The Role of Cleaning and Sterilization in Infection Prevention CE ONLINE. An Online Continuing Education Activity Sponsored By.

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1 The Role of Cleaning and Sterilization in Infection Prevention CE ONLINE An Online Continuing Education Activity Sponsored By Funds Provided By

2 Welcome to The Role of Cleaning and Sterilization in Infection Prevention (An Online Continuing Education Activity) CONTINUING EDUCATION INSTRUCTIONS This educational activity is being offered online and may be completed at any time. Steps for Successful Course Completion To earn continuing education credit, the participant must complete the following steps: 1. Read the overview and objectives to ensure consistency with your own learning needs and objectives. At the end of the activity, you will be assessed on the attainment of each objective. 2. Review the content of the activity, paying particular attention to those areas that reflect the objectives. 3. Complete the Test Questions. Missed questions will offer the opportunity to reread the question and answer choices. You may also revisit relevant content. 4. For additional information on an issue or topic, consult the references. 5. To receive credit for this activity complete the evaluation and registration form. 6. A certificate of completion will be available for you to print at the conclusion. Pfiedler Enterprises will maintain a record of your continuing education credits and provide verification, if necessary, for 7 years. Requests for certificates must be submitted in writing by the learner. If you have any questions, please call: CONTACT INFORMATION: 2015 All rights reserved Pfiedler Enterprises, 2101 S. Blackhawk Street, Suite 220, Aurora, Colorado Phone: Fax:

3 Overview The sterile processing of instruments, devices, and items is a significant part of infection control in health care practice. This activity will explore the importance of infection prevention and its impact on patient outcomes. The proper steps and key clinical considerations for instrument cleaning and decontamination will be reviewed. The differences between sterilization and high-level disinfection will be discussed. Different methods of sterilization will be defined and the significance of sterilization monitoring as it impacts patient outcomes will also be included. Finally, current guidelines and recommended practices for proper decontamination and sterilization of these devices will be outlined. LEARNER OBJECTIVES After completing this continuing education activity, the participant should be able to: 1. Explain the importance of infection prevention in patient care. 2. Identify the steps involved with surgical instrument decontamination and cleaning. 3. Define the Spaulding Classification. 4. Describe the difference between sterilization and high-level disinfection. 5. Distinguish the various methods of sterilization. 6. Explain the importance of sterilization monitoring. 7. Identify guidelines and recommendations related to proper decontamination and sterilization of surgical instrumentation. INTENDED AUDIENCE This continuing education activity is intended for perioperative nurses, sterile processing personnel and other health care professionals who want to learn more about sterile processing and the impact on patient outcomes. Credit/Credit Information State Board Approval for Nurses Pfiedler Enterprises is a provider approved by the California Board of Registered Nursing, Provider Number CEP14944, for 2.0 contact hours. Obtaining full credit for this offering depends upon attendance, regardless of circumstances, from beginning to end. Licensees must provide their license numbers for record keeping purposes. The certificate of course completion issued at the conclusion of this course must be retained in the participant s records for at least four (4) years as proof of attendance. 3

4 IAHCSMM The International Association of Healthcare Central Service Materiel Management has approved this educational offering for 2.0 contact hours to participants who successfully complete this program. CBSPD The Certification Board for Sterile Processing and Distribution (CBSPD) has approved this program for 2.0 contact hours. Release and Expiration Date: This continuing education activity was planned and provided in accordance with accreditation criteria. This material was revised in November 2015 and can no longer be used after November 2017 without being updated; therefore, this continuing education activity expires November Disclaimer Pfiedler Enterprises does not endorse or promote any commercial product that may be discussed in this activity Support Funds to support this activity have been provided by Stryker. Authors/Planning Committee/Reviewer Bonnie G. Denholm, DNP, RN, CNOR Program Manager Pfiedler Enterprises Aurora, CO Rose Moss, MN, RN, CNOR Nurse Consultant/Author Moss Enterprises Judith I. Pfister, RN, BSN, MBA Program Manager/Planning Committee Pfiedler Enterprises Julia A. Kneedler, RN, MS, EdD Program Manager/Reviewer Pfiedler Enterprises Westcliffe, CO Aurora, CO Aurora, CO 4

5 DISCLOSURE OF RELATIONSHIPS WITH COMMERCIAL ENTITIES FOR THOSE IN A POSITION TO CONTROL CONTENT FOR THIS ACTIVITY Pfiedler Enterprises has a policy in place for identifying and resolving conflicts of interest for individuals who control content for an educational activity. Information below is provided to the learner, so that a determination can be made if identified external interests or influences pose potential bias in content, recommendations or conclusions. The intent is full disclosure of those in a position to control content, with a goal of objectivity, balance and scientific rigor in the activity. For additional information regarding Pfiedler Enterprises disclosure process, visit our website at: pfiedlerenterprises.com/disclosure Disclosure includes relevant financial relationships with commercial interests related to the subject matter that may be presented in this continuing education activity. Relevant financial relationships are those in any amount, occurring within the past 12 months that create a conflict of interest. A commercial interest is any entity producing, marketing, reselling, or distributing health care goods or services consumed by, or used on, patients. Activity Planning Committee/Authors/Reviewers: Bonnie G. Denholm, DNP, RN, CNOR No conflict of interest Rose Moss, RN, MSN, CNOR No conflict of interest. Judith I. Pfister, RN, BSN, MBA No conflict of interest. Julia A. Kneedler, RN, MS, EdD No conflict of interest. PRIVACY AND CONFIDENTIALITY POLICY Pfiedler Enterprises is committed to protecting your privacy and following industry best practices and regulations regarding continuing education. The information we collect is never shared for commercial purposes with any other organization. Our privacy and confidentiality policy is covered at our website, and is effective on March 27, To directly access more information on our Privacy and Confidentiality Policy, type the following URL address into your browser: In addition to this privacy statement, this Website is compliant with the guidelines for internetbased continuing education programs. The privacy policy of this website is strictly enforced. 5

6 CONTACT INFORMATION If site users have any questions or suggestions regarding our privacy policy, please contact us at: Phone: Postal Address: 2101 S. Blackhawk Street, Suite 220 Aurora, Colorado Website URL: 6

7 INTRODUCTION Registered nurses and other health care workers are continually challenged in today s rapidly changing health care environment with newly recognized pathogens and other well-known microorganisms that have become increasingly resistant to current therapeutic modalities. Infection prevention professionals apply findings from health care epidemiology to prevent the spread of infections within the health care setting. Epidemiology is the study of a disease s population, prevalence, distribution, and determining factors. Epidemiology examines epidemic (excess) and endemic (always present) diseases. Epidemiology is based on the observation that most diseases do not occur randomly, but are related to environmental and personal characteristics that vary by time, place, and subgroups of the population. Hippocrates is generally said to be the father of epidemiology. He is the first person known to have examined the relationship between the occurrence of disease and environmental influences. Infection prevention professionals concern themselves with both prevention (hand hygiene/hand washing, cleaning/disinfection/sterilization, vaccination, surveillance) and with the investigation and management of demonstrated or suspected spread of infection within a particular health care setting. The common title within health care facilities, Infection Prevention and Control, has been adopted for this reason to shift the focus from controlling infections to preventing infections. It is important that health care practitioners understand the importance of cleaning, disinfection, and sterilization as these apply to everyday infection prevention practices, health care personnel, patients, and positive patient outcomes. HEALTHCARE-ASSOCIATED INFECTIONS (HAIs) In October 2008, five leading health care organizations came together to publish practical, science-based strategies to help prevent the six most important health careassociated infections (HAIs). The Compendium of Strategies to Prevent Healthcare- Associated Infections in Acute Care Hospitals was produced by 1 : The Society for Healthcare Epidemiology of America (SHEA); The Infectious Disease Society of America (IDSA); The American Hospital Association (AHA); The Association for Professionals in Infection Control and Epidemiology (APIC); and The Joint Commission. The document states that preventing HAIs is one of the nation s highest goals for priority public health and patient safety. The Office of Disease Prevention and Health Promotion estimates that about 1 out of every 25 inpatients in the US has an infection related to hospital care. These infections lead to an extensive number of deaths and cost the health care system billions of dollars each year. 2 Hospital infections cost Americans between $5.7 billion and $6.8 billion annually in extra health care costs. 3 Surgical Site Infection (SSI) occurs in 2-5% of patients undergoing inpatient surgery in the US 4 with an estimated 290,500 occurring annually. 5 Overall, SSIs are associated with 7

8 about $3.5 billion to $10 billion in annual health care expenditures in the US. 6 Health care professionals must have the expertise and knowledge to provide patients a safe environment with regard to the cleaning, disinfection, and processing of equipment and instrumentation within their practice setting to prevent adverse patient outcomes. DECONTAMINATION AND CLEANING OF SURGICAL INSTRUMENTATION Surgical instrumentation can be used and processed numerous times during the course of a busy day. Many standards and guidelines have been developed and approved by various professional organizations to assist facilities in proper decontamination of surgical instruments for terminal disinfection or sterilization. Ensuring that all instruments are properly decontaminated, cleaned, and prepared for use is critical for any surgical department in promoting safe patient care. Processing starts with the initial use in the operating room (OR) during a case, then involves disassembly, decontamination and cleaning, re-assembly, packaging, and high-level disinfection or sterilization. Immediately after the completion of a surgical procedure, instrument decontamination is performed in a designated area. Surgical instruments and equipment can become damaged if saline, blood, and body fluids are left to dry in or on them. Moreover, dried blood and other organic debris are often difficult, if not impossible, to remove from all instrument surfaces during decontamination. If dried blood and debris are not removed from all surfaces during the decontamination process, subsequent disinfection or sterilization may not be achieved, which could potentially be an avenue for infectious disease transmission. 7 The efficacy of a terminal sterilization or disinfection process depends upon lowering or limiting the amount of bioburden on the item to be processed; therefore, items to be processed should be precleaned to reduce the bioburden to the lowest possible level. 8 As such, decontamination is the first and most important step in the process of preparing an instrument for reuse. The scrub person can facilitate the decontamination process by keeping instruments free of gross soil during a procedure by wiping the surfaces and flushing the channels, ports, crevices and other movable parts of endoscopic and powered instrumentation as needed with sterile water, not saline. All instruments that were opened on the sterile field during a surgical procedure, whether or not they were used, are considered contaminated and therefore need to be decontaminated before processing to the required level of safety for subsequent patient care use. Presoaking Presoaking surgical instruments is performed to prevent blood and debris from drying on them or to soften and remove dried blood and debris. 9 An instrument cleaner, as specified in the instrument or device manufacturer s written recommendations, should be used for all instruments before transport to the designated decontamination area. 10 Treating instruments and equipment with an appropriate cleaner at the point of use can facilitate both the efficacy and efficiency of the cleaning process. Dried blood and debris 8

9 in or on surgical instrumentation and equipment can lead to corrosion, rust, and pitting, as well as obstruction of cannulas and lumens. For short immersion periods, instruments may be presoaked in the following solutions to make further processing more efficient 11 : a near-neutral, low-sudsing detergent that is diluted and used according to the manufacturer s instructions and compatible with the local water supply; or an enzymatic agent, diluted and used according to the manufacturer s instructions; clean, plain, demineralized distilled water. Chlorine bleach (sodium hypochlorite) is used to presoak instruments in cases of suspected or potential transmissible spongiform encephalopathy. Because this solution is corrosive, the instruments should not be soaked in a chlorine solution for more than one hour and should not be autoclaved due to formation of toxic chlorine gas. Alternative preparations include phenolic, guanidine thiocyanate, or sodium hydroxide solutions; however, these chemicals are extremely corrosive and should not be used on endoscopes. Contaminated instruments must be contained during transport and should be transported in a timely manner to a location designed for decontamination. Proper containment of contaminated instruments reduces the potential for injury to personnel or their exposure to infectious organisms; it also prevents damage to the instruments during transport. 12 The Occupational Safety and Health Administration s (OSHA) bloodborne pathogen standard requires that during transport to the decontamination area, contaminated instruments must be contained in a leak-proof container to minimize the risk of exposing personnel or patients to bloodborne pathogens and other potentially infectious organisms. 13 Instruments should be decontaminated in an area that is physically separated (eg, with a door or a wall with a pass-through window) from locations where clean activities are performed to minimize the risk of cross-contamination. For example, cross-contamination can result when soiled items are placed in close proximity to clean items or placed on surfaces upon which clean items are later placed. In addition, aerosols created during cleaning can also cause cross-contamination. Instruments should not be decontaminated in scrub or hand sinks, as these are used for clean activities (eg, hand washing, surgical hand antisepsis). 14 Personnel handling contaminated instruments and equipment must wear appropriate personal protective equipment (PPE) and should be vaccinated against the hepatitis B virus. 15 Personal protective equipment helps to protect the employee from exposure to bloodborne pathogens and other potentially infectious materials. The appropriate PPE for these types of exposures include, but are not limited to, a fluid-resistant gown, heavyduty gloves, a mask, and face protection. In addition, the following activities also apply. Hands must be washed after removing PPE, as perforations can occur in gloves, and hands can become contaminated while removing PPE. 9

10 Reusable protective attire must be decontaminated and the integrity of the attire confirmed between uses. Two pairs of gloves should be worn when cleaning instruments and equipment, if there is a risk for perforation of the outer glove. Exposures to bloodborne pathogens should be reported immediately through the approved health care organization channels. Decontamination 16,17,18 The efficacy of any terminal sterilization or disinfection process depends upon appropriate cleaning to lower or limit the amount of bioburden on the item to be processed to the lowest possible level. Therefore, the first and most important step in decontamination of all reusable instruments and devices is thorough cleaning followed by rinsing. Figure 1 Decontamination Effective cleaning, which primarily removes rather than kills microorganisms, is a multistep process that depends upon several interdependent factors, such as the water quality; the type, quality, and concentration of the detergent or cleaner used; an acceptable washing method; proper rinsing, drying, and preparation of the items to be processed by cleaning equipment; the time and temperature parameters and load capacity of the equipment; and operator performance. Decontamination combines manual or mechanical cleaning with a chemical or physical microbicidal process. Specific cleaning and decontamination considerations for standard, endoscopic, and powered surgical instruments are briefly outlined below. Standard Surgical Instruments Upon arrival in the decontamination area, contaminated surgical instruments and equipment should be removed from the transport containers, sorted, and prepared for cleaning. All instruments and other items that are composed of more than one part or piece should be disassembled to expose all surfaces to the cleaning process. The device manufacturers written instructions for use (IFU) for proper disassembly and reassembly of all processed items should be included in the procedure manual for the decontamination area and consistently followed. 19 Processing personnel should take care to ensure that all small parts, such as screws, nuts, or washers are contained and not lost. Noninterchangeable components of instruments or accessories (eg, parts of a metal 10

11 stopcock) should be kept together to ensure correct reassembly. Procedures to ensure that processing personnel do not place their hands into the container to retrieve reusable sharps that might be hazardous and contaminated with blood or other potentially infectious material should also be developed. The mechanical cleaning process is the safest method for cleaning and provides an effective cleaning process. 20 This method is commonly used in hospitals or very large dental clinics. Contaminated instruments are placed in cassettes or baskets. Then they are run through the unit s cycle of cleaning, rinsing, and disinfection at temperatures high enough to provide at least a high-level of disinfection. This results in a no touch system in which the potential for injury during instrument processing is greatly reduced. The mechanical cleaning process generally entails the following steps. Gross removal of soil. Arrangement of devices in washer basket to prevent contact between the devices and assist in water drainage. Washer disinfector cycle: Pre-rinse for 2 minutes with cold tap water. Detergent wash 2 minutes with hot tap water. Detergent wash 2 minutes with hot tap water (60 C set point). Rinse for 2 minutes with hot tap water (60 C set point). Dry for 15 minutes at 115 C. Visual inspection of devices. If any visible debris is observed on the products during inspection, the cleaning must be repeated. Figure 2 Quality of Water The type of water available for cleaning should be consistent with the manufacturer s written instructions and intended use of the equipment and cleaning agent. Water quality is affected by several factors including conductivity; the presence of dissolved mineral solids, chlorides, and other impurities; and its acidity or alkalinity. Water quality also fluctuates over time. 21 The optimum combination of chemicals used in a washer decontaminator is based on the hardness of the available water. Potable water should be used for either manual or automated decontamination methods unless contraindicated by instrument manufacturers instructions; softened or deionized water should be used for the final rinse. When manually cleaning, instruments should be washed in a manner that provides proper decontamination. Although mechanical cleaning methods are preferred, some delicate instruments may be damaged in a mechanical cleaning process and may require manual cleaning. Manual cleaning should be 11

12 accomplished by submerging the instrument in warm water with an appropriate detergent followed by complete submersion of the instrument in a rinse solution to minimize aerosolization of contaminants. Aerosolization of contaminants, splashing of infectious material, and injury from sharp objects are possible when manual cleaning is performed under a stream of running tap water. 22 Endoscopes and Endoscopic Instrumentation 23,24 Immersible equipment is cleaned or flushed with a detergent recommended by the manufacturer; this loosens organic material and makes it easier to remove. For endoscopes and related instrumentation, use of the appropriate cleaning agent is vital. Detergents consist of various formulations which may include ph builders, buffers, and surfactants that result in the chemical composition that cleans the devices. The amount of cleaning power is determined by the ph of the formulation. For example, a detergent with a very low ph can cause staining and pitting on the surfaces of stainless steel instruments because they are more susceptible to damage due to prolonged exposure to acidic solutions. Combining detergents with the mechanical or automatic force of a cleaning spray facilitates the removal of bioburden. A low-sudsing detergent is recommended so that the detergent can be completely removed. Both the detergent and type of device being cleaned must be considered; certain cleaners are not appropriate for cleaning both endoscopes and endoscopic instruments. Figure 3 Endoscopy Instruments Following the cleaning process, the items must be carefully rinsed and flushed with copious amounts of water. Deionized or demineralized water is often recommended for the final rinse to minimize mineral buildup from tap water. Again, the manufacturer s written instructions for cleaning and processing should always be followed. After the final rinse, the instruments and equipment must be dried. An automatic cleaning device that flushes the ports of endoscopic instruments is an effective and economical method for cleaning reusable channeled instruments and equipment. While these instruments have flush ports, debris can become lodged distally. Some automatic cleaning systems have a mechanism to flush in a retrograde fashion, thereby forcing debris from the larger proximal port. The use of this type of system can also test sealed instruments for seal integrity. Powered Surgical Equipment and Accessories 25,26,27 All powered surgical equipment and accessories should be cleaned according to the manufacturer s written instructions. Attachments, including blades, drill bits, chucks, burr guards, and wrenches, should be removed from powered equipment in the OR by the 12

13 scrub person at the end of the procedure. These attachments are all metal and retain a great deal of blood and debris. Organic debris that remains on powered equipment impedes the sterilization process and can also interfere with its proper functioning. If debris is not removed during the procedure and subsequent transport, biofilm will build within the complex lumens, movable parts, and intricate internal components. If the powered instruments cannot be submerged in an enzymatic solution, the scrub person should spray with a non-enzymatic foam and cover them with a wet towel until the decontamination process can begin. Transportation to the decontamination area should be immediate and should take place in a manner to prevent exposure of patients and personnel to infectious organisms. During decontamination in the sterile processing area, powered surgical equipment and accessories that are composed of more than one piece should be opened, disassembled, and arranged in an orderly fashion. Disassembling and opening of instruments and equipment followed by their proper arrangement minimizes the risk of instrument displacement and improves the efficiency of reprocessing. Sterile processing personnel should be aware of powered surgical instruments that should not be immersed or placed under running water, in ultrasonic cleaners, washer disinfectors, or washer sterilizers as specified by the manufacturer; permanent damage may result if fluid enters the internal mechanisms of the device. The surface of the instrument should be wiped with a mild detergent, using caution to prevent the solution from entering the internal mechanism. As specified by the manufacturer, sterile processing personnel may be directed to: use a neutral or mild alkaline ph cleaning solution to thoroughly cover all surfaces; use a stiff, non-metallic brush, paying attention to crevices and hard-to-reach areas such as seams, joints, triggers, and connectors; use a bottle brush to clean cannula; rinse the instrument to remove all cleaning solution (as confirmed with the manufacturer that running water can be used); repeat the manual washing process until all debris is removed; and dry thoroughly. The detergent is wiped off with a damp cloth and the mechanism is dried with a lint-free towel. Air hoses should remain attached when cleaning pneumatic handpieces, keeping the internal parts of the handpiece dry during cleaning. The air hose and electrical cord should be wiped with detergent, a damp cloth, and dry towel. The accessories are disassembled for cleaning. Figure 4 Powered Equipment 13

14 INSPECTION, LUBRICATION, PACKAGING, ASSEMBLING Inspection 28 Inspection of the instruments and equipment for cleanliness and proper working order is the step following decontamination and cleaning. Inspecting instruments and equipment for sterilization before assembly of trays provides an opportunity to identify those instruments that require additional cleaning or repair before use. The equipment should be inspected for corrosion, pitting, missing parts, and proper seating of attachments; the instrument should be tested for proper working order prior to sterilization. For powered equipment, air hoses should be inspected for damage or wear before and after decontamination and before use. The inspection should be sure that all traces of detergent or germicide and excess fluids have been wiped from the surface of the air hose; batteries and power cords are not damaged, cracked, or worn; and the surface of hoses and cords are clear of debris and traces of cleaning solutions. Instruments can become damaged during use or decontamination. Sterilization may not occur in the presence of soil or water. Instruments should be thoroughly dried to help prevent rust formation during instrument storage. Furthermore, the presence of moisture can impede various sterilization processes. For example, moisture on instrument surfaces alters the moisture content of steam and can pose a challenge for effective heating of the instrument. Ethylene Oxide (ETO) combines with water and creates ethylene glycol (ie, antifreeze), which is toxic and is not removed during aeration. Excess moisture also inhibits the hydrogen peroxide plasma sterilization process and can result in an aborted cycle. 29 Surgical instruments should be inspected for cleanliness and proper working order after decontamination, prior to assembly of trays, in order to identify those instruments that require additional cleaning or repair before use. Instruments should be inspected for: cleanliness; alignment; corrosion, pitting, burrs, nicks, and cracks; sharpness of cutting edges; loose set pins; wear and chipping of inserts and plated surfaces; missing parts; any other defects; removal of moisture; and proper functioning. Upon inspection, any instrument or device found to be in disrepair should be tagged or labeled and removed from service until it is repaired. Identification of defective instruments facilitates segregation of these instruments from those to be used when assembling sets and prevents defective instruments from being used on patients. 14

15 Lubrication The instrument manufacturer s written instructions should be followed for selection and appropriate use of lubricants, which reduce friction between working surfaces; however, some instruments do not require lubrication. Cleaning, in particular ultrasonic cleaning, removes lubricants from instruments. Instruments should be clean before the lubricant is applied, since applying lubricants to soiled instruments can compound the problem of stiff joints and inhibit smooth movement. Lubricants should be compatible with the method of sterilization to be used. 30 Powered equipment should be lubricated with a product specifically recommended by the manufacturer and applied according to manufacturer s instructions. 31 Powered equipment and attachments may need some type of lubricant to decrease friction between working parts, which is essential for optimal functioning of the instrument and helps to prolong equipment life. Some powered instruments are sealed and do not require lubrication, while others may need lubrication to have a longer life span. Manufacturers instructions vary, so it is important to make sure the maintenance recommendations are scrutinized and closely followed. 32 Manufacturers may recommend oil-based or nonoil-based lubricant for powered equipment. Water-soluble lubricants allow steam penetration during sterilization; however, oil-based products cannot be penetrated and thus prevent the sterilant from contacting the instrument s surface. Assembling Cleaned surgical instruments should be organized for packaging in a manner to allow the sterilant to contact all exposed surfaces. Proper organization and adequate drying facilitate contact of the sterilant on all instrument surfaces. Instruments should be placed in a container tray or basket that is large enough to evenly distribute the metal mass in a single layer. 33 Packaging Only validated containment devices should be used to organize or segregate instruments within sets. 34 Many devices used to organize or segregate instruments within sets have not been validated as safe and effective by container or wrap/pouch manufacturers. The presence of these devices inside of a packaged instrument set can prohibit: air removal, sterilant contact with instruments in close proximity to the containment device, sterilant evacuation, and condensate drainage and drying. For example, rubber bands should not be used to keep several instruments together because the sterilant cannot contact surfaces beneath rubber bands and instruments may not be sterilized. Paper-plastic peel pouches should not be used to organize or segregate instruments within sets unless their use is validated by the containment device manufacturer. Small accessory baskets or boxes with lids or covers to contain instruments, parts, or accessories should not be incorporated into sets unless their use is validated by the containment device manufacturer. 15

16 Also, nonabsorbent, nonwoven disposable wrap material (eg, polyolefin spunbound) should not be used as a tray liner or to organize or segregate a small group of instruments to be placed into the instrument set. This type of material is not intended for use within an instrument set that is to be steam-sterilized because it does not absorb moisture. Moisture can pool on this material, causing a wet pack. Secure, protective packaging is best for powered instruments. For example, rigid sterilization containers offer ease of handling and maximum protection. The manufacturer s technical data for types of devices validated for use inside the container (eg, power equipment, items with lumens) should be obtained and special instructions for sterilization followed. 35 Figure 5 Packaging for Sterilization STERILIZATION VERSUS DISINFECTION Since the cleaning process is not microbicidal, a subsequent sterilization or high-level disinfection (HLD) process is necessary to ensure that an item is safe for patient care use. 36 Spaulding Classification System Potentially pathogenic (disease producing) microorganisms are everywhere in our daily lives. Health care practitioners must be aware that pathogenic microorganisms are prevalent in health care facilities due to the large number of patients with transmittable diseases and any patient is a potential host in acquiring a disease or infection. To accomplish successful transmission from an environmental source, all of these requirements for the chain of infection must be present. The absence of any one element will prevent transmission. The pathogenic microorganism must overcome environmental stresses to retain viability, virulence, and the capability to initiate infection in the host. The transmission of infection involves a chain of events that includes: presence of a pathogenic agent; reservoir; portal of exit; transmission; portal of entry; and host susceptibility. Prevention of disease transmission occurs when there is a break in the chain of transmission. How equipment and instruments are cleaned, disinfected, and sterilized can provide a break in this chain by eliminating the presence of pathogenic organisms. The Spaulding Classification system was proposed in 1972 by Dr. Earle Spaulding and classifies equipment and instruments for disinfection and sterilization based on the risk of infection for the patient. 37,38 This classification system has withstood the passage of time 16

17 and continues to be used today to determine the correct method for preparing equipment and instruments for patient use. Items to be sterilized or disinfected have been classified as critical, semi-critical, and non-critical, based on the risk of infection for the patient. According to the Spaulding system, the requirements for sterilization or disinfection are based on the nature of the device or instrument and the manner in which it is to be used as represented by the following three categories. Critical Critical items are instruments or devices that are introduced directly into the bloodstream or other normally sterile areas of the body. These items require sterilization. Critical items include surgical instruments, certain types of catheters, needles, and implants. Semi-critical Semi-critical items are instruments or devices that come in contact with intact mucous membranes but do not ordinarily penetrate the blood barrier. These items may be either sterilized or high-level disinfected. Semi-critical items include noninvasive flexible and rigid fiber optic endoscopes, endotracheal tubes, and anesthesia breathing circuits. Non-critical Non-critical items are instruments or devices that do not ordinarily touch the patient or touch only intact skin. These items can be cleaned and then disinfected with an intermediate level disinfectant, sanitized with a low level disinfectant, or cleaned with soap and water. Non-critical items include blood pressure cuffs, bedpans, linens, furniture, floors, and other medical accessories. Disinfection 39,40 Disinfection is generally a less lethal process than sterilization. Disinfection is the process of killing some, but not necessarily all, microbial life (eg, bacterial spores) on an item or surface. Disinfection is a procedure that reduces the level of microbial contamination, but there is a broad range of activity that extends from sterility to a minimal reduction in the number of microbial contaminants. Chemical disinfection and particularly high-level disinfection differs from chemical sterilization by its lack of sporicidal ability. Chemical disinfectants vary in their level of effectiveness and are influenced by the: nature and number of contaminating microorganisms, especially bacterial spores; amount of organic matter present, such as soil, blood, and feces; type and condition of the instruments, devices, and materials to be disinfected; concentration, time of exposure, ph, and the required temperature of the chemical disinfectant and water hardness and the presence of surfactants. 17

18 High-level Disinfection High-level disinfection kills vegetative microorganisms and inactivates viruses, but not necessarily a high number of bacterial spores. As high-level disinfectants, they are generally used for short periods of time, but may be capable of sterilization when the contact time is extended. The manufacturer s instructions should be followed to determine the appropriate outcome. These agents are also called chemical germicides and in the US are classified by the Food and Drug Administration (FDA) as sterilant/ disinfectants. Spaulding also classified chemical germicides by activity level. High-level disinfectants commonly used today include: Glutaraldehyde. 41 Glutaraldehyde is a saturated dialdehyde that has wide acceptance as both an overall high-level disinfecting agent for semi-critical items and chemical sterilant. Aqueous solutions of glutaraldehyde are acidic and in this state are not sporicidal; therefore, the solution is activated when alkalizing agents are added to make the solution alkaline. With contact times of up to 10 hours, glutaraldehyde is actually a chemical sterilant; however, it is rarely if ever used for sterilization. Depending on the temperature and formulation, glutaraldehyde can achieve HLD in many cases in 10 minutes or less; immersion times of 20 to 45 minutes may be found on some product instructions. During immersion, all surfaces of the item must be in contact with the solution; after immersion, all surfaces of the item must be rinsed thoroughly with sterile water prior to use. Glutaraldehyde is associated with certain hazards for the staff, which must be considered in its selection and use. Vapor generated from glutaraldehyde may be irritating to the respiratory tract; therefore, it should be used in well- ventilated areas or in free-standing or vented chemical fume hoods. The American Conference of Governmental Industrial Hygienists (ACGIH) recommends a maximum limit of 0.05 parts per million for occupation exposure to glutaraldehyde vapors; OSHA has not established occupational exposure limits for glutaraldehyde but has recommended that facilities follow the ACGIH limits. 42 Ortho-phthalaldehyde (OPA). 43 Ortho-phthalaldehyde, a 0.55% solution in an aqueous buffer with a ph of 7.5, is considered a high-level disinfectant. At room temperature, this solution is tuberculocidal at a minimum exposure time of 12 minutes. OPA can be used for most applications in which glutaraldehyde is used and has broad materials compatibility. In addition, it has certain potential advantages over glutaraldehyde, such as excellent stability over a wide ph range, it is odorless, and it is not known to be an irritant to the eyes or nasal passages. 18

19 Intermediate-level Disinfection Intermediate-level disinfection kills vegetative microorganisms, including Mycobacterium tuberculosis, most fungi, and inactivates most viruses. These chemical germicides often correspond to the Environmental Protection Agency (EPA) approved hospital disinfectants that are also tuberculocidal. Low-level Disinfection Low-level disinfection kills most vegetative bacteria except M. tuberculosis, some fungi and inactivates some viruses. The EPA approves these chemical germicides in the US as hospital disinfectants or sanitizers. Sterilization 44,45,46 Sterilization is defined as the complete elimination or destruction of all forms of microbial life. A sterilization process is one that kills all microorganisms, including a high number of bacterial spores. Sterilization processes that are used in the health care environment include steam, ethylene oxide (EO), low-temperature hydrogen peroxide gas plasma, peracetic acid, ozone, and dry heat. The term sterile is measured as the probability of sterility for any instrument, device, or other item; this probability is known as Sterility Assurance Level (SAL). The likelihood that an instrument, device, or item is free of microorganisms is expressed in terms of the probability of a microorganism surviving the sterilization process. Sterility Assurance Levels can be used to describe the microbial population that was destroyed by the sterilization process. Each log reduction 10-1 represents a 90% reduction in microbial population. So if a 6 log reduction is achieved (10-6 ) it will reduce a million organisms to very close to zero. Generally, in the health care environment, a SAL of 10-6 is an acceptable SAL meaning that there is one chance in one million that an instrument, device or item is contaminated or unsterile. Several factors affect the success of the sterilization process, including the following. The sterilizer or sterilizing system must be properly designed and achieve the correct combination of temperature, pressure, and sterilant concentration. The bioburden (the number of microorganisms on the instrument, device, or item) must be low enough to ensure the effectiveness of the sterilization process. The instrument, device, or item must be as clean as possible, therefore reducing the bioburden to as low as possible, before sterilization is attempted. There must be adequate contact of the sterilant for a sufficient amount of time, and the packaging and loading of instruments, devices, and items must allow for the sufficient contact of the sterilant. 19

20 METHODS OF STERILIZATION 47,48 Steam Sterilization Saturated steam under pressure is the preferred sterilization method. Steam sterilization is the oldest, safest, most economical and reliable method of sterilization available in the health care environment. Steam sterilization should be used to sterilize heat- and moisture-stable instruments, devices, and items unless otherwise indicated by the sterilizer or instrument, device, or item manufacturer. Steam sterilization is dependent upon steam pressure, exposure time, drying time, and steam quality. Cycle parameters recommended by the device manufacturer should be reconciled with the sterilizer manufacturer s written instructions for the specific sterilization cycle and load configuration. In addition, certain types of equipment and implants (eg, some pneumatically powered instruments) may require prolonged exposure times or drying times. Following steam sterilization, the contents of the sterilizer should be removed from the chamber and left untouched for a period of 30 minutes to two hours, depending on the load content. Figure 6 Sterilization Manufacturers written instructions for operating steam sterilizers should be followed because steam sterilizers vary in design and performance characteristics. A variety of steam sterilization cycles are used in health care organizations. The practitioner should be informed regarding the differences and performance of the following: gravity-displacement cycles, dynamic air-removal (ie, prevacuum), and immediate use steam sterilization and express cycles. Recommendations from the sterilizer manufacturer may need to be reconciled with the instrument, device, or item manufacturer regarding specific instructions for specific sterilization cycle times and load configuration. Certain instruments, devices, and items may require prolonged exposure times and drying times. Once the steam sterilization cycle is complete, the load should be removed from the sterilizer and left untouched until adequate cool down and drying has been achieved. Immediate use steam sterilization of instruments, devices, and items should be used only in selected clinical circumstances where sterilization by the preferred wrapped method is not possible. Immediate use steam sterilization should not be used as a substitute for insufficient inventory. Immediate use steam sterilization is not recommended due to the increase risk of infection to the patient. This results from the tendency to eliminate one or more of the essential steps in the cleaning and sterilization process due to the pressure of time constraints to deliver a sterile product. The cycle time must be correct for the instrument, device, or item. Disassembly and thorough cleaning must be performed; 20

21 instruments, devices, or items must be used immediately and not stored. In addition, transfer to the sterile field must occur without risk of contamination. Ethylene Oxide (ETO) Ethylene oxide is an effective alkylating agent making it a good sterilant against a wide range of microorganisms. Ethylene oxide is non-corrosive and non-damaging to a wide variety of heat-labile and moisture-sensitive items (eg, lensed instruments, electrical devices) when indicated by the manufacturer. Although an effective sterilant, ETO must be used with care due to its known toxicity and the fact that it is a known carcinogen and may contribute to adverse reproductive effects. It is also highly explosive and very flammable in the presence of air and is usually diluted with inert gases. Factors that affect sterilization with ETO include: time of exposure, gas concentration, temperature and humidity, ease of penetrating the items to be sterilized, and type of microorganism to be destroyed. Instruments, devices, and items must be thoroughly dried to prevent the formation of ethylene glycol (ie, antifreeze) during the sterilization cycle. The manufacturer of any instrument, device, or item should provide written instructions for compatibility with ETO before sterilization. Instruments, devices, and items sterilized in ETO must be aerated to make them safe to handle by personnel and for patient use. Any ETO residual that is absorbed into these items may pose a hazard to both personnel and patients. Any instrument, device, or item that is not sufficiently aerated may cause personnel or patient injury. Exposure to ETO can cause skin irritation, burns of body tissue, and hemolysis. Adequate aeration times reduce ETO vapors and residue to a level safe for both personnel and patients. Instruments, devices and items that are removed prematurely from an aeration cycle cannot be rinsed to remove ETO and may create a hazardous by-product. Long sterilization exposure times and aeration periods make ETO a lengthy sterilization process that can add additional costs for processing. All instruments, devices, and items should first be evaluated for steam sterilization before being placed in ETO. Personnel who have the potential for ETO exposure should wear monitoring devices that meet the National Institute for Occupational Safety and Health (NIOSH) standards. Low-temperature Hydrogen Peroxide Gas Plasma Low-temperature hydrogen peroxide gas plasma is an oxidizing sterilization process that uses hydrogen peroxide as a precursor which is then vaporized. Radiofrequency energy is then used to create an electromagnetic field to excite the precursor. Hydrogen peroxide vapor kills microorganisms. The hydrogen peroxide vapor is then charged with radiofrequency, and the plasma that is created removes hydrogen peroxide from the sterilized instruments, devices, and items. The by-products of this sterilization process are oxygen and water (in the form of humidity). The sterilized items are dry at the end of 21

22 the completed cycle and aeration is not required because there are no toxic by-products. Contact with hydrogen peroxide may cause irritation, but is considered to be noncarcinogenic and non-mutagenic. Factors that affect sterilization with gas plasma include: the appropriate type of packaging materials; cellulosic-based products such as paper and linen are not recommended; lumen restrictions on certain instruments, devices and items that may apply; instruments, devices, and items being thoroughly dry at the time of packaging; trays and container systems being approved for the sterilization process; and varied sterilization cycle times due to the contents of the sterilizer load. Liquid Peracetic Acid Sterilization Systems Liquid peracetic acid sterilant systems are used for instrumentation and other devices that are immersible, heat sensitive, and have been validated by the manufacturer for use in these systems; it is used for items that cannot be sterilized with terminal sterilization processes. This is a just-in-time sterilization process which means at the conclusion if the cycle, the items processed are wet, not containerized, and cannot be stored for later use. Therefore, items processed in these systems should be taken directly to the point of use and used immediately. Ozone Ozone is an oxidizing sterilization process and is a low-temperature sterilization method. Ozone is generated within a sterilizer using water and oxygen; upon completion of the sterilization cycle, ozone is then exhausted through a catalytic converter, where it is changed back in to the raw materials of water and oxygen (ie, non-toxic by-products); therefore, there is no need for aeration. The manufacturer s written instructions for use of an ozone sterilizer should be followed; in addition, written documentation of the acceptability of ozone sterilization from the device or sterilizer manufacturer s list of validated devices should be obtained. Figure 7 Oxidizing Process Factors that affect ozone sterilization include the following. Selection of appropriate packaging materials; cellulosic-based packaging materials such a paper and linen are not recommended. Lumen restrictions on certain instruments, devices, and items may apply. Items should be placed in the chamber as specified in the sterilizer manufacturer s instructions for use. 22

23 Dry Heat Sterilization Dry heat sterilization is generally used only for specialized purposes in most health care facilities (ie, for items and materials that are impenetrable to moist heat). This method may be used to sterilize waterless items that can withstand high temperatures and when indicated by the manufacturer. Figure 8 Dry Heat Sterilization STERILIZATION MONITORING Many variables affect the achievement of sterility, therefore monitoring the sterilization process is essential. Mechanical, chemical, and biological monitoring methods are used to assist in identifying and preventing sterilizer malfunctions and operational errors made by personnel. 49 Mechanical monitoring devices provide real-time assessment of sterilizer cycle conditions and permanent records by means of either a chart recording or computer printout. The operator can physically assess time, temperature, pressure, printouts, and gauges as a means to verify that all cycle parameters have been met. This also allows for a physical assessment to warn if a sterilizer failure may have occurred. Chemical monitoring in the form of a sterilization chemical indicator should be used inside and outside of each package and load sterilized. External chemical indicators are used on the outside of packages and are often used as packaging closures such as sterilizer indicator tape. The purpose of the external chemical indicator is to differentiate between processed and unprocessed items. An internal chemical indicator or integrator should be placed inside packaging to indicate whether the contents have been exposed to one or more of the conditions necessary for sterilization. These should be placed in an area of the package that is believed to be least accessible to sterilant penetration, therefore presenting the greatest challenge. Internal chemical indicators do not establish whether or not an item is sterile, but demonstrate that the contents were exposed to the sterilant. There are a variety of internal chemical indictors available and manufacturers instructions should be reviewed for selection with the appropriate sterilant and outcome. A biological indicator is the most accurate method of monitoring sterilization effectiveness. A biological indicator is commercially prepared with a known population of highly resistant spores that tests the effectiveness of the method of sterilization being used. The biological indicator is used to demonstrate that conditions necessary to achieve sterilization were met during the sterilization cycle. Different sterilization methods require different biological organisms to be used for routine load release, routine sterilizer efficacy monitoring, sterilization qualification testing, and periodic product quality assurance. 23