Water quality, type affects instrument reprocessing outcomes
Consult AAMI TIR34:2014/(R)2021 for reference
First of a two-part series
By James Schneiter
Protecting patients from the dangers of a surgical infection caused by a device that remains contaminated after processing is the No. 1 responsibility of everyone who comes in contact with the device. The responsibility for safe, effective processing starts with pre-treating the device at point-of-use and continues all the way through its delivery back to surgery. Part of this responsibility includes ensuring the quality of the water that is used to process the device.
While often overlooked, water is important for all stages of reusable medical device processing. Water is required for decontamination, soaking, manual or automated cleaning, rinsing and the final disinfecting rinse. Additionally, all concentrated instrument cleaners are over 90 percent water that acts as the solvent for all of the chemicals in the cleaner. Water quality is a key safety component of medical device processing to ensure that devices are safe for patient use and do not cause an adverse event?in a patient. (1)?
It is important that personnel who process medical devices, or who use them in procedures, understand how the quality of the healthcare facility’s water can have an impact?on the processing equipment, as well as the devices and instruments themselves. It is also important that personnel recognize that the quality of water should be regularly monitored to ensure that the control measures used to ensure water quality are working properly. (2)?
Water that is safe to drink may not be acceptable for processing or for sterilizing surgical devices. Water quality varies from place to place and according to the season of the year. Most public water systems include additives such as chlorine, dissolved salts and sometimes significant naturally occurring mineral content, and even organic contaminants, bacteria and endotoxins. (3)?
Almost all municipal tap water is contaminated with varying levels of toxic heavy metals, synthetic organic chemicals, biological parasites and hundreds of other harmful contaminants. According to a research group, “EPA reports show that U.S. water supplies contain over 2,300 cancer causing chemicals.”(4) Regretfully, most water treatment facilities in use today were not designed to remove organic chemicals and toxic heavy metals such as lead.?
Depending on water hardness and temperature, fresh water used in device processing can lead to the formation of hard water deposits, a layer of lime or scale that is difficult to dissolve. Additionally, corrosion may occur under these deposits. When water evaporates, some substances can remain as visible mineral residues. Water supports the growth of Gram-negative bacteria. Calcium, magnesium and water pH can stain instruments and inactivate disinfectants.
When it comes to cleaning agents, the majority of them are labeled by the manufacturer for use with ‘Utility Water’ which, depending on the facility, may be simple tap water. Distilled, reverse osmosis or deionized water is recommended for use as a dilution agent with some concentrated instrument cleaners and with certain approved disinfectants. It is imperative that you follow the manufacturer’s published instructions when preparing the product for use. (5)
Contrary to its name, “stainless” steel instruments can in fact become stained over time. “Water can also damage stainless steel instruments. Stainless instruments are susceptible to pitting when there is an increase in the chloride content in the water, when there is an increase in temperature, with decreasing pH values, increased exposure times, insufficient drying and concentration of chloride from dry residues to instrument surfaces after evaporation.” (6)
Poor water quality adverse effects
Water impurities can be the cause of many adverse effects on medical device processing. Reusable surgical instruments can show signs of corrosion, scaling and pitting caused by water impurities. The buildup of biomass, increased microbial and/or endotoxin content on instruments are also the result of the impurities in tap water.
When it comes to device processing, water impurities can significantly decrease the effectiveness of commercial detergents thus compromising the cleanliness of the instrument. In addition to being harmful to instruments, over time, water impurities will buildup in the water supply system and cause biofouling or mineral scaling within the facility’s piping. Finally, and most importantly, water impurities can lead to an instrument that remains contaminated after processing being returned to surgery and infecting a patient. (7)
Monitoring water quality is a key part of ensuring safe and effective device processing. When it comes to water quality for use in medical device processing, two general characteristics need to be considered and monitored. First is the microbial level in the water. Second are the inorganic and the organic components of the water. Ensuring safe water quality in device processing requires collaboration between the personnel who process medical devices and the personnel who establish and maintain the water treatment system. (8)?
AAMI TIR34: 2014/(R)2021?
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AAMI TIR34: 2014/(R)2021 is designed to provide facilities with guidelines and recommendations on the quality of water that should be used in each stage of medical device processing. It also provides recommendations and standards for each category of reusable medical device.?Additionally, it includes annexes that provide technical information?to water maintenance personnel to guide them in configuring and monitoring water treatment systems. This would include personnel such as Facilities Engineering, Facilities Management, etc., who are involved in water treatment and distribution in the facility. (9)
In addition to providing general guidelines and recommendations, AAMI TIR34: 2014/(R)2021 provides specific parameters and recommendations for the quality of the water used to clean, rinse, disinfect, and sterilize medical devices. It defines water types on the basis of hardness, pH, microorganism levels, endotoxin levels, and other characteristics. The following topics are covered:
About the author:
Prior to his retirement in December 2018, James Schneiter had been the founder, owner and president of?America’s MedSource Inc.,?which designed, developed, licensed and marketed a variety of implantable vascular devices, laparoscopic devices and neurosurgical instruments. Schneiter has nearly five decades of experience in medical device design and production and is a recognized expert in the area of instructions for use (IFU) and independent laboratory IFU validation studies. He also is a co-founder of #IFUcan. Schneiter can be reached at [email protected].
References:
1. “AAMI TIR34 – Water for the Reprocessing of Medical Devices” https://www.evoqua.com/en/articles/AAMI-TIR34-water-for-medical-devices/
2. Op. Cite.
3. “Water for Instrument Processing” Marcia Frieze, Infection Control Today, April 29, 2009
4. Water Filter comparisons.?https://www.waterfiltercomparisons.com/water_filter.php
5. “Water for Instrument Processing” Marcia Frieze, Infection Control Today, April 29, 2009
6. Op. Cite.
7. “AAMI TIR34 – Water for the Reprocessing of Medical Devices” https://www.evoqua.com/en/articles/AAMI-TIR34-water-for-medical-devices/
8. Op. Cite.
9. www.aami.org
10. Op. Cite.