 2 published in Zentralsterilisation 2002; 10 (2) 100 - 109) that lumens with an inner diameter of 0.5 mm and a length of 500 mm can be sterilised with a fractioned pre-vacuum according to EN285.