Water Quality Is Key to Surgical Instrument Reprocessing Outcomes

Total dissolved solids, pH levels, and iron levels are only a few components that must be considered.

The solutions used and procedures followed for reprocessing surgical instruments and medical devices are important; however, the quality and characteristics of the water used also determine the quality of the reprocessing and patient outcomes according to a poster presented at the 2022 Healthcare Sterile Processing Association Annual Conference & Expo (HSPA), held in San Antonio, Texas, April 23-27, 2022.

This topic is often covered at the HSPA conference. For instance, in 2021, Brian Flannigan, vice president for corporate sales and business development with Phigenics, an Illinois-based water management company presented about water quality. “There have been all kinds of issues that have been traced back to water systems over time. I would suggest that the awareness of that is increasing,” he then told Infection Control Today®.

The information on the poster at this year’s HSPA conference, titled “Water Quality Affects the Reprocessing Cycle,” sponsored and produced by BeliMed Infection Control, discusses ensuring adequate cleaning. The cycle is decontamination to inspection to preparation and packaging to sterilization to distribution and patient contact and back to decontamination.

AAMI ST79 and TIR 34 recommends using facility tap and purified water of acceptable quality to reprocess medical devices and surgical instruments. Also, using purified water is critical in the last step of decontamination processes to remove water contaminants and detergents residue to prevent straining, pitting, and corrosion of surgical instruments and medical devices.

What are characteristics that affect the longevity of surgical instruments and medical devices? According to the poster, water hardness; total dissolved solids; high conductivity chloride; and pH levels are key components that must be considered. However, copper, silica, and iron levels are also important to study. Medical devices and the performance of detergents can be reduced by water hardness. Total dissolved solids produce chalky residue on medical device chambers, and high conductivity stains and discolors surgical instruments and medical device chambers. Chlorides and pH levels lead to pitting and corrosion of instruments and affects the performance of medical devices. Copper, silica, and iron levels cause spotting and “snakeskin” patterns on instrument surfaces.

To emphasize why water quality is important, on the poster is the story of a patient who ended up with severe surgical site infection that stemmed from the water quality and the bacterial load in the final rinsing water of surgical instruments. Obviously, more effective measures are needed to control and eliminate the bacterial load in final rinsing water to protect reusable equipment from contamination in reprocessing and cleaning. In addition, water treatment process requires regular maintenance and is essential to eliminate pyrogens from the final rinse.

Another topic covered on the poster is steam for the cleaning process. AAMI ST 79 states that the steam supplied can be from facility steam generator or self-contained steam generators; however, a treated water supply is necessary to remove total dissolved solids and to ensure that supplied steam is within sterilizer manufacturer’s specifications. The water quality entering the boiler is a large factor in achieving the desired steam quality and content and to avoid contamination. Ultimately, poor water quality generates poor steam quality and the presence of particles in steam which may lead to corrosion and scaling of stainless surfaces and then to equipment malfunction. The equipment malfunction can cause wet packs (instruments staining and discoloration, or even pitting and rusting) requiring sterile processing staff to repeat sterilization cycles which can result in surgery delays. One final point on the poster was that the steam supply to the sterilizer accounts for about 60% of all wet packs, and 30% of all wet pack incidents are because of sterilizer performance.