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by Jalel Ben Mesmia | University Hospital Schleswig-Holstein, Kiel, Germany | contact via mail
Overall process validation of the reprocessing of semi-critical ultrasound probes – is it also a solution for the validation of the reprocessing of critical gamma probes? In various medical specialties, ultrasound probes are used for diagnostic purposes, gamma probes are used intraoperatively. With regard to the type of use and the resulting risk, ultrasound probes are usually classified by the operator as semi-critical, gamma probes as critical medical devices (according to the KRINKO recommendation from 2012).
For lack of alternative reprocessing processes, in common practice ultrasound probes are often reprocessed manually with a final wipe disinfection with ready-to-use wipes.
In 2016, the German Society for Hospital Hygiene (DGKH) published "Notes for the reprocessing of selected semi-critical medical devices" with the following statements:
- If several options for reprocessing are given, the safest method is to be used. This is generally the automated process in a washer-disinfector, if possible.
- A validated process must be established by the operator for both an automated and a manual reprocessing process.
The validation of manual wipe disinfection processes has proven to be very time-consuming and difficult, so alternative processes are increasingly being considered by operators. Automated and validatable high-level disinfection processes, such as e.g. Trophon (Nanosonics), represent practicable alternatives for a validatable automated disinfection process.
On 20 November 2020, the Robert Koch Institute answered a question regarding the validability of the final disinfection of semi-critical medical devices using wipes as follows (excerpt):
- A validability of the final wipe disinfection of semi-critical medical devices is currently ... not given.
- The RKI is not aware of any guideline or standard that could serve as an adequate basis for ensuring this requirement.
- According to German law, on-site validation is required as part of the mandatory validation requirements for reprocessing semi-critical medical devices.
The criticism based on the non-validation of the final wipe disinfection is in line with the German Medical Devices Operator Ordinance (MPBetrV) and the KRINKO/BfArM recommendation. In the “Guideline for the validation of manual cleaning and manual chemical disinfection of medical devices”, a wipe disinfection process is not taken into account either. Thus, the automated disinfection process comes to the fore and currently offers itself as the only validatable process.
However, limiting validation to the automated disinfection process is not sufficient to describe the entire reprocessing process (cleaning and disinfection) as validated. The reprocessing process consists of the following subprocesses:
Semi-critical medical device
- Cleaning (manual
- Disinfection (automated)
Critical medical device
- Cleaning (manual
- Disinfection (automate)
- Sterilization (automated)
In order to achieve an overall process validation, all sub-processes must be considered and validated according to the respective guidelines or standards, even if this is to be carried out in different phases and the result consists of different validation reports.
First validation phase sub-process " manual cleaning"
According to the "Guideline for the validation of manual cleaning and manual chemical disinfection of medical devices".
- DIN EN ISO 14971
- DIN EN 14885
- DIN EN ISO 17664
Second validation phase sub-process "automated disinfection"
According to the "Guideline of DGKH, DGSV and AKI for the validation and routine monitoring of automated cleaning and thermal disinfection processes for medical devices".
- DIN EN ISO 15883
- DIN EN 14885
- DIN EN ISO 17664
If gamma probes classified as critical are approved for the Trophon process and the appropriate, validated sterilization process approved by the manufacturer is available for this purpose, a third validation phase sub-process "automated sterilization" will follow:
- e.g. DIN EN ISO 14937 (plasma sterilization)
This represents the overall process validation according to the German Medical Devices Operator Ordinance (MPBetrV) §8 Para. 1 in the context of the reprocessing of semi-critical ultrasound probes and also offers a solution for the validation of the reprocessing of critical gamma probes.
++ Published in the ZENTRALSTERILISATION abstract journal for the DGSV congress 2021 ++
