Advanced Instrument Processing Solutions

Archive for the ‘Cleaning Standards’ Category

What is the difference between Neutral pH Enzymatic Detergents and Alkaline Detergents ?

For years alkaline detergents have been used in the cleaning of organic soils from multiple surfaces and substances. They are used in the food industry for flatware, dishes and pots and pans, for the cleaning of laundry both in the home and large scale commercial laundries, in labs for the cleaning of glassware, in life sciences, for cage cleaning and are a favorite in Europe for surgical instrument cleaning.

Alkaline detergents can vary in pH from mildly alkaline (pH 9.5-10) to highly alkaline (pH12-13). Alkaline detergents work by chemically changing organic soil. Alkali’s hydrolyzing peptide bonds, breaking down large insoluble proteins into smaller more easily soluble polypetides. Alkali also works on fats by the process of saponification, which changes fats into soap and glycerin. Alkaline detergents are best suited for mechanical washers because these washers lack the friction that manual cleaning provides through brushing or the cavitation provided from ultrasonic cleaners. Alkaline detergents are usually less expensive than enzymatic detergents but require a higher wash temperature of around 175°F to work properly.

 So why are we in the US so hesitant to use alkaline detergents to clean surgical instruments? First off is that they are corrosive if not dosed properly. Highly alkaline detergents are caustic and not suitable for all materials, a detergent with the pH of 12 should never be used on anodized aluminum (e.g. rigid containers) because it will begin to break down the anodized coating of the aluminum well within 10 washes. Also unless formulated with the right buffers (e.g. deconex Alka One-x ), high alkaline detergents need to be followed with a correctly dosed acid rinse to neutralize any residuals left on the instruments. If they are not buffered or neutralized properly they will begin to remove the passivation layer from stainless steel and corrode the instruments.

On the other hand we have “neutral” pH detergents and “neutral” pH enzymatic detergents. Both forms of neutral pH detergents have a pH range from 7-8.5. Plain Neutral pH detergents are usually considered to be “gentle detergents”. Those intended for use with surgical instruments will normally contain surfactants, chelating agents and if properly formulated anti-corrosive agents. They contain nothing that chemically changes organic soil, but instead depend on their surfactants to lift and remove organic soil from surfaces. There are a few neutral pH detergents that are formulated not only to clean organic soil, but are also capable of removing the residues of High Level Disinfectant from scopes before switching disinfecting processes from aldehydes to amines or visa-versa (e.g. deconex 36 Intensive-x ).

Neutral pH enzymatic detergents “pack the kick” for chemically changing organic soil by the addition of the enzymes. Enzymes are Bio-Catalytic protein’s, they break large organic molecules into their smaller building blocks.  Unlike alkaline’s which target multiple organic substances at once enzymes are specific to the soil they are breaking down. Protease enzymes break down protein, lipase enzymes break down fats, amylase breaks down carbohydrates. The enzymes in neutral pH enzymatic detergents are produce by bacteria.  Subtilisin a protease enzyme was originally obtained from the growing of the bacteria Bacillus subtilis. Presently numerous bacteria and fungi can be engineered to produce specific enzymes, so enzyme manufacturers are not dependent on just one type of bacteria ( e.g Bacillus subtilis) to produce the enzymes they need. Neutral pH enzymatic detergents require a temperature of between 90°F-140°F to do their work. Low temperatures will make the enzymes sluggish and they will not catalyze their target soil properly and temperatures above their working range will denature them. Also until recently most enzymatic detergents were not as efficacious at removing fibrin from surgical instruments as alkaline detergents. The discovery that cellulase will break down this insoluble protein in dried blood has changed this paradigm. Now multi-enzymatic detergents that contain cellulase (e.g. deconex Power Zyme ) do a comparable job to the cleaning power of alkaline detergents when it comes to fibrin removal.


Lastly it should be mentioned that a combination of multi-enzymatic and mildly alkaline (pH9-10) detergents has shown to harness the ability of both modes of cleaning into a superior cleaning system especially suited for difficult to clean instruments like daVinci endowrist® instruments (e.g. deconex Twin pH10/ Twin Zyme ) These are normally packed in separate containers and dosed into the washer disinfector during the wash phase of cleaning.  In the validation study of the deconex Twin System and the Belimed daVinci load carrier for endowrist instruments not one of the instruments in the study had a proteinaceous soil level “above the alert value of 100μg. In fact if you have a dishwasher at home and use pod packed detergent with separate compartments you are already using a similar system on your dishes. The reason for the separate container/compartments is because if you were to combine the chemistries in one container or “pod” they would “cannibalize” each other, but when combined in “concert” in the washer they support each other to gently remove the toughest of organic soils. The separate packaging of these chemistries has recently been overcome by the scientific staff at Borer Chemie. Their latest  product deconex Prozyme Alka is a multi-enzymatic mildly alkaline detergent all in one container. It has no know material compatibility and is even mild enough for use on anodized aluminum, yet its superior clean power is capable of breaking down the toughest of organic soils like fibrin and biofilms. Like all Borer Chemie products it is extremely environmentally friendly to the point that it contains no EDTA or NTA. These chelating agents are widely used in detergents to “soften water” but pose major environmental threats because they accumulate and remain in water unchanged for long periods of time. 

International Healthcare Central Service/ Sterile Processing Week Oct. 12-19 2014

I want to take this opportunity to wish all my colleagues throughout the World a Happy CSSD/SPD Week!! You are all truly the unsung and forgotten HEROS of Healthcare, without whom a facility cannot function, yet few people know who you are and how important your job is. I know from personal experience that if someone asks me what I do for a living and I tell them I’m a Certified Sterile Processing Technician their eyes glaze over they look around quizzically and then ask “what the heck does that mean?” I think it is high time we make ourselves known. Everybody knows what a Doctors job entails, what a Nurse does and even what X-ray and Respiratory techs do, but how many people know what you do for a living? When I explain to people that a Sterile Processing Tech decontaminates assembles and disinfects, high level disinfects, or sterilizes equipment and instruments according to the modalities needed to make them safe to reuse I am usually told “I thought the nurses and doctors did that” (sigh…yes and pigs can fly). All of us who have ever worked in CSSD/SPD know the answer to that.

Isn’t it time you got the recognition you deserve for the job you do? Be proud of what you do, you are patient safety advocates, let people know that! Tell people what you do and how your adherence to recommended best practice and standards keeps patients safe from HAI’s and SSI’s even though you have no direct patient contact. Celebrate your week with your Team too…Yes You are TEAM…I know the tensions that go on in CSSD/SPD, I have worked all three shifts, unless your department works as a “well oiled machine” one shift helping out the other, you will never garnish the respect your department deserves.

 Above all I urge you all to keep yourselves educated and educate others on what you do and why. Always follow recommended best practices, this is what your facility will be audited on by TJC, AAHC, CMS, etc. If you process items “off label” to get things done quicker for a case, it is not the doctor that will be in question in court if there is litigation due to an SSI, it is you. If someone asks you why things are taking so long, tell them you are following the IFU of the manufacturer on reprocessing. Let those who question you see the IFU of what you are reprocessing, unless they have the capability of changing the laws of physics, you are doing things right. Keep yourself abreast of all the newest technologies in Sterile Processing and what is going on in medicine. We live in an ever changing world. The Sterile Processing Department of today is not what it was 30 years ago, instruments have become exceedingly complex and the pathogens we are fighting have become more drug resistant.  Keep the IFU’s for all the equipment you reprocess current and learn about the pathogens you are fighting (here is a link to the CDC’s 2013 antibiotic resistant threats to get you started, yes it’s pre Ebola and EV-D68 but those both are Viruses which antibiotics have no effect on. )


Above all I want to personally Thank You All for working diligently in the most Important Department in Healthcare!

We have a lot of problems cleaning the soil off of the Bi-polar and Mono-polar surgical instruments at our facility, do you have any suggestions?

The problem of cleaning  eschar off of electrosurgical instruments has been an issue since these instruments first started being used.  As you know these instruments are used to cauterize tissue to minimize the amount of bleeding at the surgical site. This is done by passing an electrical current through the instrument either through opposing tips with different electrical charges or through a mono-polar tip that passes the current through the patient to a grounding pad. In the case of mono-polar cauterization the tip of the instrument touching the tissue does the brunt of the work, while the weakened electrical charge passes through the patient to the grounding pad. (I hope that everyone is checking the insulation on their electrosurgical laparoscopic instruments after each use, since a break in the insulation can cause a “misfire” during a surgical procedure. Electrical current can pass through breaks in the insulation, and if this break is close to any other organ the current will take the closest route out of the instrument, damaging tissue that was not meant to be cauterized).  When these tips cauterize,  tissue, blood and body fluid are basically cooked onto the instrument. This burned on tissue or Eschar (your new $50.00 word) should be removed AT POINT OF USE. Many surgical “kits” come with a little scouring pad that the surgical tech should use to remove the eschar AT POINT OF USE. Each time the instrument is used the eschar should be removed, but we’ve all seen those bipolar forceps with layer upon layer of burned on blood and tissue come into decontamination.  I have capitalized and underlined “at point of use” twice now for a reason, The Association of Surgical Technicians, AORN, and AAMI all state in their recommended best practices that “The cleaning of instruments should begin during the surgical procedure to prevent drying of blood, soil and debris on the surface and within lumens.”(AST RSOP for the Decontamination of Surgical Instruments, Standard of Practice I). If you are constantly receiving electrical surgical instruments with layers of eschar on them, then someone in the OR is not doing their job correctly. Here I would suggest you get together with your manager arm yourself with photographs  of the instruments as evidence and written recommended best practices, the A.S.T. version is readily available on line and set up a meeting with the Director of the OR.

Now as far as the removal of eschar from electrosurgical instruments, my first recommendation would be the use of a stiff plastic brush, soak your instruments as recommended in their IFU preferably in a high quality multi-enzymatic detergent (see our deconex® Power Zyme Brush them under the soak water surface to remove the eschar. If staining from the burned on tissue is still a problem, and the material you are cleaning is stainless steel, I would suggest you use a surgical stain remover (deconex® 34GR is great for the removal of both organic and inorganic stains on surgical instruments and Washer/Disinfectors again refer to the IFU of the product you are using.

One more suggestion I would like to make is that if you are in a larger institution and have more than one washer, you dedicate one of your washers for instruments that are difficult to clean. Use a two component cleaning chemistry system in your washer (deconex® Twin pH10/Twin Zyme Two component cleaning chemistries like the “Twin system” employee both an enzymatic detergent and a mildly alkaline detergent  that when combined in the washer/disinfector  form an extremely effective cleaning system and have demonstrated efficacy in cleaning  hard to clean instruments like the DaVinci Endowrist instruments.


Our ASC is trying to figure out the correct standards for how often to change the water for cleaning instruments before reprocessing?

The water in the manual soak sink and ultrasonic cleaner should be changed when it becomes visibly soiled and at least once each shift. The soak sink and ultrasonic cleaner should be rinsed clean before refilling and at the end of the day or between shifts should be disinfected with a lint free cloth soaked in 70% alcohol.

If you are cleaning intraocular instruments, The American Society of Cataract and Refractive Surgery, The American Society of Ophthalmic Registered Nurses and AAMI ST79, Annex N all recommend that the water be discarded after EACH set cleaned. Also for intraocular instrument after cleaning and a tap water rinse all instruments should be rinsed in sterile, distilled or deionized water. This sterile water rinse should provide flow of water over and through the instruments, should not be done in a basin with agitation and should not be reused.

Always follow the cleaning chemistry manufacturers IFU for dosing/dilution ratios. Have your soak sink marked so that when you fill it to that mark you know the amount of water in the sink (e.g. 5 gallons) and dose your cleaning chemistry appropriately. The AAMI ST79 also recommends that you monitor and document the temperature of your soaking solution to make sure it stays in the correct temperature parameters suggested by the detergent manufacturer.

Our Surgical Center has been having a problem getting loaner instrument trays in a timely fashion. Sometimes we have to “cut corners” to get the trays processed for the surgical cases that needs them. What actions can we take to insure we get the trays in with enough time to process them properly?

Loaner instruments have been the bane of the Sterile Processing Department for what seems like an eternity. Every Sterile
Processing Technician , including myself, has a hundred or so horror stories of having to deal with them . I am going to skip my usual long crazy tirade here (yes I could really go nuts with this) and just start with my suggestions.

First, NEVER CUT CORNERS….NEVER!  Ethically you are obligated to “do the right thing” by complying with the manufacturers IFU for cleaning and sterilization. If loaner instruments arrive at 10:00am and are needed for an 11:30am case, you “cutting corners” to get them done only placates the surgeon and the sales rep. who brought them in at the time they did, the patient, who is your main concern does not benefit from this at all.  Ask yourself, would I want these instruments that have been improperly processed used on a member of my family or myself?  I’m sure the answer will be NO. I understand that this means you will have to “take a stand” and explain your actions to the everyone who is expecting these instruments to be ready (yes, I know they will be screaming about it too), so calmly explain that it is your ethical obligation to “do the right thing” (see above) and ask them if they would want improperly processed trays used on them or their loved ones.

Now if this seems to be a reoccurring problem, which it probably is, I suggest before the problem arises again, get together with the staff from the OR, get your Infection Control person involved, talk to the director of your ASC, even get other surgeons involved (they will listen if you explain the legal ramifications of a Surgical Site Infection from improperly processed instrumentation) and work on getting a policy together and in your facilities policy and procedure manual  to control this problem. Here I would suggest you use the IAHCSMM “Sample Policy and Procedure for Loaner Instrumentation”

as your template. This sample policy is wonderful and covers all the bases, from the responsibility of the OR staff, to the weight of instrument sets, to the responsibility of the sales reps pre and post surgery and of course the responsibility of the SPD/CSSD staff.   Once the policy is complete and documented in your facilities manual, make sure that all the sales reps. who bring you loaner instruments get a copy of it so they know of it and then hold them to it. Without a policy in writing and in your facilities policy and procedure manual, your plight will be a losing battle, so get one started ASAP.


Update…. Are there any approved values for residual protein on instruments after cleaning?

In September 2011 I received this question from a SPD Tech. in reference to an approved value for the amount of residual soil on surgical instruments by the FDA. My answer was that the US FDA had no approved value number. Although this may be true for hospitals and ASC’s, I was recently informed that there is an FDA approved value for residual proteinaceous soil on surgical instrumentation . This FDA standard is for third party Single Use Device reprocessors and it set at less than six point four micrograms of protein per square centimeter (<6.4µg protein/cm²).

Although I had heard this value before in reference to the cleaning of flexible endoscopes (Alfa et al. 2002) as the average soil marker for biopsy/suction channel of clean flexible endoscopes, I did not know that this value had been set as the FDA standard for SUD reprocessors.

This value is also the basis of cleaning verification tests for flexible endoscopes (eg. Healthmarks ChannelCheck™ ). Who knows, maybe one day this verification value will apply to all surgical instruments processed in Healthcare facilities and not just the SUD Reprocessors it applies to now?…only time can tell.

Our ASC has begun to do cataract surgery, we have not experienced any TASS infections yet and would like to keep things that way. What are your suggestions to our Sterile Processing Technicians when comes to the care of intraocular instruments?

There are multiple and varied substances that can cause the inflammation of Toxic Anterior Segment Syndrome, but in the case of intraocular surgical instruments the cause is most likely debris left from inadequate cleaning, residues from improperly dosed or rinsed cleaning chemistries, endotoxins from manual soak or ultrasonic cleaning chambers, lint from towels used to protect instruments or trays, and inorganic salts deposited from the steam in your sterilizer.

First I would like to suggest that you obtain a copy of the “Recommended Practices for Cleaning and Sterilizing of Intraocular Surgical Instruments” from the American Society of Cataract and Refractive Surgery and the American Society of Ophthalmic Registered Nurses and familiarize yourself with it.

That being said let me begin with saying that the care of these (and any other surgical instrument for that matter) begins at the point of use, keeping instruments free of debris and moist, with sterile, distilled or de-ionized, water during the procedure will help insure your technicians will be able to clean and sterilize them properly when the procedure is finished. Also the sooner the instruments are decontaminated, once the procedure is finished, the easier they will be to clean. Since Ophthalmic Viscosurgical Device Solutions can harden in minutes, I would suggest the use of disposable cannulas and tubing whenever possible. Any non-disposable cannulas (or instruments) that come in contact with these solutions should be flushed and keep moist with copious amounts of sterile water to prevent deposits.

Once the instruments arrive in decontamination cleaning should begin immediately. Always follow the instrument manufacturers IFU when it comes to cleaning these instruments. If enzymatic detergents are contraindicated for cleaning, do not use them, if they can be used, I would suggest using a neutral pH enzymatic detergent that is both color and fragrance free (please see my answer to the question “We prefer an enzymatic detergent with coloring and fragrance…” for further discussion on this matter). Always follow the detergent manufacturers IFU, when it comes to the dosing of their detergent in solution for cleaning. If you have an ultrasonic cleaner, only use it with those instruments that can be cleaned in it.

When it comes to the cleaning of ophthalmic instruments, it is highly recommended, weather in the manual soak sink or ultrasonic cleaner, that you change the cleaning solution between each tray, to avoid the deposit of debris from previous trays on instruments. Also more frequent cleaning and disinfection of the chamber of your ultrasonic cleaner and soak sink is highly recommended to prevent the build-up of bacterial endotoxins which can deposit on instruments.

Once the instruments have been cleaned with detergent, rinse them with copious amounts of water to remove any detergent residue, tap water may be used here unless contraindicated by either the equipment or detergent manufacturer. This should be followed by a final rinse with sterile, distilled or de-ionized, water. This rinse should provide flow over and through the instruments. The final rinse water should not be reused and agitation of instruments in a basin of sterile water should not be used since any debris
could redeposit this way.

Following the final rinse all lumened instruments should be dried with medical grade compressed air. When assembling instrument sets, closely inspect all instruments for defects or debris, a lighted magnifying glass is highly recommended here. If you normally use huck-towels to line your instrument sets, please make sure that they are both lint and detergent residue free. Call your linen provider to find out what chemistry is used to wash these towels because a highly alkaline detergent may transfer chemicals from the towels to the instruments during sterilization, I have even seen the dye from new huck-towels transfer to trays so find out from your linen supplier if they have ever had any incidence with this problem.  A better choice for tray liners are the specially made disposable dye and residue free paper liners you can get from many sterilization supply companies.

Since dissolved inorganic salts in the steam of your autoclave can deposit on your instruments and my trigger inflammation, have the quality of your steam checked, at least on a yearly basis.




We use a TOSI test on a plastic strip in our washer for washer verification; however, you recommend the TOSI test with a metal coupon. Is there a difference between these two tests?

Yes, there is a BIG DIFFERENCE between the two tests!

What you are using is actually called a Browne STF load-check: this test consists of polysaccharides (sugars), protein and lipids, derived from eggs and porcine (pork), that are printed on a plastic strip. This plastic strip is placed in an L shaped perforated metal holder prior to washer testing.

The TOSI test (Test Object Surgical Instrument) is composed of purified bovine (beef) proteins, haemoglobin, and blood fibrin layered on a stainless steel plate. Furthermore, the metal plate has been scratched to replicate the surface of surgical instruments and covered with a see-thru plastic holder that replicates a box-lock. The plastic holder itself is capable of clipping into a wire sterilization/washer basket prior to washer testing. The producers of this test also make a similar test for washers with lumen cleaning capability.

There are also other tests on the market to verify your cleaning processes. Wash-Check, for instance, consists of proteins mixed with a solvent polymer metered on a metal plate. It has a special holder for placement in the washer that replicates a box-lock. This company also produces a similar lumen cleaning test.

When I mentioned washer verification tests in the past, I reiterated AAMI’s recommendations that washer–disinfector verification tests be performed on a metal coupon since this most closely replicates the surface of surgical instrumentation. Of these tests, AAMI also considers tests composed of “blood test soil” to be the most “valuable as a quality assurance indicator for functionality of a washer-disinfector.”

The ASTM (American Society for Testing and Materials International) also states in their Blood Cleaning Efficiency of Detergents and Washer Disinfectors (ASTM D7225-06), “the regular use of blood soil test is a systemic challenge to the functioning of an automated washer” and recommends these tests be performed on “stainless steel plates.” The ASTM also gives recommendations on what this soil should be composed of. The ATS (artificial test soil) used on TOSI tests is extremely safe: yes it is composed of bovine blood, but this a highly purified product so there is no fear of “catching anything.”

During my years of working in Sterile Processing, it has been my experience that most of the soils I cleaned off instruments in “decontam” were blood based. Rarely, if ever, did I see sugar and eggs on a Finochetto retractor! Moreover, the majority of the instruments placed in the washer-disinfector were made of stainless steel. Since blood is the major source of soil on surgical instruments (and most often it is coagulated and dried on stainless steel), it poses the greatest challenge in cleaning. I believe it only makes sense that we challenge the cleaning efficacy of our washers with the same soil substances and under the same conditions.

The other thing to remember is this: these tests are not made for specific washers; rather, they are made for testing ALL washers and made to challenge the efficacy of YOUR wash cycle. If a test doesn’t pass, it is not because it is too difficult for your washer to clean. Instead, it means the washer needs to be checked! There could be multiple reasons why. For example, a spray arm could be blocked and not turning, or the wash cycle water temperature is too high or low. Perhaps the machine is not dosing the correct amount of detergent to get the job done, etc. The list goes on and on.

What we all need to remember is this: the primary reason for testing washer-disinfectors is the fact that it is a replicable cleaning process that needs to perform correctly every time it is used.

So ask yourself: why wouldn’t you want a test that replicates the worst case scenario in your washer?