Introduction
Medical devices decontamination services for re-processing re-usable invasive medical devices used by several hospitals is a very important undertaking in view of the critical role that these medical devices play in the lives of human beings (ISO 14971:2000). Consistency of contamination control within the clean room is therefore of utmost importance. This can only be achieved through well structured and properly executed monitoring programmes (EN ISO 14644-2:2000), which would ensure that clean rooms are kept free from all kinds of contaminants (CEN ISO/TR 14969: 2005).
Acme Medical Limited deals in the provision of decontamination services for re-processing re-usable invasive medical devices used in several hospitals. The objectives of the report under review were to validate the methods to be used for monitoring environmental bio-contamination throughout the decontamination process and to determine appropriate warning and action limits.
This critique therefore reviews the procedure and materials used for monitoring environmental bio-conamination throughout the decontamination process and seeks to find out if the result obtained can be used to determine appropriate warning and action limits. It was commendable to note from the validation report that all processed products were terminally sterilized using a porous load steam sterilization process which was compliant with international standards BS EN 554 and BS EN 285. This critique also includes: an indepth review of the validation report, identification and reporting of any perceived deficiencies in the materials and methods, making recommendations for necessary corrective measures to be incorporated and determining whether the data reported would demonstrate the consistency of bio-contamination control within the facility.
Details and Analysis of the Methods used for monitoring environmental bio-contamination throughout the decontamination process
The objectives, materials and methods used in monitoring bio-contamination within the facility were highlighted in the validation report including the sampling schedule, exact times of operation and environmental cleaning. However, it was not clear from the report whether the methods and materials used were in compliance with the published EN ISO 14644-2:2000 or not. In addition it was reported that sampling was carried out during normal operations; with all the rooms occupied and all automatic equipment in the facility working. This was particularly important as it was the most likely method by which the best indicative samples reflective of the actual situation on the ground could be obtained.
It is commendable to note from the validation report that control of microbial contamination was maintained through various methods such as: differential pressure ventilation with filtered air, controlled access for people and materials, appropriate personal behaviour, appropriate protective clothing and controlled environmental cleaning. However, the report did not state their compliance to international standards nor did it state whether the instruments used in the validation were regularly calibrated as required by international standards EN ISO 14644-2:2000.
The number and position of sampling points within the facility were determined as required by international standards; BS EN ISO 14698-1:2003 and BS EN ISO 14644 for Class 7 clean room. The procedure used in swabing the surfaces and recovery of the organisms from the swabs were also given; and this was commendable.
In the validation report it was stated that airborne contamination was sampled using settle plates (S1 to S9), however, the procedure used and the standards against which they were measured was not given; and was therefore not in conformance to BS EN ISO:14644-2:2000. It is however commendable to note that the incubation conditions for Malt Extract Agar (MEA) and Tryptone Soya Agar (TSA) were given, though it was not clear whether they were in conformance with ISO 14644 or not.
It was also comendable to note that the site layout and all sampling points were clearly outlined in the validation report with exact positions of air inlets and extract vents shown. In addition, sampling plan for fluid samples were also given, outlining the points from which water samples were obtained. Likewise, locations of settle plates used for air sampling and working surfaces from which swabs were collected were also outlined clealy in the layout and the codes used explained clearly as provided for in BS EN ISO 14644-4. The layout of the facility therefore clealry showed the way different areas were designed, arranged and sampled. It is commendable to note that various areas within the layout and the fittings such as sinks, work stations etc were clearly labelled.
In addition, there was a controlled supply of air through strategically placed air inlets and extract vents to various within the facility, however it was also not clear whether air flow tests were done as required in BS EN ISO 14644-3.
In sample collection, it was unclear whether or not the sampling methods used were in accordance with the relevant documented procedures. The swabs used for sample collection on working surfaces and settle plates suitable for qualitative and quantitative evaluation of possible surface contamination by airborne particles were acceptable as they conformed with to the internationally acceptable standards (IEST-RP-CC004.2:1992). Steps on water sample tests; which should have been given were however not given. In addition, Gram staining, pigmentation and coagulase tests used as bases for which determination of negative Staphylococci and other bacteria in microbial identification should have been given in accordance to the internationaly set standards (BS EN ISO 14644).
The frequency of sampling, date of validation and the frequency of the validation were all provided as required by international standards BS EN ISO 14698-1:2003. In the sampling procedure, devices used in air borne contamination determination, though simple were highly reliable. However, it was not clear weather they were certified by international standards as required by BS EN ISO 14698-1:2003.
Following the BS EN ISO 14698-1:2003, there should have been a “Hazard Analysis Critical Control Point (HACCP)” system within the facility to assess and control the risk factors that may affect the microbiological quality of the clean rooms. Such a system should be set to address the following: Identify potential hazards, assess the likelihood of occurence of these hazards and identify measures for their prevention. Designation of risk zones for this facility was clearly missing (Pierson & Corlett, 1992).
It was not clear in the validation report whether this facility (Acme Medical Ltd) strictly adhered to the set microbiological alert and action levels as required by BS EN ISO 14698-1:2003. However, it was comendable to note that the establishment had some arbitrary control limits that were used as alternatives to microbiological alert and action levels. From the validation report, it was also clear that the facility lacked a set of corrective actions to be taken when monitoring results as required in BS EN ISO 14698-1:2003.
In addition, it was not clear weather or not the establishment had a documented sampling plan as required by international standards (BS EN ISO 14698-1:2003).
In the conclusion section of each of the four validation reports, it was stated that there were no changes required in the monitoring method or frequency yet the results of fungal counts in fluid samples in some validation reports (2) were more than the amount proposed to warrant an action, yet no action plan was proposed. The action plan to be taken in case any corrective measures were to be taken was also not given contrary to BS EN ISO 14698-1:2003.
It is also not mentioned in the validation report whether or not the staff were given training in accordance with the standards published in BS EN ISO 14644-5:2004. Clean room clothing (VCCN-RL-6.2:1996) (such as make up, jewellery) for the staff and the visitors was also not clearly stated or documented. However, it was comendable to note that wash rooms and staff gown rooms were set aside probably for use by members of staff.
Compliance with Published BS EN ISO 14698, BS EN ISO 14644 and BS EN ISO 13485 Standards
Assessment and control of risk factors as per BS EN ISO 14644-5 requirements were clearly missing in the report. However the premise had some arbitrary control limits as recommended by international standards which they used in place of HACCP.
The report also showed that the establishment had a documented sampling plan as required under international standards BS EN ISO 14698-1, while detection of microbial contamination was done in accordance to standards published in ISO 13485. All in all, Acme Medical Ltd company which provides medical device decontamination services for re-processing re-usable invasive medical devices used by several hospitals met most of the required international standards, though it must be emphasized that it should meet all the international standards of hygiene (Whyte, 2001).
Consideration of Whether the Data Reported Would Justify validation of the methods to be used for monitoring environmental bio-contamination throughout the decontamination process
It was comendable to note that the results of the validation excercise were given in tabular format and explained further in the calculation section; making then easy to interpret and understand. However, under identification and reporting section in the validation report, it was stated that bacterial growth were examined visually and colonial morphology reported. This method may not have been completely accurate since chances of missing some microscopic bacteria were relatively high, necessitating the use of other equipments such as microscopes as was the case for fungal growth examination.
The data reported for the bacterial and fungal counts for the fluid samples, air samples and surface samples of the facility may justify the validation of the methods used for monitoring environmental bio-contamination through out the decontamination process since the results for all the four reports carried out using the same procedure and settings but at different times were generally consistent. For instance, most bacterial counts for the fluid samples, air samples and surface samples were below the limits required for issuing a warning; with only a few instances having slightly higher counts that waranted some action. On the other hand, fungal counts for fluid samples were similar for all the four validation reports (i.e. zero) except for isolated instances in the wash room wash sink that had 1 and 2 fungal cfu/100ml for validation reports number; ACME-TR-ENV-0506-01 and ACME-TR-ENV-0806-01 respectively.However, the conclusions made in the two reports(ACME-TR-ENV-0506-01 and ACME-TR-ENV-0806-01) just like those made for reports without any fungal counts in fluid samples were the same (i.e. no change required in monitoring methods or frequency). This shows that the proposed control limits were not followed keenly as required.
References
BS EN ISO 14644-1.(1999). Clean rooms and associated controlled environments.Part 1: Classification of air cleanliness
BS EN ISO 14644-2. (2000) Clean rooms and associated controlled environments Part 2: Specifications for testing and monitoring to prove continued compliance with ISO 14644-1.
BS EN ISO 14644-4. (2001). Clean rooms and associated controlled environments Part 4: Design, Construction and Start-up.
BS EN ISO 14644-5. (2004) Clean rooms and associated controlled environments Part 5: Operations.
BS EN ISO 14644-3. (2005) Clean rooms and associated controlled environments Part 3: Test Methods.
BS EN ISO 14698-1. (2003) Clean rooms and associated controlled environments. Part 1 Biocontamination control. General principles and Methods.
CEN ISO/TR 14969. (2005) Medical devices-Quality management systems- Guidance on the application of ISO 13485:2003.
IEST-RP-CC004.2. (1992) Evaluating wiping materials used in cleanrooms and other controlled environments. Rolling Meadows, Illinois: Institute of Environmental Sciences and Technology.
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