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Recommendations by the Quality Task Group
[11] Programmes for Automated Processing

Washer-disinfectors can be operated with three different programmes, with provision made for changing the programme controls during the various steps to suit the respective requirements. In addition, the washer-disinfector may have several permanently set programmes. The following article gives an only general overview of the RKI programme, the Vario programme and of a programme with a chemical disinfection step for heat-sensitive items1.

RKI or Epidemic Programme
Years ago there was in Germany only one programme with a thermal disinfection step. This programme is known today as the BGA (former German Federal Health Office), RKI (Robert Koch Institute) or EPIDEMIC PROGRAMME. This programme owned its existence primarily to the views of the Federal Health Office, or of the managing directors Prof. Spicher and Prof. Peters, which aimed at maximum safety for personnel and environment.

Accordingly, in this programme (fig.1) already the first flowing water or the detergent solution must be disinfected. Pre-cleaning without disinfection is therefore not possible. CLEANING, is carried out together with thermal disinfection in a first programme step. The detergent is added after inflow of the water. Heating and simultaneous cleaning take place during circulation. Until a temperature of approx. 70 °C is reached, residues must be removed from the instruments by rinsing, emulsification, dispersion and disintegration and these must be in as stable a solution as possible, so that they are not deposited again on the instruments during the ensuing circulation and drainage of the detergent solution. If the heating and cleaning phase to 70 °C is executed too quickly, residues remain which can later coagulate in or on the instruments and become insoluble. Some instruments may then not be clean.

Fig. 1: RKI- or epidemic programme

In such cases, a hold time can be programmed at optimal cleaning temperatures. Since alkaline or alkaline-active-chlorine-based DETERGENTS are used in this programme, a hold time would be recommendable after reaching a temperature of 60 °C. To what extent neutral or low alkaline detergents are suited to the RKI programme must be inferred from the manufacturer’s recommendations. It is important that quick and widespread detachment of all residues take place when using combined cleaning and disinfection.

For thermal disinfection, the detergent solution is heated to 93 °C. This TEMPERATURE is maintained for 10 minutes based on the recommendations of the RKI, thus assuring bactericidal, fungicidal, tuberculocidal and virus-inactivating action, including hepatitis B viruses (HBV). Extremely high safety has been incorporated for inactivation of HBV, since not all CSSD staff members will have been vaccinated against HBV.

The solution is drained after the combined cleaning and disinfection step. To neutralise the residues of the alkaline detergent solution, which are generally in the range of pH 11 to pH 12.5, and thus enhance rinsing, a NEUTRALISING AGENT, based on phosphoric acid or organic acids is added to the first rinse water. At least two further rinse cycles follow. The last rinse water, also called final rinse, should be carried out with demineralised water to prevent formation of stains on the instruments and, if the drinking water contains large quantities of table salt, to prevent chloride-induced pitting corrosion due to chloride deposits on the steel instruments after drying. The FINAL RINSE water is heated to a temperature of > 75 °C to kill any microorganisms present, e.g. Pseudomonas aeruginosa and facilitate subsequent drying.

Already in the 80s, the call for disinfection of the first flowing solution was restricted to the occurrence of pathogens with epidemic potential. The MEDICAL OFFICER can decree that under certain circumstances only the RKI or epidemic programme be operated. This means that the washer-disinfector must be able to execute this programme.

¹ This paper gives an overview of the RKI or epidemic programme. The Vario programme as well as a programme with a chemical disinfection step for heat-sensitive items will be described in the next edition.