Cleaning efficacy of medical device washers in North American healthcare facilities

SummaryThe objective of this study was to determine the worst case levels of organic soil on surgical instruments and whether the commercially available TOSI® provided a clinically relevant organic challenge to an instrument washer. Our data showed that protein and haemoglobin levels (374 and 111 μg/cm2, respectively) from the instruments evaluated correlated with those on a TOSI that had a visual score of 2–3 (267 and 60 μg/cm2, respectively). However, the regular TOSI (without the plastic cover) and the TOSI Lum-Chek do not present difficult cleaning challenges; therefore, a visual TOSI score of 1–5 after processing in an automated washer represents a serious cleaning problem. Our results showed that surgical instruments may have high post-cleaning levels of carbohydrate (up to 352 μg/cm2) and endotoxin (up to 25 373 EU/cm2), suggesting unrecognised issues with the quality of water used for the final rinse. The average carbohydrate and endotoxin levels post procedure and before cleaning were 138.9 μg/cm2 and 18.14 EU/cm2, respectively. The average protein and haemoglobin levels both showed >99% reduction in levels post cleaning. Our data support the need to monitor the water quality used in instrument washers. In addition, there is an urgent need for establishment of standardised criteria for rapid cleaning indicators for instrument washers to ensure that they provide a clinically relevant method for monitoring washers used in healthcare facilities.