Washer-disinfectors:
For cleaning and disinfection.

An often overlooked but crucial factor for the operation of a washer-disinfector is the quality of the water used. The choice of water quality has a direct influence on the performance and longevity of the device as well as on the hygiene of the processed instruments.

Operating a washer-disinfector with tap water

In principle, a washer-disinfector can be operated with ordinary tap water. Tap water is readily available and meets the basic requirements for operating such devices in most regions. However, it is important to be aware of the potential disadvantages of using tap water:

• Scaling: tap water usually contains minerals such as calcium and magnesium, which can build up inside the appliance as well as the instruments over time. This calcification can impair the efficiency of the washer-disinfector and lead to increased maintenance requirements.
  

• Water stains: Mineral residues in tap water can leave water stains on the cleaned instruments. These stains are not only aesthetically unpleasant, but can also impair the surfaces of the instruments and their functionality.

Advantages of using demineralized water

To avoid the disadvantages mentioned above and to maximize the service life and efficiency of the washer-disinfector, we recommend connecting it to a water treatment system, such as MELADem 53, to use demineralized water for the final rinse. Demineralized water, also known as demineralized or deionized water, is water from which almost all minerals have been removed.

To ensure that the important process of automated cleaning and disinfection runs smoothly and effectively, it is crucial to regularly maintain and validate a washer-disinfector. But how often should this be done?

Regular maintenance: a must for smooth operation

The maintenance of a washer-disinfector includes various inspections and servicing work to ensure that the appliance is always working in optimum condition. The frequency of maintenance may vary depending on the manufacturer's specifications, frequency of use and the specific requirements of the facility in question.

The maintenance cycle of MELAtherm 10 / MELAtherm 10 Evolution is either 1,000 cycles or 24 months - whichever occurs first in the practice or clinic.

Validation: Ensuring disinfection quality

Validation of a washer-disinfector is a process that ensures that the device complies with the prescribed hygiene standards and cleans and disinfects effectively. This is particularly important in medical facilities, as inadequate cleaning and disinfection can have serious consequences for patient safety.

According to current requirements, a thermal disinfector such as the MELAtherm 10 should be validated after just 12 months. However, there is also a standard that allows this interval to be extended under certain conditions.

• Initial validation: When commissioning a new washer disinfector, an initial validation should be carried out to confirm that the device is correctly installed and working properly in your practice.
  

• Regular revalidation: After the initial validation, regular revalidations should be carried out. A common period for this is annually, as prescribed by current requirements. However, the DIN SPEC 58929 standard states that, under certain conditions, validation after a risk assessment is also possible at an interval of 24 months. However, this extended validation interval must be recognized by regional authorities and by the validator after a risk assessment.
  

• After repairs or modifications: After major repairs or modifications to the appliance, a new validation should be carried out to ensure that the cleaning and disinfection performance has not been impaired.

Maintaining the highest standards of hygiene is essential in modern medical practices and clinics. Washer-disinfectors (WDs), also known as washer-disinfectors, play a crucial role in this. These devices are specially designed to ensure effective and reliable cleaning and disinfection of medical instruments and utensils. It utilises a combination of mechanical, chemical and thermal processes to achieve a high level of germ reduction and safely prepare the instruments for reuse. The process in a washer-disinfector typically comprises several key steps:

1. Pre-rinsing: This first step in the process of cleaning and disinfection using a washer-disinfector is crucial as it removes coarse impurities such as blood and other biological materials from the instruments. This facilitates the effectiveness of the subsequent cleaning phases by effectively rinsing proteins from the instruments with the cold water pre-rinse.

2. Main cleaning: In this phase of the thermal disinfector, special detergents formulated for medical applications are added that are designed to effectively dissolve organic and inorganic materials from the instruments. These alkaline detergents work by chemical processes that denature proteins and emulsify fats, allowing even stubborn soiling to be removed.

3. Intermediate rinsing: After the instruments have been thoroughly cleaned, it is crucial to thoroughly remove all residues of the cleaning agents. This is done in the rinse cycle, where clear water is used to eliminate any residue. Thorough rinsing is necessary to ensure that no chemical substances remain that could compromise sterility or cause reactions on subsequent contact with patients. This step ensures that the instruments are absolutely clean and free of potentially harmful residues.

4. Disinfection: This step is central to ensuring that the instruments are disinfected. High temperatures, often between 90°C and 93°C, are used to achieve almost complete destruction of all microorganisms. The heat acts quickly and effectively against bacteria, viruses and fungi as well as more robust spores that can pose a threat to health. The use of high temperatures in this process step ensures that the semi-critical instruments are not only clean, but also hygienically safe for the next use.

5. Drying: The final step in the washer-disinfector / washer-disinfector process is drying the instruments. Any moisture remaining after disinfection could provide an environment in which microorganisms could thrive. Therefore, it is important that the instruments are completely dried before they are stored or reused. Drying helps to prevent the formation of rust on metal instruments and ensures that the instruments are in optimal condition to maintain their longevity and functionality.

The integration of washer-disinfectors into the operating procedures of medical facilities offers many advantages for clinics, medical and dental practices:

• Standardisation of cleaning processes: Washer-disinfector ensure consistent cleaning and disinfection cycles, which improves the reliability of results and supports compliance with hygiene standards.

• Increased efficiency: Automating the cleaning process allows medical staff to focus more on direct patient care.

• Minimising the risk of infection: By effectively eliminating germs, the risk of infection and cross-contamination is significantly reduced.

• Protection of staff: Automated systems reduce the need for direct contact with potentially infectious materials, minimising the risk to staff.

Careful selection of a thermal washer-disinfector (WD) or washer-disinfector is essential to meet the specific requirements of your medical facility. The following aspects should be taken into account:

• Capacity and throughput: The size and throughput of the washer disinfector should be matched to the volume and type of instruments regularly used in your facility. A device that is too large may consume energy unnecessarily, while one that is too small could cause bottlenecks.

• Reliability and ease of maintenance: Choose devices from established manufacturers known for their durability and ease of maintenance. A widely trained service network minimises downtime and facilitates regular inspections and repairs at moderate service prices.

• Energy and water efficiency: Modern thermal disinfectors offer with practice-optimised wash chambers and advanced energy and water saving technologies that not only reduce operating costs but are also environmentally friendly.

• User-friendliness and ergonomics: An intuitive control panel, ergonomic design features and easy accessibility for maintenance increase user-friendliness and support quick familiarisation of new employees.

• Compatibility and versatility: Ensure that the washer-disinfector and corresponding adapters are compatible with different types of medical instruments and offers specific programmes for different cleaning requirements.

• Integrated documentation capabilities: Some advanced models offer built-in logging and approval features that automatically document each cleaning and disinfection cycle, making it easier to comply with regulatory requirements.

• Service and support: Good customer service and technical support are essential. Check the availability of local service and spare parts to ensure the appliance is always ready for use.

• Drying: Integrated drying at no extra cost prevents recontamination after reprocessing and protects your high-quality instruments from potential corrosion.

Investing in a high-quality washer-disinfector is therefore a wise decision that will contribute to the quality of patient care, compliance with health standards and the efficiency of clinical operations in the long term. For medical facilities striving to maintain excellent hygiene practices, choosing the right washer-disinfector based on capacity, reliability, ease of use and technological features is crucial.

In conclusion, the role of a thermal washer-disinfector in modern medicine should not be underestimated, as they are fundamental building blocks for safe medical practice and play a key role in preventing infections and ensuring patient safety.