Cleaning with Multi-Enzymatic Instrument Chemistries for Medical Device Reprocessing
All PIM content was independently developed and reviewed to be vendor-, product-, and service provider-neutral.
Use of multi-enzymatic cleaning solutions improve outcome, save money via greater efficacy and shorter cleaning time, eliminate caustic detergent chemicals and neutralizers, and improve the useful life of surgical instrumentation.
Project Talking Points
- Medical devices and surgical instruments represent a large portion of a medical facility’s spend.
- Reprocessing instructions should always be referenced to keep reusable instruments in good working order.
- Reprocessing of medical devices includes pre-treatment, cleaning, rinsing with high purity water, and drying of devices prior to subsequent sterilization or disinfection. Cleaning is the critical first step when reprocessing surgical devices; thorough cleaning is required before sterilization and high level disinfection can occur.
- Multi-enzymatic cleaners allows for the cleaning of surgical devices to occur rapidly and with less energy.
- Incorrect reprocessing can result in product failure and even in danger to the health and wellbeing of the patient. Improper cleaning of surgical devices can be a vector for Surgical Site Infections (SSIs) and Hospital Acquired Infections (HAIs).
- Removal of infectious agents, organic and inorganic soil, is critical for patient and staff safety.
- Large volumes of cases and pressure to turn around sets quickly have lead to reprocessing concerns, and the need to evaluate cleaners that can provide efficiencies and address needs.
- Enzymatic cleaners were originally designed as pre-cleaners for use in endo/GI labs to remove soil on endoscopes in patients’ rooms.
- In the 1990’s enzymatic cleaners were introduced to facilitate the reprocessing of surgical devices, and to provide a more neutral pH cleaning formulation for instrument preservation.
- Recent studies have shown that enzymatic cleaners may not only remove, but may actually degrade infectious agents.
- When utilizing enzymatic cleaners, several factors must be taken into account including water temperature and quality, contact time, concentration, and pH.
- Some enzymes, including proteases, are more active at higher pH, and some are active at neutral levels.
- Enzymatic detergents consist of a detergent with a neutral pH or low alkaline formulation to which one or more enzymes have been added to surfactants and stabilizing agents.
- Enzymes are catalysts that speed up chemical reactions up to 1,000,000 times.
- Even detergents with the same surfactants and ingredients without enzymes take at least 10 to 15 times more contact time to achieve an acceptable outcome.
- Although most enzymatic detergents are diluted in tap water for cleaning and automated washing, when RO or distilled water is used outcome and reprocessing times are improved. However, it is important to follow manufactures recommendations for dilution rates.
- Rinsing is important after cleaning with enzymatic cleaners to remove adherent soil and residue as enzymes in cleaning detergents keep working until they are washed away.
- PPE should be worn when handling enzymatic cleaners and when processing soiled devices.
- Enzymatic cleaners also clean waste pipes and washing machines, and contribute to the breakdown of contaminants in the waste water stream, as well as the target soiled devices.
- Caustic alkaline detergents release hazardous chemicals into the waste water stream, killing native aquatic species and affecting the sustainability of our planet.
- Traditional caustic alkaline detergents reduce the useful life of medical devices through pitting and corrosion, increasing instrumentation repair and replacement costs.
- Most alkaline cleaners require a neutralizer at an additional expense.
- Multi-enzymatic detergents are by nature biodegradable, and some are safe for aquatic life in waste water stream.
- pH neutral instrument chemistries are non-corrosive to delicate valuable instrumentation, extending the devices’ useful life and reducing repair and replacement costs.
- pH neutral detergents often follow the enzymatic wash step, and provide chelating action and further removal of residue.
- pH neutral detergents are highly recommended for the final wash phase when processing eye instrumentation.
- Enzymes are specific to certain substrates, much[al1] as a lock and key.
- Cocktails of enzymes require stabilizers and coenzymes, as well as certain surfactants, to be effective.
- Some enzymatic solutions may not be properly stabilized so that the protease in solution will attack the other enzymes in the formula.
- Chemical analysis using a spectrophotometer measures enzyme activity.
- Incompatibility or degraded enzymes may be observed when separation is present in the solution; this lessens the efficacy of the detergent.
- Enzymatic cleaners must be stored at room temperature, away from heat source or they will degrade.
- Degrading enzymes have a significant odor. When this is observed, remove and discard the solution.
- Some enzymatic cleaners contain only one enzyme or two enzymes that are the same type, such as two proteases.
- Others have trace amounts of enzymes that may not be detected or have enough activity at use dilution.
- Multi-enzymatic detergents containing more than one type of enzyme will remove more types of soil like blood, fats, starches, and carbohydrates, than single or dual protease cleaners that only address protein.
- Multi-enzymatic cleaners come in ready-to-use and super-concentrated varieties that can work for pre-cleaning, soaking, automated washers, manual cleaning, and for one brand in ready-to-use single use wipes for manual cleaning.
- Liquid multi-enzymatic cleaners can be dosed for concentration unlike solid brick cleaners which melt and cannot be measured.
- Liquid multi-enzymatic cleaners demonstrate significant savings, providing a better ROI than other cleaning chemistries.
- Free-rinsing enzymatic cleaners remove residue on equipment surfaces and on surfaces of medical devices.
Triple Bottom Line Benefits
- Cost benefits: Multi-enzymatic cleaners can be highly effective when reprocessing medical devices, as they can save time, energy, and provide a sizable return on investment. Far less detergent per cleaning cycle is required than detergents without enzymes. Enzymatic cleaners operate at lower temperatures. Thus less energy is required and time to process is drastically reduced due to increased speed of the catalytic reaction. As most enzymatic cleaners are pH neutral or near-neutral, a secondary cleaning agent or neutralizer is not required to neutralize the alkalinity of a caustic solution. In many cases, when enzymatic cleaners are used for pre-cleaning, the required time for subsequent automated cleaning is reduced significantly. The shortened cleaning time increases turnaround times as needed items are made available to the OR faster. Furthermore, the ability to rapidly remove bioburden and organic soil can contribute to the facility’s bottom line, reducing the risk of SSIs due to retained soil and bioburden on surgical instrumentation. When enzymatic cleaners are used, staff productivity increases. Using enzymatic cleaners in sonic washers at correct temperature can greatly improve the process, reducing the need for extended cycles and contributing to a significant reduction in HAIs. When liquid enzymatic cleaning agents are used, dosing can be controlled, residue can be eliminated, and soil dispersed so that it can be rapidly washed away. Most enzymatic cleaners are pH neutral or near-neutral. Neutral pH detergents are by design non-corrosive. As a result, instrumentation has a longer useful life. This creates inventory savings by way of reduced repair and replacement. The benefit of paying more for properly formulated and validated multi-enzymatic cleaners translates to significant cost savings and healthcare benefits.
- Environmental benefits: Liquid multi-enzymatic solutions are safe for people, animals, and the environment in that they disperse harmlessly into the waste water stream with no adverse effects to aquatic species. The active ingredients contain the same proven safe digestive enzymes that are present in our bodies to digest food, including protein, and used in sewage treatment. Because multi-enzymatic cleaners are approximately pH neutral and non-corrosive, there are no caustic chemical residues left behind on cleaned surfaces to interfere with patient and staff safety. Due to the catalytic action, less product may be required. Enzymes reduce noxious odors. The same product used for cleaning surgical devices may be used to remove contaminants from surfaces, the manual soak sink, and reduces the need for hazardous environmental cleaners to follow.
- Social and satisfaction benefits: Multi-enzymatic cleaners can be used for pre-cleaning, soaking, manual cleaning, and automated cleaning, thus reducing the need to control unnecessary inventory of products such as alkaline cleaners and neutralizers. Sterile processing staff will also appreciate the cleaners’ heightened efficacy and catalytic action. The Operating Room will appreciate improved turnaround times for cases. In fact, enzymatic cleaners can improve the social satisfaction of both the OR and Sterile Processing personnel. If the cleaner is applied in the operating room, subsequent cleaning in decontamination will result in less reprocessing time and effort, while increasing Sterile Processing staff’s competencies with a highly effective cleaning agent. This reduces the unnecessary stress on staff to turn around cases without proper processing, and the extra work required to remove dried-on blood and other contaminants. Surgeon satisfaction is increased when instrumentation is preserved and sets arrive in a timely manner for surgery. Damaged instruments or those with rust or corrosion can contribute to Surgical Site Infections (SSIs), granulomas, infection, and even death. Using multi-enzymatic instrument cleaners contributes to safer patient outcome, and staff satisfaction.
- Quality and Outcomes: Properly processed items for patient care can greatly improve surgical outcomes, reduce hospital acquired infections and address facilities quality assurance initiatives. While recent standards have recommended the routine use of cleaning indicators to monitor the efficacy of the process and equipment used for automated cleaning, utilizing validated cleaners and consistently following recommended reprocessing instructions can contribute to improved clinical outcomes. Instrument chemistries vary in concentration, dilution rates, and the quality of the components. The activity of the enzymes at use dilution is critical for removing organic soil. Multiple enzymes can improve patient outcome as they break down a plethora of organic soils including protein, blood, carbohydrates, biofilm, and even infectious agents. Some enzymatic cleaners have been designed for activity at use dilution. Others may have traces of enzymes that, when diluted, show little or no activity at all. It is important to ensure that the products you are using have demonstrated effectiveness. The quality of the components as well as the water used can contribute to best outcome. Water is a universal solvent. High purity water when added to instrument chemistries can facilitate the cleaning process. While multi-enzymatic cleaners are more costly than other detergents, they contribute to positive patient outcome by rapid dispersal of soil, reduce energy consumption, safe to our water supply, and once properly rinsed away provide the safety needed for subsequent sterilization and disinfection.
1. When purchasing instrument chemistries it is important to note that few are sustainable or environmentally preferable. Many instrument chemistries are marketed as “green” or “environmentally friendly” without the proper validations or credentials. Consider products verified by the U.S. Environmental Protection Agency, or Green Seal if available, and only those that have have been tested by a thorough validation regimen. For example, look for EPA’s Design for the Environment (DfE) designation and label when considering candidate cleaners for sustainability and environmental preferability.
2. Consider pH neutral multi-enzymatic detergents as opposed to alkaline detergents. ANSI/AAMI ST 79 has recommendations for the ideal cleaner, and these criteria are in line with environmental goals. Use these as purchasing guidelines when considering cleaners:
• Environmentally friendly
• Nontoxic in specified use dilution
• Provide for rapid soil dispersion or suspension
• May be used in all water types
3. Cost-Benefit Analysis/ROI
• Note that enzymatic detergents do on average cost more than other cleaning agents, and multi-enzymatic detergents with active enzymes at use dilution are priced accordingly based on the concentration. It’s important to consider the benefits and savings that may outweigh the risks associated with caustic cleaners and those with high or low pH that can be corrosive to devices and harmful to the waste water stream.
• Look at volume of product and cost per use, expiration date, and shelf life of the product, as these vary from manufacturer to manufacturer.
• Consider size of packaging in relation to your facility’s needs. Recently several suppliers of instrument chemistries have introduced super-concentrated versions of their cleaners. Some cleaners come in 30 or 55-gallon drums, and others in concentrated formulas in compact 1 or 2.5 gallon containers and provide an equal amount of product at use dilution.
• Be sure to note whether product is sold in gallons vs. liters (1 liter = 0.264 gallon), as these measurements matter in terms of volume and ultimate cost.
• Also note that as enzymes are expensive and have a shelf life under specific storage conditions, there is an advantage to purchasing smaller containers in that higher turnover of small vessels means the enzymes are more likely to stay active for a longer period of time.
• Look at dilution rate. Manufacturers should be able to provide the cost per diluted gallon of product, otherwise known as use dilution. Some manufacturers provide a large use dilution range. When comparing product, utilize the lowest and/or highest dilution rates to calculate actual cost.
• Alternatively, compare the monthly spend of current and future product.
• Solid detergents cannot be measured accordingly.
• To calculate ROI, determine use dilution on the label, and benchmark with machine setting. Then determine the amount of product needed and the volume of water used for each cycle within the machine.
o Avg. 9 gallons (34.07 liters) of water in the automated washer for each cleaning step. Multiply the use dilution cost by the amount of water in the cycle.
o Avg. 4 gallons (15.14 liters) of water used at the soak sink for manual cleaning. Multiply the use dilution cost by the amount of water in the sink.
o Avg. 4 gallons (15.14 liters) of water used in the sonic. Multiply the use dilution cost by the amount of water in the sonic.
o Cart washers have significantly more capacity and may have a reservoir with retained water up to 100 gallons. Multiply the use dilution cost by the amount of water in the cart washer.
o For ready to use products, determine the amount of “squirts” per bottle, and calculate accordingly.
1. Determine stakeholders. Decision making team can include SPD Managers and personnel, OR staff, infection preventionists, Materials Management, Supply Chain, C-suite financial executives, and Sustainability leaders. You should also consult your equipment reps.
2. Understand current conditions and Identify current arrangements for manual cleaning and settings for automated cleaning.
a. How (in what way) and how quickly are your soiled items transported to the decontamination area?
b. How willing is your OR staff to remove gross soil or pre-clean?
c. If surgery is performed in an outpatient facility, where will the reprocessing occur?
i. What pre-cleaning is done at the clinic? Does the clinic do their reprocessing in house? Do they have a sonic or automated washer?
ii. If items are reprocessed in an outside facility, determine what pre-cleaning is required and how products will be transported.
iii. Determine if devices are soaked over the weekend.
d. What is your daily case load and turnaround time?
e. How much of the daily case load is manual versus automated cleaning?
f. Are most sets processed in the sonic before automated cleaning?
g. How are eye instruments processed? (Manual, sonic, or separate automated cycles)
h. How are neuro instruments processed? Are they processed separately from other general sets?
i. Determine the needs of the endo suite/GI lab.
i. How much cleaning is done in patients’ rooms?
ii. Do they have an AER?
j. Determine general condition of the automated washers.
k. Are fast/turbo cycles being used in the automated washer? (These cycles may require significant pre-cleaning in advance.)
l. What products are currently being used for pre-cleaning, soaking, manual cleaning, sonic, automated washers, and cart washers?
m. Can the same product be used for multiple applications?
n. What products are being used in the automated washers for specific cycles?
o. Check your automated washer settings.
i. What is the contact time?
ii. What is the temperature?
iii. What is the dilution rate being drawn?
iv. Note the rinse settings and frequency after wash cycles, as well as the dry time.
3. Determine the types of instrument chemistries to be used and the specific settings recommended by the medical device manufacturer, detergent manufacturer, and the equipment manufacturer.
a. Identify the cleaning steps for which the instrument chemistries would be needed. These include:
iii. Manual Cleaning
v. Automated Washer
vi. Cart Washer
viii. Drying Agent
ix. Descaler/Stainless Steel Reconditioner
x. Acid Neutralizer (if using a high alkaline detergent)
xi. Ink and Adhesive Removal
xiii. High Level Disinfection
b. Determine the type(s) of enzymatic cleaner to be used.
i. Base choice on the type of soil and application. Example) endo, GI lab, eye surgery, orthopedic, general instruments.
ii. Determine cleaning agent based on type of enzyme(s) included in solution. These include: single protease/dual protease/multi-enzymatic cocktail with protease, lipase, cellulase, etc. Note: More types of enzymes mean more kinds of soil are broken down.
iii. Determine whether liquid or solid, and if product is free rinsing.
c. Consider several critical parameters for instrument chemistries to keep in mind:
i. Contact time (Amount of time required for detergent to fulfill cleaning)
ii. Temperature recommended (Note: Warm is better than room temperature for manual cleaning.)
iii. Water quality (What is in your water source? Water hardness changes cleaners’ efficacy)
iv. Cleaning method (Automated or manual? Pressure or friction?)
v. pH of detergent
• Non-corrosive neutral at pH 7 is optimal
• pH >9 or <4 is likely to cause corrosion to surgical devices
vi. Dosing/concentration (How much product is recommended per use? This is a major long term cost driver.)
vii. Environmentally preferred. “Green” claims need to be proven and/or validated. (Note: Only one brand on market is currently awarded U.S. Environmental Protection Agency’s Design for the Environment partnership for safer chemistry for its entire line of instrument chemistries.)
viii. Has the instrument chemistry been validated by an independent agency?
ix. Storage conditions and shelf life
4. Count total number of automated washers and/or sinks in need of cleaner, then chart cost and dilution rates of different brands for accurate comparison of price and efficacy as noted above in Purchasing Considerations (possibly with help/tools from vendor, such as an ROI calculator)
5. Identify possible solutions vendors.
a. Do they provide ready to use and/or concentrated detergent formulations?
b. Do they manufacture their instrument chemistries or do they contract to a third party?
c. Is their primary product line equipment for instrument processing?
d. Is the vendor committed to the sustainability initiative?
e. Have their instrument chemistries been awarded DfE from the U.S. EPA for sustainability and safer chemistry?
f. Are their detergents in liquid or solid form?
g. Are their instrument chemistries validated?
h. Do they provide dosing equipment as well as detergents?
i. Do they provide initial training?
j. Do they provide installation?
k. Do they provide in-services/continuing education?
l. Location of source (International or domestic?)
a. Gather input from OR re: participation for pre-cleaning.
b. Confirm and document how used items are transported.
c. Determine if you are going to use multi-enzymatic cleaners for manual cleaning at sinks and/or in automated washers.
d. Confirm and document how the product will be diluted. Example: proportioner or dispensing system, manual pump, measuring cup or receptacle.
e. Review cleaning steps
i. Rinse off gross soil in cool water <43 degrees C to prevent coagulation of blood.
ii. Soak devices in enzymatic cleaner to begin the breakdown of soil prior to manual or automated cleaning.
iii. Some motorized devices may not be able to be immersed. Review manufacturer’s instructions for powered equipment.
iv. Scrub outer surfaces of device with appropriate implement. Brush external surfaces, crevices, and box locks.
v. Brush interior surface of lumen devices with appropriately sized brush to ensure full width and depth of device are reached.
vi. Rinse thoroughly with warm water. If lumens, be sure to irrigate internal channels.
vii. Wherever applicable, place devices in sonic with enzymatic solution.
viii. Follow with automated wash steps per manufacturer’s recommendations and availability of equipment within department. (Note: Some clinics and surgery centers may only have manual cleaning available or a secondary step with the sonic.)
ix. Rinse thoroughly using high purity RO or distilled water for the final rinse.
1. Use of RO or other high purity water sources can facilitate cleaning of surgical devices. Some facilities are utilizing high purity water for the entire wash cycle when reprocessing surgical devices.
x. Repeat cleaning if visible soil is observed.
f. Implement at sink
i. Install proportioner at sink to automatically administer proper dosing. Alternatively put a line in the sink and use hand pump as standard measurement.
ii. Begin washing devices according to multi-enzymatic cleaner’s recommendations for contact time and temperature.
iii. Personal Protective Equipment (PPE) is crucial when handling contaminated devices and chemical agents.
g. Implement at automated washer or sonic
i. Check settings on machine to conform with new product requirements.
ii. Record existing and new settings.
iii. Switch to new multi-enzymatic cleaning product and cleaners.
iv. Remove any existing product to avoid chemical reaction or incompatibility.
v. Check machine settings on dilution rate, temperature, and contact time,
vi. Adjust settings if necessary with your biomed department or equipment vendor according to multi-enzymatic cleaner’s recommendations for best outcome.
vii. Begin washing devices according to multi-enzymatic cleaner’s recommendations and machine IFUs.
viii. QC automated washer with physical monitors as well as test soil indicators at least once per week, optimally daily before the first shift begins.
h. Inspection after cleaning
i. Inspect devices for visible soil.
ii. Verify cleanliness with test soil indicators to QC machine functionality, first with original cleaning product, then with new multi-enzymatic cleaner and detergents.
iii. Repeat cleaning if device is not visibly clean, and then re-inspect after second cleaning.
- Utilizing validated instrument chemistries with multiple enzymes can address cost savings, as well as environmental concerns.
- Mt. Auburn Hospital, Cambridge, MA. It is a 213 bed facility affiliated with Harvard University. It has comprehensive inpatient services in all medical specialties, providing medical services to several area healthcare facilities. Mt. Auburn switched to pH neutral multi-enzymatic, low foam detergent. After implementation, they found a significant difference in functionality of their devices, maintenance of their anodized aluminum container surfaces, and a reduction in instrument repair and replacement. (testimonial from Mt. Auburn 2013)
- Cape Fear Valley Medical Center, NC. It is a “robust” regional medical center with 200+ beds, a Family Birth Center, and a Level-III Neonatal Intensive Care Unit (NICU). The facility discovered significant corrosion on medical devices prior to switching to pH neutral multi-enzymatic cleaner. Even their device manufacturer commented on how improved the surface of the devices appeared after the product was changed. They appreciated the cost savings as well as the improved turnaround time of sets, and expanded the use from their flagship hospital to other facilities in their network.
The SPD Manager had the following to say regarding the switch to multi-enzymatic cleaners in Cape Fear Valley’s automated washers. “We have used multi-enzymatic solutions for the past 6 years I have been in this department. No problems with them. [Multi-enzymatic cleaners] are less harsh on instruments. The pre-wash/soak with enzymatics save time on rewashing items. [The facility experienced greater efficiency because] the organic material does not dry and set up.” (testimonial from Cape Fear Valley Medical Center, 2013)
- Shands Jacksonville Medical Center, Jacksonville, FL. Shands is a 620 bed general medical and surgical facility and teaching hospital. The hospital was looking at cost savings initiatives when they switched to a highly concentrated, pH neutral, multi-enzymatic cleaner. They found not only the cost savings they were looking for, but also significant improvement in outcome and turnaround times. (testimonial from Shands Jacksonville Medical Center, 2013)
Regulations, Codes and Standards, Policies
- En ISO 13485, international standards, standards http://www.iso.org/iso/catalogue_detail?csnumber=36786
- EN ISO 15883, international standards, standards
- ASTM A 380-06, Standard practice for cleaning, descaling, and passivation of stainless steel parts, equipment, and systems, international standards, standards
- EPA on liquid medical waste, federal regulations, regulations http://www.epa.gov/epawaste/nonhaz/industrial/index.htm
- ANSI/AAMI ST79:2010/A4:2013, Comprehensive Guide to Steam Sterilization and Sterility Assurance in Health Care Facilities, guidelines
- IAHCSMM Central Service Technical Manual, Global Edition, recommendations
- Case Academy “Green Instrument Chemistries” Tutorial, www.casemed.com
- IAHCSMM www.iahcsmm.org
- U.S. Department of Veterans Affairs Green Management Programs (GMP) http://www.green.va.gov/
- Smith & Nephew. Instructions for care, maintenance, cleaning and sterilization of Smith & Nephew orthopaedic devices. 2014.
- Proper Maintenance of Instruments, 10th edition, 2012. Working Group Instrument Reprocessing. Recommendations.
Chemicals, Supply Chain
- Chemical minimization/elimination
- Strategic Operations
- Chemical Reduction
- Central Sterile
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