Clinical Disinfection and Sterilization PDF

CLINICAL DISINFECTION AND STERILIZATION Dr. Michelle Siqueira,DDS, DSc Definitions Sanitation Cleaning Disinfection Sterilization Sanitation Public health conditions related to clean drinking water and adequate sewage disposal Health protection by providing a c...

CLINICAL DISINFECTION AND STERILIZATION Dr. Michelle Siqueira,DDS, DSc Definitions Sanitation Cleaning Disinfection Sterilization Sanitation Public health conditions related to clean drinking water and adequate sewage disposal Health protection by providing a clean environment that will stop the transmission of disease. Examples Hand washing Adequate processing for eating utensils and dishes Sterilization is not achieved Only products that do not alter the properties of food may be chosen Cleaning Removal of foreign material such as soil or body secretions Does not indicate sterilization or disinfection has taken place Often accomplished with soap and water Cleaning must remove debris from surfaces for effective sterilization and disinfection processes Disinfection Applies to inanimate objects only Eliminates pathogens but not necessarily all microbial forms, bacterial spores may survive Usually involves a chemical Antisepsis Term used for the specific kind of disinfection of tissue (usually skin or mucous membranes). Examples: chlorhexidine, povidone-iodine, isopropyl alcohol Sterilization A process that destroys all forms of microbial life including parasites, fungi, bacteria, bacterial spores, and viruses ***spores are very difficult to destroy, so if “Spores have been destroyed, then sterilization has occurred” Sterilization is an absolute term – an object is either sterile or not sterile How do we apply those in our settings? Developing Standard Operating Procedures (SOPs) for instrument processing A designated central sterilization room (CSR) is recommended Following local, provincial, and federal guidelines and regulations Stages of instrument processing: Wiping gross debris, discarding sharps Transportation to CSR Sorting instruments Cleaning Preparation and packaging Sterilization Storage This step is carried out in the unit (college SOP) College of Dentistry CSR CATEGORIES OF REUSABLE PATIENT CARE ITEMS Items that are not single-use/disposable must be sterilized and stored wrapped until point-of-care Single-use disposable items must not be re-processed The Spaulding Classification System Measures the risk of infection transmission based on the tissue that a specific instrument will contact during use Determines the level of disinfection/sterilization required CLASSIFICATION FOR DENTAL INSTRUMENTS: Critical Semi-critical Non-critical Critical Items: In contact with sterile areas of our body (break tissue) Have the greatest risk of transmitting infection Must be sterilized by heat Examples ✓ surgical instruments ✓ periodontal scalers ✓ scalpel blades  Items that are not single-use disposable must be sterilized and stored wrapped until the point of care Single-use disposable items must not be re-processed Semi-critical Items: Contacts mucous membranes or non-intact skin Lower risk of disease transmission All heat-tolerant semi-critical items must be sterilized If a semi-critical item is heat-sensitive, then it must be single-use  Examples: ✓ dental mouth mirror ✓ air/water syringe tips ✓ impression trays ✓ hand-pieces Items that are not single-use disposable must be sterilized and stored wrapped until the point of care Non-critical Items: Contacts intact skin Lowest risk of transmission of infection In the majority of cases: ✓ Cleaning ✓ Cleaning + disinfection if contaminated by blood, saliva, or other body fluids  Intermediate-level disinfectant – E.g., Optim wipes: ✓ Hospital-grade ✓ Have a Drug Identification Number (DIN) from Health Canada ✓ Tuberculocidal disinfectant – TB KILL TIME Examples: ✓ blood pressure cuffs ✓ radiograph head/cone, lead aprons ✓ pulse oximeter Items must be cleaned and disinfected between uses INSTRUMENT PROCESSING Operatory Clean-up: Handled contaminated instruments with care to prevent exposure to sharp instruments that can cause a percutaneous injury Disposable sharps such as needles and blades must be discarded in an appropriate container as close as possible to where the items were used Transportation Instruments should be put back into the cassette and the cassette should be closed while transporting Contaminated instruments should be transported to the Central Sterilization Room (CSR) immediately after treatment is complete Utility gloves MUST be worn Loose instruments should be in or on a container/tray, not carried by hand Instrument Processing Area Every oral health care facility must have a designated instrument processing area or room This area must be one-directional (dirty to clean) and have clear sections for: ✓ Receiving, cleaning, and decontamination ✓ Preparation and packaging ✓ Sterilization ✓ Storage of sterilized instruments  Dividers ✓ utilized to separate sections ✓ control traffic flow ✓ contain contaminants generated during processing ***If physical dividers are not possible, staff must be trained to understand space separations ***Always from DIRTY to CLEAN Instrument Cleaning Wipe all visible blood and other contamination as soon as possible Use of enzymatic products if cleaning is not immediately possible All instruments must be cleaned within 24 hours of usage Sterilization will not be achieved if the instrument surface has: ✓ Blood ✓ Saliva ✓ Debris Cleaning can be performed in two ways: Automated process (ideally) Hand scrubbing (higher risk to staff) Automated washer Best option for cleaning instruments Washers must be specifically designed for washing medical instruments – not a household dishwasher!!! AUTOMATE WASHER INSTRUMERNTS - Bing images Ultrasonic cleaner Uses a detergent solution + sonic action to break up and loosen debris on instruments Instruments are post-rinsed to remove chemical residue Solutions must be changed daily or sooner if there is visible bioburden (bacteria living on a surface that has not been sterilized) ultrasonic cleaner dentistry - Bing images Hand scrubbing Least preferable method Wear appropriate PPE, including eyewear, mask, and utility gloves Wash only 2 or 3 instruments at a time Long handled brush should be used, held in a downward direction and brushed away from user ***Increased risk of exposure Preparation and Packaging After cleaning, must be sterilized ✓ Clean means free of gross debris To ensure effective sterilization and instrument durability, prior to sterilization, instruments must be free of: ✓ biological debris ✓ disinfecting solutions ✓ chloride solutions ✓ detergents before heat processing  All instruments must be dry prior to processing Cleaned instruments must be inspected and placed into cassettes, wrapped, or packaged for sterilization All labeling should be done before sterilization, as packaging paper becomes less flexible after a sterilization cycle ✓ Name of the sterilizer ✓ Date ✓ Time  The force of a pen or pencil after sterilization could possibly pierce the packaging Packaging materials and techniques depend on the type of sterilization equipment used External and internal chemical indicators must be used with every instrument package Sterilization Heat sterilization is considered the most effective method in dentistry, particularly when combined with steam under pressure. Heat-tolerant dental instruments are sterilized in an oral health care facility using: Steam under pressure - autoclave Dry heat Steam Sterilization: Pulse vacuum autoclaves Class B autoclaves (also called pre-vacuum steam sterilizers) are most common in dental practices https://henryscheinequipmentcatalog.com/sterilization-room/autoclaves-sterilizers/scican-bravo Dry Heat Sterilization technique requires a longer exposure time (1.5 to 3 hours) and higher temperatures than steam sterilization Hot air oven Dry-Heat Sterilization: Principle, Advantages, Disadvantages – Microbe Online  Items must be arranged in the sterilizer in such a way as to permit free circulation of the sterilizing agent Instrument packs must be dry inside the sterilization chamber before opening, removing and handling Packaging materials must be specifically designed for the type of sterilization process utilized by the facility Chemical Vapor NOT an acceptable method of sterilization MUST use medical sterilization equipment specifically designed for the sterilization of instruments High-Level Disinfectants Liquid chemical disinfectants can’t be used to sterilize critical instruments in dentistry, because their effectiveness cannot be verified with biological monitors  STERILIZER TEMPERATURE PRESSURE TIME Steam autoclave 121 C (250 F) 15psi 15min unwrapped items 132 C (270 F) 30psi 3min Flash sterilization lightly wrapped items 132 C (270 F) 30psi 8min heavily wrapped items 132 C (270 F) 30psi 10min Dry heat wrapped 170 C (340 F) 60 min PSI: pound-force for square inch (unit that measures pressure) heavily wrapped items 132 C (270 F) 30psi 10min Dry heat wrapped 170 C (340 F) 60 min 160 C (340 F) 120min 150 C (300F) 150min 140 C (285F) 180min 121 C (250F) 12hrs Dry heat (rapid flow) 190 C (375F) 6min unwrapped items Dry heat (rapid flow) 190 C (375 F) 12min packaged items Chemical vapor 132 C (270 F) 20-40 psi 20min Ethylene oxide Ambient 8-10 hours As published by Jada, (Journal of American Dental Association) Vol 122 December 1991  Monitoring Sterilization - Inspection All sterilized packages, cassettes, and instruments should be inspected prior to use for: ✓ Package integrity (no rips, tears, or holes) ✓ Packaging must be dry ✓ External indicator has changed color ✓ Internal indicator has changed color ✓ Instruments are free of debris If the instrument, package, or cassette fails inspection, do not use it!!! Contents must be cleaned and sterilized again How to monitor sterilization? Mechanical monitors Chemical monitors Biological monitors ***Each indicator alone can’t assure sterilization; they indicate a package was exposed to sterilization **** They give us confidence that the sterilizer is functioning properly, and the instruments are safe for patient use after reprocessing ***Quality assurance Mechanical Techniques Assessing cycle time, temperature, and pressure digital displays printout on the sterilizer ***Record those for each load (10 years) ***Correct readings do not ensure sterilization; however, incorrect readings may be an early indication of a problem with the sterilization cycle  Chemical Indicators (CI) Classes I & IV Measure one or more of the physical variables of time, temperature, and pressure during the sterilization process Provide information about sterilization conditions on the outside and inside of each package by changing color Allow for detection of equipment malfunctions, and can help identify procedural errors, such as overloading or incorrect cycle selection  Class I indicator Class IV indicator Chemical Indicators Amazon.ca Indiamart.com Class IV indicator Safety.umbc.edu Sterilization Pouches & Sterilization Tubing - AdvanTech Sterilizers  CLASS II Sterilizer Air removal test for pre-vac sterilizers - Bowie-Dick/DART Detect air leaks and inadequate air removal Testing Should be used DAILY, before the first load is processed (run a warm-up cycle first) on the lowest shelf of an empty chamber directly above the drain Place a test pack in the autoclave and run a four-minute sterilization cycle (Bowie-Dick Cycle) It’s the color change that means that the steam is penetrating the test pack and pulling all the air out of the autoclave  Bowie-Dick https://erd-us.com/bowie-dick-biological-leak-tests-in-steam-sterilization/ DART Pass Fail file:///C:/Users/mfs603/Downloads/STERIS_DART-Daily-Air-Removal-Test-for-Steam-Sterilizers_Overview_LSFC-SS4103-A-EN- E%20(2).pdf https://consteril.com/bowie-dick-test/  Class V Chemical Integrating Indicators Designed to react to all critical variables Required in every sterilization load Considered to be the most accurate chemical indicator The strip should be placed in the middle of the chamber or within the densest instrument pack  Class 5 indicator Crosstex SPS STEAMPlus Class 5 Sterilization Integrator 1000/pkg - Valuemed Professional Products https://www.cdho.org/docs/default-source/pdfs/reference/guidelines/steam-chemical-indicators.pdf  Biological Indicators Biological Indicators (spore tests) are available as two different systems ✓ External ✓ In-house Why spores? Extremely hard to kill – if spores are eliminated there is assurance that other microbes that are easier to kill and part of our day-to-day will be killed too, confirming sterilization External: A paper strip BI containing bacterial spores is processed in a normal load and sent to a lab for incubation, to check if spores were eliminated. A report is sent back to the practice ✓ These strips are made of special filter paper inoculated with bacterial spores ✓ Provided by a mail-in system available through the College of Dentistry, University of Saskatchewan, or other external testing services ✓ Practices in Sask are required to complete WEEKLY tests for each sterilizer mesalab In-house: A BI vial is processed daily for each sterilizer with a normal load and incubated along with an unprocessed BI vial (positive control) at CSR  Biological monitors MUST also be used: ✓ New sterilizer ✓ Following sterilizer repair ✓ Introducing new packaging material ✓ Every load containing implants (usually delivered already sterile by the manufacturer) and/or the instruments used to place the implantable devices Results from both testing processes MUST be documented  POSITIVE SPORE TESTS: 1- Identify all sterilization packages since the last confirmed negative test and re-process all the packages prior to use. Always stamp identifying date, time, and sterilizer used to allow easy package identification 2- Repeated sterilization IMMEDIATELY after correctly loading the sterilizer and using the same cycle that produced the failure. 3- Review all records 4- REPORT ALL POSITIVE IN-HOUSE AND EXTERNAL BIOLOGICAL MONITORING SERVICE RESULTS TO THE REGULATOR 5- Sterilizer procedures must be reviewed, including packaging, loading, and spore testing. 6- Determine whether operator error could be responsible. 7- Common reasons for positive spore test (other than mechanical failure of sterilizer) – Human errors: ✓ improper packaging ✓ improper loading ✓ improper timing ✓ improper temperature ✓ improper method of sterilization regarding the item  If a mechanical issue is confirmed, the sterilizer must be removed from service until it has been inspected, repaired, and re-challenged with a biological indicator 3 times on an empty chamber Patients treated with instruments from a failed sterilizer (not caught early enough) must be contacted and referred for lab testing – very rare According to a database from the SWMS at our college, only 0.2% of dental practice autoclaves failed in the last 8 years, and 92% of failures were due to human errors, not mechanical issues Storage: - Ideally covered or closed cabinets - Check wrappers/packages before opening to ensure it is intact - Compromised wrappers/packages must be re-cleaned, re-packed, and re-sterilized - Open instruments in front of patients to visually demonstrate that the instruments have been processed The shelf life of in-house sterilized items should be based on: The quality of the packaging material The storage conditions The methods and conditions of transport The conditions of handling Internal policy Thank You!!!