Sterilization and Disinfection

Sterilization (Chapter 11)

• Sterilization is the complete inactivation or destruction of all microorganisms, including spores.
• Bacterial spores are the most difficult type of microorganism to kill.
• The number and type of microorganisms, and their resistance/death rate are factors that affect the effectiveness of sterilization.
• D-value refers to the time needed to kill 90% of microorganisms on a device.

Spaulding’s Classification System

• According to Spaulding's classification system, medical devices are classified into three categories: non-critical, semi-critical and critical.
• Non-critical devices require low to intermediate level disinfection.
• Semi-critical devices need high level disinfection.
• Critical devices demand sterilization.

Device Preparation and Sterilization Factors

• Devices should be as clean as possible before sterilization.
• Protein left on a device will coagulate with the heat from the sterilization cycle, thereby protecting microorganisms.
• Moisture, temperature, and time are the three factors that all methods of sterilization must have control over.
• A medical device’s compatibility with a sterilization method is determined by the manufacturer’s instructions.
• Reposable devices can only be processed a limited number of times.

Sterilizer Cart Logistics

• Packages on a sterilizer cart should have 1 to 2 cm space between them.
• Peel pouches should be positioned on the sterilizer cart on edge, paper to plastic.
• Cupped items should be positioned on the sterilizer cart on edge and tilted forward.
• Medical devices placed on a solid bottomed tray, should be positioned on edge on the sterilizer cart.
• Steam sterilization is the method of choice.

Steam Sterilization

• The advantages of using steam sterilization are that it is relatively fast, non-toxic, economical, readily available, and effectively penetrates lumens and mated surfaces.
• Disadvantages of steam sterilization include that it requires air removal, is unsuitable for items sensitive to heat and moisture, requires a cool down time, and requires quality steam.
• Steam with good quality contains 97% steam and 3% water.
• For steam sterilization, heat coagulates protein and kills cells.
• Moisture is a better conductor of heat than dry air, so moist heat acts more quickly to destroy cells.
• Higher pressures allow steam to come to higher temperatures.
• Steam temperature at 0 psi: 100°C
• Steam temperature at 15 psi: 121°C
• Steam temperature at 27 psi: 132°C
• Steam temperature at 30 psi: 135°C
• Effective microbial kill in steam sterilization requires time, temperature, and saturated steam.
• The exposure phase begins once all air is removed from the chamber, steam fills the chamber and the appropriate temperature is reached.

Sterilizer Parts

• The chamber is where sterilization occurs, so the walls must be very strong to resist the increase in pressure during the sterilization cycle.
• The door allows for loading and unloading of the sterilization chamber, so the door must be very strong to withstand the increased pressure during the sterilization cycle.
• The door becomes part of the chamber when closed.
• The jacket on a steam sterilizer is a space of 3 to 4 inches surrounding the sterilizer chamber that continuously circulates steam.
• The purpose of the jacket on a steam sterilizer is to maintain a ready supply of steam.
• The continually circulating steam keeps the walls of the chamber warm, preventing condensation from forming when steam enters the chamber.
• The sterilizer drain (air outlet) allows air to escape at the start of the cycle, and steam to escape at the end of the cycle.
• The steam trap closes off the sterilizer chamber once all air has been removed.
• The baffle deflects the steam entering the chamber, preventing it from directly contacting items and causing condensation.

Sterilization Records

• The three variables measured on a steam sterilization printout are time, temperature, and pressure.
• Sterilization records must be kept for a minimum of 2 years.
• Steam sterilization records must contain the sterilizer ID number, date and time of sterilization, temperature, pressure and exposure time, total length of the sterilizing cycle and lot number of items processed.
• Steam sterilization records must also contain the initials of sterilizer operator, conditioning time, sterilizer cycle count, dry time, and any failure codes or aborts that occurred during the sterilization cycle.

Sterilization Cycle Phases

• The four cycle phases in steam sterilization are conditioning, exposure, exhaust, and drying.
• During the conditioning phase, air is removed and steam is injected, and pressure and temperature increase.
• During the sterilization (exposure) phase, the sterilizing temperature is maintained for the recommended amount of time.
• During the exhaust phase, steam is removed from the chamber through the drain.
• During the drying phase, the vacuum pump continues running, creating a vacuum in the chamber.
• The five common types of steam sterilization cycles are pre-vacuum, gravity displacement, steam-flush pressure-pulse, liquid, and immediate use steam sterilization.
• Pre-vacuum sterilization uses a vacuum pump to remove air from the chamber at the beginning of the sterilization cycle, and remove steam at the end of the cycle.
• The vacuum assists with the drying of the items
• Gravity sterilization does not use a vacuum pump.
• As steam enters the chamber, air is forced out through the drain.
• Steam-flush pressure-pulse sterilizers use a sequence of steam flushes and pressure pulses to remove air from the chamber and is commonly used in tabletop sterilizers.
• Gravity sterilization is suitable for items that cannot tolerate higher pressures.
• Disadvantages of gravity sterilization is that it is a slow process and air can be trapped in pockets
• Air pockets prevent the steam from contacting the device, and the liquid sterilization cycle uses a slow exhaust at the end of the cycle.
• A main difference between a liquid sterilization cycle and pre-vacuum or gravity sterilization is that the liquid sterilization cycle uses a slow exhaust at the end of the cycle.
• Immediate use steam sterilization should be used in emergency situations (life, death or loss of limb situations)
• Items that should never be sterilized in IUSS include implants, organic material or complete instrument sets.
• When unloading the sterilizer cart, finding one package with moisture on the outside, and all of the other packages on the cart are dry deems the package a wet pack.
• A wet load would consist of two or more wet packages.
• Moisture on the outside of packages is caused by condensate dripping onto packages from the sterilizer railings, shelves or packages on the shelf above.
• Moisture on the outside of packages can also be due to condensation or improperly trapped steam lines.
• Moisture on the inside of a package may be due to heavy or dense instrument sets, failing to put absorbent material between basins, textile packs that have been wrapped too densely or improperly prepared items (items not dried).
• Wet packages should not be used because moisture on or inside of a package can create a pathway through which microorganisms can enter the packages.
• The most common causes of wet packs include improper loading, improper packaging, a plugged drain line, a dirty chamber or wet steam (more than 3% water)
• Wet steam is caused when water boils to violently, it releases water vapor and large water droplets.
• Sterilized loads should be cooled on a wire or well-padded shelf, in an area away from drafts and air-conditioning vents
• Touching packages before they have been allowed to cool completely should be avoided, because microorganisms on the hands could be transferred into the moist packages.
• Steam sterilizers should be cleaned at least once per week.

Low Temperature Sterilization

EtO Gas

• EtO gas is odorless at low concentrations and smell sweet at higher concentrations, flammable and explosive, toxic, and penetrates plastic or rubber but not metal or glass.
• Aeration for EtO sterilization allows EtO to be completely removed from devices.
• Aeration is important because any remaining EtO is extremely toxic and will cause harm to patients and staff.
• EtO abators converts Eto gas into Carbon Dioxide and water vapor, which is then safely dispersed into the atmosphere.
• The four requirements for EtO sterilization are Eto concentration, humidity, time and temperature
• Moisture is necessary in the EtO sterilization process because it participates in the reaction between EtO and the cells of microorganisms, softens the cells, allowing Eto to penetrate the item and destroy the cell more easily.
• It is important to dry items prior to sterilizing in EtO because EtO is 100% soluble in water, so excess water will absorb the Eto, which could then remain on the device.
• Higher temperatures improve the penetration of EtO.
• The minimum temperature for an EtO sterilization cycle is 26°C.
• Most EtO sterilizers operate between 50°C and 60°C.
• The common range of exposure time for EtO sterilization is 1 to 3 hours.
• The five phases of an EtO sterilization cycle are conditioning, charge, sterilization, exhaust, exhaust (purging)
• The bacteria spore used for biological indicators for EtO is Bacillus Atrophaeus.
• During the conditioning phase of EtO sterilization air is removed from the chamber using a vacuum.
• During the charge phase the vacuum is maintained, moisture is injected and EtO is injected into the chamber.
• During the sterilization phase Eto concentration, humidity, temperature, and pressure (or vacuum) are maintained for 1 to 3 hours.
• During the exhaust phase a deep vacuum removes EtO from the chamber.
• During the exhaust (purging) phase, filtered air is drawn into, then removed from the chamber to remove EtO. This is repeated.

H2O2 Sterilization

• Powders, liquids and cellulose materials cannot be sterilized in H2O2 sterilizers.
• If there is moisture remaining on a device in H2O2 sterilization, the H2O2 is absorbed into the moisture, and the cycle aborts due to low concentration.
• Sterilization labels (stamps) should be added to items sterilized in H2O2 after they are removed from the sterilizer.
• The 5 phases of the H2O2 sterilization cycle are conditioning phase, charge phase, H2O2 elimination phase, vent phase.
• The four critical variables for H2O2 sterilization are temperature, time, H2O2 concentration, and plasma.
• If an H2O2 sterilization cycle aborts, the load should be marked as failed, the items removed from the sterilizer wearing gloves, and the items should be returned to decontam for complete reprocessing.

Steris Systems

• System 1 uses S20, and the Plus/Express uses S40 sterilant.
• Both sterilants are peracetic acid.
• Items sterilized using Steris Systems cannot be stored, because The Steris Systems are a point of use sterilization technology.
• The Steris Systems achieve sterilization via immersing devices in the sterilant concentration.
• Steris Systems sterilization cycle phases are conditioning, exposure and rinse/air purge phases.
• Steris 20 chemical indicators change from purple to white.
• Steris 40 chemical indicators change from blue to pink.
• The bacterial spore used for the biological indicators for Steris systems is Geobacillus stearothermophilus
• Steris System machines should be cleaned daily.
• A cloth moistened with 70% isopropyl alcohol should be used.
• Water should not remain underneath the tray.
• A diagnostic cycle should be run on the Steris Systems each day that the machine is in use.

Other Sterilization Methods

• Disadvantages of dry heat sterilization include that dry heat does not conduct as well as moist heat, so cycle times are much longer.
• The common cycle times and temperatures for dry heat sterilization cycles are 160°C for 2 hours or 162°C for 1.5 hours.
• The two types of dry heat sterilizers are gravity oven and mechanical oven.
• Packaging materials that can be used with dry heat sterilization include muslin, metal cannisters, glass jars, aluminum foil.
• Irradiation (Gamma sterilization) is used to sterilize single use devices.
• The two processes used to sterilize single use devices are Gamma or EtO

Quality Assurance Monitoring

• Installation commissioning ensures that the sterilizer was installed according to the manufacturer's specifications.
• Operational qualification is done to verify that the sterilizer is meeting the manufacturer's performance specifications.
• Performance qualification confirms that the sterilant can effectively sterilize the typical loads and devices used in the facility.
• Routine monitoring is done regularly to ensure that equipment is functioning as it should.
• The manufacturer or designate is responsible for performing installation commissioning
• Operational requalification should be done yearly, when the sterilizer is moved, if there is any change to the steam supply or delivery, if there are any major repairs to the sterilizer and any time there is an unexplained sterility failure.
• Operational qualification and requalification is performed using 3 consecutive biological indicator PCDs, and also 3 consecutive air removal tests (bowie-dick)
• Physical, chemical and biological monitors are the three types of indicators used to monitor the sterilization cycle
• The sterilizer printout is the monitor of physical parameters.
• Physical parameters should be checked before removing the items from the sterilizer.
• A color change on an internal chemical indicator does not guarantee the sterility of the devices.
• Sterility is dependent on the cleanliness of the devices, but the Cl indicates that the conditions for sterilization were met within the package.
• Every set must contain an internal chemical indicator.
• If an instrument set has four layers, four internal chemical indicators are required.
• When examining a Bowie-dick test pack, an even color change should be observed.
• The Bowie-Dick PCD should be placed horizontally, over the drain in the sterilizer chamber
• Tests should be performed, 3.5 to 4 minutes at 132°C with no drying phase

Chemical Indicators

• Type I emulating indicators respond to ALL critical variables for a specific sterilization cycle.
• Type II integrating indicators respond to all critical variables.
• Type III indicators respond to ONE process variable.
• Type IV indicators are designed for a specific test like Bowie-Dick.
• Type V indicators respond to two or more critical variables.
• Type VI are external process indicators.

Bowie-Dick Test

• The parameters for the Bowie-Dick test are 3.5 to 4 minutes at 132°C, and there is no drying phase.
• A Bowie-Dick test should be performed as the first load of the day, every day that the sterilizer is in use.
• Internal chemical indicators should be placed in the most difficult to sterilize area of the package.
• The most difficult area is the least accessible to sterilant penetration.
• A negative Bl means all of the spores in the BI were killed during the sterilization cycle, which is a pass.
• A control BI must be had each day and for each new lot number of Bls
• The control BI should be positive for growth, which assures that the lot of Bls contained live bacterial spores.
• The bacterial spore used in biological indicators for steam is Geobacillus staerothermophilus.
• PCD stands for process challenge device, and duplicates the most complex package that may be sterilized in the sterilizer.
• The biological indicator PCD should be placed on the lower shelf directly over the drain in the sterilizer chamber.
• BI PCDs must be added to steam sterilizer loads in the first load of the day, and any load with implants
• Not all BI PCDs are the same, there are BI PCDs designed for specific sterilization temperatures and air removal testing.
• Sterilizer lot labels must contain the date of sterilization, sterilizer number, load number and lot number.
• A sterilizer load should be quarantined while waiting for the results of the biological indicator.
• If a Bl is positive for growth a recall must be initiated.
• All devices that were sterilized in that machine up to the last successful (negative) Bl result must be found and quarantined.
• The sterilizer must be retested with a biological indicator and if the retest is negative for growth, the quarantined items may be released, and the sterilizer may continue to be used.
• If the retest is positive for growth, all items in the quarantined loads must be returned to assembly for re-wrapping.

Storage And Distribution

• Tier 1 sterile storage areas are in MDRD or within the operating room (center core)
• Tier 2 sterile storage areas are outside of the MDRD, but still within the hospital (nursing units)
• Tier 3 sterile storage areas are warehouse areas that store and distribute open inventory.
• Cardboard or paper boxes should not be used to store sterile supplies, because they cannot be cleaned.
• Outside shipping containers should not be brought into the MDRD, because shipping containers can have contaminants on the outside that cannot be removed.
• The sterile storage area must be at the end of a one-way workflow, near the processing area, and have restricted access.
• Sterile items should never be stored in corridors, operating rooms or patient care areas.
• The temperature and humidity requirements for the sterile storage area is 18 to 23*C and 30% to 60% humidity
• Shelving in the sterile storage area should be cleaned every 3 months
• Medical devices should be stored 25 cm (10") off the floor
• Medical devices should be stored 45 cm (18") from the ceiling.
• Medical devices should be stored 5 cm (2") from an outside wall.
• Top and bottom shelves must be impervious and the floors in the sterile storage area should be wet mopped daily.
• Store items of the same type together, to minimize backtracking, items that are frequently requested together should be stored together, items that are frequently requested should be stored close to the dispatch point.

FIFO

• FIFO is first in first out and the packages sterilized should be the first ones used.
• FIFO practiced involves storing items to the left, and taking from the right
• FIFO practiced involves storing at the rear and taking from the front.
• FIFO practiced involves storing from the bottom and taking from the top.
• Event-related sterility is when items that have gone through a sterilization process are considered sterile until an event occurs to compromise the package integrity.
• Events that may compromise the integrity of a sterile package include itmes being wet, packages being opened, packages visibly soiled or dropped on the floor.
• A sterile package must be inspected for an external indicator, package integrity, and tamper-evident arrows prior to sending for use.
• Central dispatch, top-up/exchange cart, and case cart are the three most common methods of distribution.
• A central dispatch system releases items to the units as they are requested; items delivered by the MDRT or picked up by the unit.
• A top-up/exchange cart system has quotas based on actual use; the quota is the number that should be on hand and then Inventory should be taken, a pick list generated, and items are filled as required.
• A general case cart system features case carts containing a standard, predetermined selection of supplies for a specific procedure.
• A specific case cart system involves case carts with the supplies for a specific procedure, as well as items specific to the surgeon's preferences and patient needs.
• A missing list should be created and items should be filled before sending the cart to the OR, when items are missing from case carts.
• The transport container must be closed and leak proof, when transporting sterile supplies through a facility.
• The KanBan system splits product’s quota in half with Half the quota being placed in a bin in the front, the other half in the back, then when the front bin is empty, the back bin is moved forward, and a new bin is placed in behind.

MDRD Accountabilities and Quality Systems

• Internal stakeholders include MDRTs, nursing units, DI, OR, IPC, Biomed, and physicians.
• External stakeholders include vendors, suppliers, government, professional associations and the community.
• External organizations that provide standards and guidelines that must be followed in the MDRD include CSA, Accreditation Canada and PIDAC.
• The Workplace Safety Insurance Board (WSIB) provides wage loss benefits and return to work help as well as perform worksite inspections.
• The Workplace hazardous material information system (WHMIS) is A system for providing health and safety information on hazardous products
• Quality healthcare is The degree of excellence to which an organization meets the clients' needs and exceeds their expectation.

Essentials Of Quality System

The elements of a quality system necessary in an MDRD are:

• Written policies and procedures.
• Personnel policies for qualification, responsibilities and reporting relationships.
• Process controls that ensure procedures are being followed.
• Continual improvements in all aspects of the facility's operations.
• The main function of a quality management system(QMS) ensures consistency in the facility's processes and documentation, to produce quality products that meet the requirements of the customer and regulations.
• Key Performance Indicators (KPIs) are used to evaluate assess and document the quality of the MDRDs processes.
• The selection of KPIs is based on local regulations, requirements of the standard and the goals and objectives of the organization and the MDRD.

Requirements for Quality Management System

The Quality Management System (QMS) must include:

• Policies and procedures that are reviewed at regular intervals.
• An organization chart showing the responsibilities of all personnel in the MDRD.
• Qualification requirements for all staff and management (roles, responsibilities and accountability) A process for continual improvement.
• Customer-focused approaches, requirements and services.
• A communication plan for internal and external stakeholders.
• Performance indicators and a means to measure and monitor
• Processes for change control, management of adverse events, management of drugs and products and product recalls.
• Infection prevention and control processes and occupational and environmental health and safety processes.
• Processes for regular management review of: Client issues and follow up, resources and KPIs.
• Any changes that could affect the QMS.
• Follow-up actions from previous management reviews, preventative actions based on risk analysis and documented action and objectives coming from the management review that will foster improvement.

Key Terms

• A policy is a guiding principle that sets direction for an organization.
• A procedure ensures the consistency of each product, process and service provided.
• Manufacturer's instructions for Use (MIFUs) are the written instructions from the medical device manufacturer that contain the necessary information to reprocess a device safely.
• They must be easily accessible to all staff.
• Total quality management (TQM) is an organization-wide approach to improve the organizations processes and quality.
• Scenarios that may be involved in TQM are improving organizational processes, improving products and improving services.
• A balanced scorecard is a management tool that balances financial and operational measures relating to customer service, internal business processes, financial performance and learning and growth.
• It considers the entire unit performance, and does not use financial performance as the single determining factor or success.
• Benchmarking is when a hospital compares its reprocessing activities to that of other, similar, hospitals.
• Six Sigma uses data to eliminate defects, measure how far from perfection a process is, eliminate waste, thereby increasing efficiency and reducing production time and cost.

Accountability

• The four elements that must be present to prove negligence in court include duty to meet the standard of care, breach of duty to meet the standard of care, breach of duty which causes foreseeable harm, and causing actual harm or injury
• Vicarious liability involves the healthcare setting accepting responsibility for the actions of its employees.
• Reactive and proactive risk management are the two approaches to risk management.
  • Reactive is when occurrences after the incident occur, whereas proactive involves preventing the next incident.
• Incident reporting is important, because it helps the healthcare facility to identify potential and actual risks, thus eliminating hazards.
• Proper ergonomic design is important, as it prevents injury from repetitive strain and static postures.

Community Healthcare Setting

• Challenges that may be faced when reprocessing devices involved complex and evolving instrumentation, maintaining and updating MIFUs and documentation, while upholding time and efficiency requirements in the midst of staff training in response to environmental challenges.
• Effective education programs for MDRTs working in a community healthcare setting include risk awareness for diseases, and immunization methods.
• Effective education programs also involve hand hygiene, transmission protocols, risk of infection, sanitation, assembly, packaging, sterilization, storage, equipment cleaning as well as monitoring of reviews.
• Risk assessments should be performed at time of booking , upon arrival at waiting room and in exam room.
• Barriers to hand hygiene involves nail polish, artificial nails, wearing watches and long sleeves.
• ABHR is preferred method of hand hygiene unless hands visibly soiled.

PPE

• Types of PPE include: Gloves, gown, facial protection (mask, eye shield)
• Prescription eye glasses are not sufficient eye protection (don't provide protection from splashes coming from below or the side.
• Three different areas requiring environmental cleaning in a community healthcare setting include:
  • Public areas like waiting rooms and offices
  • Clinical areas like exam and reprocessing rooms.
  • Surgical areas that are used for invasive procedures.
• Cleaning involves the removal of foreign material from the surface of an object.
• Disinfection involves a process used to kill microorganisms on inanimate objects and surfaces.
• Cleaning must be done prior to disinfection due to removal of gross oil, which can shelter bacteria from the action of the disinfectant or sterilant.