Surgical Technology Principles - Decontamination, Sterilization, and Disinfection

Non-Immersible Sterile Equipment

  • Non-immersible sterile equipment exposed to blood/body fluids should be periodically wiped down during surgery (digital cameras, light cables, power equipment).

Close of Surgery

  • At the close of surgery, the ST separates equipment by category:
    • Sharp
    • Delicate
    • Heavy
    • Non-immersible
    • Immersible
  • Disposable sharps (scalpel blades, needles) are disposed of in proper containers.
  • Sharp instruments are placed in puncture-proof containers.
  • Instruments are placed in a separate basin, heaviest ones on the bottom, lighter on top.
  • Delicate instruments needing hand washing go in a separate tray/basin.
  • Water used to soak instruments is suctioned off before transport to prevent spills and contamination.
  • Equipment is placed on a covered/closed transportation cart for transfer to decontamination.
  • All instruments opened on the sterile field must be processed, even if unused, due to potential contamination from air droplets or direct contact.
  • These items should be separated from grossly soiled instruments for transport.

Transport of Soiled Instruments to Decontamination Area

  • Instruments and soiled equipment must be transported to the decontamination area in closed containers or a closed case cart.
  • Case cart systems involve loading sterile instruments and supplies onto a clean cart before surgery for transport to the surgical suite.
  • The ST is responsible for loading the cart and transferring it to the decontamination area for processing.
  • If a case cart isn't used, soiled items must be in leak-proof bags for transportation.
  • Biohazard transport containers (heavy plastic trays with safety locks) are an alternative for containing contaminated instruments.
  • Containers should withstand high temperatures and chemicals and have the biohazard symbol. (Vendors: Healthmark and Safetec).
  • Regardless of the system, it must be completely closed, leak-proof, and carry an orange/red biohazard label (occupational regulation).
  • The ST should transport instruments ASAP to the decontamination area after surgery; ideally, washing should occur within 20 minutes.
  • This prevents blood, tissue, and biofilm from drying, which can impede sterilization.
  • Upon arrival, the case cart is unloaded for washing, and the cart itself is decontaminated in a designated washer.
  • Clean carts are then ready for the next surgical procedure.
  • Fiber-optic endoscopes are often processed by perioperative staff and stored near the point of use, separate from the decontamination area.
  • Cleaning, disinfection, and sterilization require special techniques associated with the instrument design.

Instrument Cleaning and Decontamination

  • The decontamination area must be completely separated to prevent cross-contamination.
  • Sinks are designated only for washing soiled instruments.
  • Equipment and tools like brushes and stylets must be available.
  • The ultrasonic cleaner and washer-sterilizer are also located here.
  • A source of deionized/distilled water is needed for rinsing.
  • Compressed air is used for drying tubular instruments.
  • Chemicals like detergents, disinfectants, and enzymatic cleaners are available.
  • Eye wash stations must be accessible within 10 seconds of chemical exposure.

Decontamination Attire (PPE)

  • All staff in the decontamination area must wear PPE per OSHA regulations to protect from splashes and skin contact.
  • PPE includes:
    • Protective eyewear (goggles with side shields/full face shield)
    • Mask
    • Cuffed gloves approved for contact with chemicals
    • Full protective body suit/gown with waterproof apron and sleeves
    • Waterproof shoes and covers
  • PPE must be impenetrable by liquids. Routine surgical attire doesn't qualify, except for face shields and goggles.

Sorting Instruments

  • Instruments are sorted upon arrival in the decontamination area.
  • Instruments must be broken down into parts and separated by weight and complexity.
  • This prevents damage to delicate items and injury during reprocessing.
  • Small parts (pins, gaskets, screws) should be gathered and kept together.
  • Items are grouped by category:
    • Non-immersible equipment/instruments
    • Instruments with sharp edges/points
    • Gaskets, screws, pins, small parts
    • Heavy instruments
    • Delicate instruments
    • Heat- and pressure-sensitive instruments
    • Instrument containers
    • Basins and cups
    • Tubing, suction tips, hollow instruments
    • Instruments/equipment needing repair/replacement
  • Instruments must be cleaned before disinfection.
  • Dried blood, body fluids, and tissue debris trap microorganisms and cause instrument damage/malfunction.
  • Cleaning is performed by hand, ultrasonic cleaner, followed by automated washer/disinfector/sterilizer.

Hand Cleaning the Instruments

  • Delicate instruments are soaked in enzymatic detergent.
  • Instruments can be hand cleaned using warm water and enzymatic cleaner while immersed.
  • Water temperature should follow detergent manufacturer's directions (some detergents deactivate over 90°C90°C or 140°F140°F).
  • Instruments should be held under the water line to prevent releasing contaminated airborne droplets.
  • Areas difficult to clean are scrubbed with a small brush.
  • Attention is paid to hemostats, clamps, orthopedic rasps, and instruments that trap tissue/bone.
  • Items with a lumen (suction devices, tubing) are cleaned with a soft, narrow brush.
  • The correct-size brush must be used; brushes with bent or missing bristles aren't efficient.
  • Suction tips are cleared with a stylet (fine wire).
  • Instruments with channels/valves require disassembly.
  • Small parts should be kept together to prevent loss.
  • Non-immersible equipment/specialty instruments are cleaned per manufacturer's specifications.
  • Instruments must be completely rinsed in distilled/deionized water to remove all detergent/debris traces.

Ultrasonic Cleaning

  • The ultrasonic cleaner removes debris through cavitation.
  • High-frequency sound waves generate tiny air bubbles that implode, releasing debris.
  • The ultrasonic cleaner has recessed sinks filled with water and enzymatic cleaner.
  • Manufacturers state if the item can be exposed to ultrasonic energy.
  • Instruments must be fully opened.
  • Valves, stopcocks, and channels must be opened to allow water to contact all surfaces.
  • The water bath can become heavily soiled and a source of bacterial contamination.
  • Certain bacteria can colonize, leaving heat-resistant biofilm.
  • Fresh water and cleaner should be used on each batch; sinks must be emptied and dried daily and wiped with 70% alcohol.
  • Ultrasonic cleaning alone doesn't decontaminate or sterilize.

Washer-Sterilizer/Disinfector

  • Instruments are subjected to a cycle in the washer-disinfector after hand washing or ultrasonic cleaning.
  • Equipment has a single front-loaded chamber or a tunnel system for large quantities.
  • Instruments are loaded into trays securely to prevent damage.
  • Only the detergent recommended by the equipment manufacturer is used.
  • The full cycle includes immersion in a water bath and forceful water spray.
  • Some systems have an ultrasonic phase.
  • The load is rinsed and dried; most washers have an optional sterilization cycle.
  • Instruments are opened and hinges extended to their widest adjustment.
  • Instruments are placed in metal baskets and loaded into the washer chamber.
  • Steel basins, bowls, and containers are processed separately to prevent damage and ensure complete contact with water/steam.
  • After this process, instruments can be handled.

Reprocessing Cycle

  • Cycle of reprocessing: point of use, sort and disassemble, clean, decontaminate, inspect, assemble and wrap, storage.
  • Instruments must be processed correctly to be ready and safe for the surgical patient.

Cleaning at the Point of Use

  • Preparation of equipment and instruments begins at the point of use.
  • Instruments exposed to blood/body tissue are kept free of blood/debris to prevent caking and drying.
  • Dried blood and tissue make instruments difficult to operate and shouldn't be reintroduced into the surgical wound.
  • Wiping instruments reduces biofilm, which can prevent sterilization.
  • A sponge moistened with water can be used, or instruments can be placed in a basin of water.
  • Suction tips/cannulated instruments should be periodically flushed with water.
  • Saline is not used because it causes pitting, rusting, and corrosion.

Clean Assembly Area

  • The clean assembly area must be separate from the decontamination area to prevent cross-contamination.
  • The area includes a workroom with ample table space.
  • Attire includes a clean scrub suit, long-sleeved jacket, and head covering.
  • Large-volume sterilizers are adjacent to the clean work area for easy transfer of instruments after being arranged in sets and wrapped.

Assembling Instrument Sets

  • Instruments must be inspected for soil, stains, corrosion, function, and structural soundness before being assembled/wrapped.
  • Instrument sets are groups of instruments needed for specific surgical procedures.
  • Sets may contain a few or hundreds of separate instruments.
  • After inspection, instruments are stored as single instruments or wrapped in sets ready for sterilization.
  • Lists of instrument/equipment sets are maintained in a computer database or hard copy in the clean processing area.
  • Instrument lists are consulted to ensure all needed instruments are included and for counting purposes.
  • Surgeons may request additions to a standard instrument set; it’s important to communicate this to those responsible for maintaining and updating the lists.

Guidelines Instrument Set Assembly

  • Instruments are assembled in a way that protects them and facilitates sterilization.
  • Hinged instruments are opened (unlocked) and strung together with an instrument stringer or in racks to hold them open during sterilization.
  • Sharp/pointed items are turned downward to prevent injury and damage to the sterile wrapper.
  • Sharp/pointed instrument tips may be covered with plastic tip protectors to prevent damage and injury to the ST.
  • Some instruments must be disassembled for reprocessing; instruments not disassembled before disinfection may not be clean and should be returned for disassembly and repeat disinfection.
  • Instrument trays have a perforated bottom that allows the sterilant to circulate and adequately cover all surfaces.
  • Make sure no instrument tips are caught in the perforations, where they could be damaged; a cloth towel may be placed on the bottom of the tray to prevent damage (paper should not be used unless it's formulated without cellulose).
  • Heavy instruments are placed on the bottom of the tray, and others are packed/nested so they cannot shift and damage each other during processing.
  • For items with a lumen, a small amount of sterile, deionized (distilled) water should be flushed through the item immediately before steam sterilization only; this water vaporizes and forces air out of the lumen (air left in the lumen may prevent sterilization of its inner surface).
  • Remove stylets from suction tips for assembly so the sterilant can freely circulate inside the lumen.
  • Instrument trays should not contain separate items wrapped in peel pouch packages because air can become trapped and prevent steam from reaching all surfaces.

Washer-Sterilizer/Disinfector Continued

  • Instruments are lubricated after cleaning/disinfection to ensure smooth mechanical action.
  • This is used on stainless steel instruments and other selected equipment per the manufacturer's recommendations.
  • Only lubricants approved for use on specific medical devices are used.
  • Oils for internal mechanisms of power equipment must not be used for surface lubrication because the sterilization process may not penetrate the oil.
  • Steel instruments may be dipped in a combined lubricating and protective "instrument milk" as the final stage in cleaning/decontamination; instrument milk can also be added to the rinse cycle of some washer-sterilizers/disinfectors.

Special Handling of Ophthalmic Instruments

  • Ophthalmic instruments require special reprocessing to prevent toxic anterior segment syndrome (TASS).
  • TASS is an acute inflammatory condition that damages the anterior segment of the eye, potentially injuring intraocular tissue and causing vision loss.
  • It's most often seen after cataract surgery and is associated with instrument reprocessing.
  • Causative factors include contaminated ultrasonic cleaners, contaminated instruments, detergent/enzymatic cleaner residue, and glutaraldehyde use during sterilization.
  • Other factors include incomplete cleaning resulting in viscoelastic material residue and steam impurities during sterilization.

Ophthalmic Instruments

General Guidelines for Processing of Ophthalmic Instruments to Prevent Toxic Anterior Segment Syndrome (TASS)

  • During surgery, instruments should be wiped clean with a lint-free sponge and water.
  • At the end of the procedure, the instruments must be immediately submersed in sterile water.
  • Single-use cannulas (fine suction tubing) should be used if possible; if not available, the lumens of the cannulas must be flushed with sterile water immediately.
  • All phacoemulsification tips, tubing, handpieces, and other components must be flushed before they are disconnected after the procedure.
  • Use enzymatic cleaner at the close of surgery according to the manufacturer's instructions.
  • Only single-use brushes and syringes are used to clean ophthalmic instruments; these should be discarded after use.
  • Items that have been manually or ultrasonically cleaned should be wiped with alcohol before sterilization and dried according to the manufacturer's instructions.
  • All instruments should be inspected thoroughly for residue before sterilization.
  • For detailed guidelines on reprocessing ophthalmic equipment to prevent TASS, refer to the AAMI standard, AAMI ST79, and the American Society of Cataract and Refractive Surgery (ASCRS).

Instruments Exposed to Prion Disease

  • A prion is a protein particle that is not a cell and not related to bacteria or viruses.
  • Creutzfeldt-Jakob disease (CJD) and variant CJD are fatal diseases caused by prions.
  • These are highly infective in central nervous system tissue and are of special concern in instrument/equipment processing used on patients with known/suspected prion disease.
  • Prions aren't destroyed by normal mechanical/chemical sterilization.
  • Disposable supplies and instruments are used whenever practical in cases with a high/known risk for CJD or other spongiform infection.
  • During surgery on patients with known/suspected disease, instruments must be kept moist throughout the surgical procedure, preparation, and transport to the decontamination area because the prion rapidly adheres to dry stainless steel but is less viable in moisture.
  • The guideline for disinfection/sterilization of instruments that have been or are suspected to have been in contact with prions is published by the Society for Healthcare Epidemiology of America (SHEA).

Sorting and Inspection

  • After decontamination, all instruments are safe for handling and are taken to the clean assembly area for sorting and inspection.
  • The clean processing area is separate from the decontamination area to prevent cross-contamination.
  • The area includes a workroom with ample table space for sorting and assembling instrument sets.
  • Attire in the clean assembly area includes a clean scrub suit, long-sleeved jacket, and head covering.