The Effectiveness of a Standardized Sampling Program To Maintain Water Quality of Endoscopic Washer/Disinfectors at the Vale of Leven District General Hospital, NHS Argyll & Clyde, Scotland, United Kingdom

ISSUE: The Scottish Health Technical Memorandum (HTM20:30) requires regular water sampling of washer/disinfectors as an indicator of any gross failure of the processing equipment. Sampling of the Endoscopic Washer/Disinfectors (WDs) was commenced in August 2003 at the Vale of Leven Hospital. The WD in theatre was consistently positive for CFU (colony-forming units) including Pseudomonas species in the sampling port tap and the bath water. Despite weekly sampling, the source could not be determined. Results from the water testing ranged from 50 to >10.000 CFU, causing procedures to be suspended while the machine and filter system was manually disinfected. PROJECT: A local working party was organized to determine the cause of consistent CFUs from the WDs and filters and to prevent future episodes. RESULTS: To understand the cause of the high counts in the WD unit, a designated member of the Estates Department carried out daily sampling of the port and bath water. The contributing factors identified as a result of this process were: • Low throughput through the processor, e.g., less than five washes per day meant that water was stagnant for prolonged periods. • The increased ambient temperature of the theatre environment. After introduction of a manual disinfection process of the WD and filters with a chlorine-based product results of “no growth” were obtained. An automated dosing/disinfection system was installed to aid the routine disinfection of filters and the WD. Random sampling of endoscopy equipment was also carried out during this period, and results were negative. LESSONS LEARNED: To understand the issue, a controlled sampling program was required that used standardized methods of sampling, reporting and recording results. Effective communication between theatre staff, Infection Control, Microbiology, and the Estates department was crucial in understanding and resolving the issues. This episode highlighted other areas of concern in endoscopy processing: • the suitability of the environment where endoscopy equipment was decontaminated and processed • evaluation of equipment against current guidelines to assess compliance, as the two WDs in use were several years old and had been purchased prior recent specifications for washer/disinfectors • a lack of standardized policies/procedures for handling, decontamination, and processing of endoscopy equipment.