[Subcontracting a steam sterilization activity: Impact on surgical instruments]

Subcontracting our institution's sterilization activity induced the implementation of an automated cleaning facility. Following this development, some of the resterilizable stainless steel needle holders started to show abnormal corrosion. Our study goal was to investigate the causes of this corrosion in order to optimize the sterilization circuit. A full sterilization process mapping and Ishikawa diagram enabled us to identify potential causes of corrosion. The needle holders' intrinsic characteristics, like steel quality and manufacturing, were analyzed as well as extrinsic factors such as the influence of preprocessing soaking conditions, steel passivation, water quality and the impact of corrosion inhibitors. Each potential factor of corrosion was tested in real conditions on needle holders' kits. The needle holders steel grade complies with medical standards and the tests showed that passivation and pre-processing conditions were not involved in the occurrence of corrosion, contrary to soaking length and use of softened rinsing water, containing more chloride than reverse osmosis water, and, thus conducive to rust formation. Moreover, corrosion inhibitors were deemed ineffective or incompatible. Due to this analysis, the incidence of corrosion was reduced by switching softened water to osmosis water and by introducing dynamic drying in the automated cleaning process. In addition, this work stresses the importance of minimizing waiting times and auditing the sterilization circuit before any subcontracting. Management Guidelines related to sterilization's outsourcing would probably have helped to limit this episode.