Operating Manual WD 425E
Rev. 1.
1
, LS Page 7 of 34
78563_E rev 1.1.doc
1. General Directives ref. Medical Products Processing
1.1 Pre-treatment of Medical Product
Basically, all outer and inner surfaces to be treated must be accessible for the decontamination, disinfection
and sterilization liquids (open valves / faucets, linkage instruments!). Special attention is required for the lu-
mens. Complex medical products may require disassembly. Prior to processing, MIC instruments must be
disassembled according to manufacturers’ instructions. Baked on remnants are extremely critical for instru-
ments used in operative endoscopies, as removal of grime remnants found in narrow lumens are hard to
remove by machine mechanical processes. Advice by manufacturers of medical devices must be heeded
(DIN EN ISO 17664, requirements information to be made available by the manufacturer referring to the for-
mation of medical products, designed for sterilization).
Course soiling of any medical product must be removed immediately upon application. Remaining of dried
blood and tissue must be prevented by establishing suitable procedures (e.g. wiping of external soiling and
rinsing of channels immediately upon application). This is required especially for the optimal prevention of
performance curtailment (drying of viruses in protective colloids).
Ways and means of pre-cleaning must be adapted for the subsequent reconditioning processes and must
not impede them (fixation of blood and proteins, foam formation in the CDM).
Impediment of decontamination is given by:
•
Pretreatment with aldehyde disinfection media
•
Pretreatment with alcoholic solutions
•
Dropping antiseptic solutions on wash goods
•
Aldehyde and alcohol vapors
•
Heat pretreatment
!All such treatments act in the sense of fixing proteins and may e.g. contribute to the conservation of prion in-
fectiousness !
See recommendations by the RKI „Requirements for hygiene in processing medical products. Federal Health
Flyer 44 (2001) : 1115-1126”
1.2 Notes ref. orderly Cleaning
1.2.1
Influence of time and temperature
In the selection of process and program parameters such as temperature, time and additives, keep the fol-
lowing in mind:
Chemistry and mechanics need
time
to develop their effectiveness. One should never be skimpy with regard
to time used in cleaning.
Initial high temperatures at the beginning of a cleaning process may fix proteins. It is for that reasons that a
cleaning process should always start with a generous, cold pre-rinsing cycle. Cold pre-rinsing should not be
too short, in order to prevent any denaturing of proteins. After all, freedom from proteins also means ab-
sence of prions.
Alkaline cleaning is characterized by high efficiency pertaining to dissolution of protein and fat remnants. On
the other hand, it may have the disadvantage of altering materials. Under this aspect, it may pay off to select
medical products that can tolerate alkaline cleaning.
For alkaline cleaning, this rule of thumb applies: augmentation of cleaning temperature by 10 °C results in
doubling the cleaning performance. In fact, alkaline detergents are capable of developing their protein-