Surgical instrument washer disinfector cycle temperature treatments and washing times have rendered sterile surgical instruments, at the completion of the process, when reprocessing surgical instruments, prior to terminal sterilization.
APIC Association for Professionals in Infection Control
Presented by: A. Drake, RN, Director CS, Ohio State University,
International Annual Conference of APIC, May 5, 1991, Nashville, Tennessee
Oral Presentation by Ann Drake, President of APIC
The application of universal precautions to instruments/utensils handling became an issue in the selection of replacement decontamination equipment for Central Sterile supply at our hospital. The new technology of an automated Surgical Instrument Washer Decontaminator, used with a combination enzyme surgical instrument cleaner detergent, offered increased protection to our reprocessing staff due to decreased handling but raised concerns about the efficacy of thermal disinfection as opposed to the traditional washer sterilization.
Because of the limited scientific documentation pursuant to the efficacy of surgical instrument washers, a study was undertaken to establish the microbial safety of finished products and to identify any feature or function failure which could adversely affect the washing outcomes.
The sequential functions of the Surgical Instrument Washer Decontaminator progress from flush/rinse enzyme cold water washing, elevated temperature detergent washing, redundant rinses, lubrication with deionized water (DI) sprays, and to drying at 240° F, for 4 minutes. The Washer Decontaminator was challenged with selected instruments and utensils that are considered to be very difficult to clean. Included were 30 each of stainless steel non-perforating towel clips and stainless steel and glass medicine cups. Each item was rinsed (contaminated) with a 105 ml suspension of Staphylococcus aureus, Pseudomonsaeruginosa, Enterococcus fecalis and Candida albicans, in nutrient media, and then dried. The instruments were processed in the Washer Decontaminator, in 3 separate loads during times of high volume SPD operation. All products were tested for sterility. Ten separate cultures were taken of the final rinse solution of instrument lubricant and de-ionized water prior to the drying cycle. A separate culture was taken of the instrument lubricant fluid.
All instruments and utensils tested were sterile at the completion of the cleaning process.
The Surgical Instrument Washer Decontaminator using the proper sequence of treatments, and a combination enzyme detergent lubricating cleaning concentrate, is a valid replacement for the conventional Washer Sterilizer. Surgical instrument washers and washer disinfectors, that are properly designed, can deliver sterile medical devices at the completion of the washing cycles. The proper sequence of surgical Instrument washer disinfector cycles will deliver consistently clean medical devices that are safe to handle and have received the prerequisite for sterilization. An example of proper cycle washing temperatures:
- cold water pre wash cycle: ambient to 95 F, 35 C
- wash enzymatic and detergent cycle: 131 to 137 F, 55 to 58 C
- elevated thermal rinse cycles witjh lubrication: 194 to 209 F, 90 to 98 C
- hot air dry cycle with disinfecting temperatures: 158 to 230 F, 70 to 110 C
In the United States manufacturers of surgical instrument washers are not approved by the FDA to market their products as "washer disinfectors", however, many of the surgical instrument washers are manufactured to produce the times and temperatures that can effectively deliver disinfected surgical instruments. Automated surgical instrument washer decontaminator disinfectors can safely contain within their chambers the cleaning-decontamination-reprocessing functions, removal of debris, and contaminated aerosols. It has been demonstrated that a properly designed surgical instrument washer decontaminator and washer disinfector, that is used to the manufacturer’s specifications, will consistently and repeatedly remove all microorganisms from surgical instruments. Surgical instrument washers and medical washer disinfectors should be used in accordance with the manufacturer’s direction for use, to secure the most consistent and efficacious results. Worker safety and reprocessing efficacy can be compromised by violating the manufacturer’s recommendations.