The optimal surgical instrument cleaning protocol will break down all forms of proteinaceous bioburden and clean the surface, thereby enhancing the passive layer of surgical instrument stainless steel. Surgical instrument manufacturers place the chromium 'passive layer' on the surface of surgical instruments to reduce the corrosion and pitting of surgical instruments. Cleaning the surface of surgical instruments properly improves the strength of the passive layer and thereby the performance and usable life of surgical instruments.
Inadequate cleaning can result in material remaining on the surgical instrument which will prevent disinfection and sterilization fluids or gases reaching all parts of the potentially contaminated device. Inadequate sterilization or disinfection sterilization and may in turn result in transmission of infectious organisms when the device is reused. The intricate design and delicate materials of flexible scopes complicate the cleaning process. This requires repetitive and consistent oversight.
The reprocessing decontamination Cleaning of Surgical Instruments, whether done manually or automatically in a surgical instrument washer decontaminator disinfector, can only be effective if "cleaning" is adequate. Effectively sterilizing surgical instruments (Generic Sterilization with a Pre-Vacuum Sterilizer (HI-VAC): 270-272° F (132-134° C), 16-minute exposure time, with 4 pulses and a 30-minute dry time. Generic Sterilization with a Gravity Displacement Sterilizer: 270-272° F (132-134° C), 30-minute exposure time, with a 30-minute dry time.) is not possible if "cleaning", the "prerequisite for sterilizing surgical instruments", is not adequate. All disinfection processes, whether done manually or done automatically in a surgical instrument washer decontaminator disinfector, can only be effective if prior cleaning is adequate. Effective disinfection or sterilization of an inadequately cleaned surgical instrument or scope is not possible. Endoscopes should be cleaned with an enzymatic enzyme detergent compatible with the endoscope immediately after use and before manual or automated disinfection. Cleaning involves the entire endoscope, including valves, working channels, connectors and all detachable parts. High level enzymatic enzyme detergent formulations ("Enzymatic" Surgical Instrument Cleaners), in combination with a high level surfactant chemical complex, have been shown to be effective in removing stains, hard water deposits, and encrusted bioburden, while being safe to use for rigid or flexible scopes.
Enzyme Cleaning Concentrates
Enzyme cleaning concentrates function more effectively at temperatures above room temperature. The optimal range begins as > 22C - 72°F with performance reaching it's peak at 58.3C - 137F. This is often referred to as the optimal temperature for the performance or activity of enzymatic action. The activity of enzymes does not stop at higher temperatures but the level of performance does begin to decrease. Enzyme cleaning concentrates enzyme-detergents and all-in-one cleaning concentrates, which include enzymes, should be used in accordance with the manufacturer's recommendations and the recommendations of the medical devices being cleaned.
The approach for cleaning surgical instruments can be the same if the presence of pathological prions (including the prions of vCJD Creutzfeld-Jakob disease) however the attention to detail is more important. It is known, that prions are unusually resistant to disinfection and sterilization by the physical and chemical methods used for decontamination of infectious pathogens. It is a difficult task to gain a consensus opinion on what constitutes optimal and practical conditions for decontamination of prions. Numerous studies have been conducted, but they do not reflect the reprocessing procedures for surgical instruments in a clinical setting. The clinical setting is critical for iatrogenic transmission, the passing of a disease from an infected individual or group to a previously uninfected individual or group. The method of reprocessing prion contaminated surgical instruments includes (1) decontamination by NaOH or NaOCl for 30 or 60 minutes followed by GL-autoclaving at 121°C for 30 minutes, (2) cleaning and (3) routine PL-sterilizing at 134°C. It is known that some surgical instruments cannot be decontaminated by heat and moisture. Disinfectants have been widely used for this purpose even although the disinfectants are ineffective. The most common practice believes that the only completely safe way to prevent transmission of vCJD is to use single-use surgical instruments. Because of the pervasive distribution of these infectious proteins and the long incubation time of the disease, reprocessing cleaning surgical instruments has been identified as a high risk factor for nosocomial transmission of vCJD. Research has shown that the agent of the vCJD disease, an infectious prion protein, is extremely resistant to today’s sterilization methods; therefore, the argument, “It does not matter if instruments are 100 percent clean, as they will be sterilized,” is definitely no longer valid. Today, we understand that cleaning surgical instruments is as important as the sterilizing the surgical instruments. Today’s surgical instrument cleaning process requires increasingly sophisticated surgical instrument cleaning concentrates. Detergents, which are used in these processes, can be mild, with a neutral pH, or they may be more aggressive, with values in the alkaline range of the pH scale. A number of hospitals and surgical centers are effectively using neutral pH “combination” enzymatic enzyme detergent cleaners for reprocessing surgical instruments. The “combination” enzyme detergent cleaners provide optimal cleaning as well as the highest possible level of care for surgical instruments and scopes. The manufacturers of surgical instruments strongly recommend the use of Neutral pH cleaners to enhance the "passive layer" of instrument protection. The early prion inactivation approach, using a high concentrate of sodium hydroxide solution or sodium hypochlorite combined with long holding times, is generally lethal for medical surgical instruments and washer-decontaminators- disinfectors. Recently, researchers have been looking is a minimally destructive method to decontaminate surgical instruments potentially contaminated with prions. The use of “combination” enzyme detergent surgical instrument cleaners has offered the highest level of cleaning outcomes.
Surgical Instrument Cleaner cleaning surgical instruments cleaner.
Ultrasonic cleaning of reusable endoscope accessories and components may be needed to remove material from hard-to-clean areas. The same detergent used for ultrasonic cleaning can be the same as used for manual cleaning. Recommendations for detergents used for ultrasonic cleaning are as follows:
• a non-foaming detergent must used
• the labeling of the detergent should recommend the use of the product for ultrasonic cleaning
• always use enzymatic detergents for instruments soiled with bioburden (protein, fats, starch)
• use detergents with 'surfactant' cleaning agents for removing stains and hard water mineral deposits
• the treatment cleaning time recommended by the medical device and detergent manufacturers should be observed
• avoid the inhalation of enzyme-containing detergent aerosols (risk of anaphylactic reactions) by maintaining a cover over the ultrasonic cleaner when in use.
Ultrasonic cleaners are very effective when used with hot water per manufacturer’s recommended temperature and specially formulated detergents. It is recommended that all visible debris and blood be removed from the instrument prior to ultrasonic cleaning. Sort instruments by similar metals to prevent corrosion due to the contact of dissimilar metals. (electrolytic deposition - galvanic corrosion) It is not recommended to clean plated instruments in an ultrasonic cleaner since the ultrasonic vibration and the presence of other sharp instruments may crack or rupture the plating. Because Ultrasonic Cleaners do not provide the complete "proper sequence of treatments" i.e. final rinse(s) that are purified, purged between treatments, and/or have temperatures elevated to disinfection levels, they are not considered to be as clinically effective as automated washer-decontaminators- disinfectors. Ultrasonic Cleaning can effectively remove: long term encrustation and surgical cements or glues that have dried onto instrumentation. Always refer to the printed manufacturer recommendations prior to using Ultrasonics.
Recommendations for Maximizing the Efficacy of Ultrasonic Cleaning
• items being cleaned must be fully immersed
• hinged instruments must remain open during treatment
• only use cleaning trays that do not obstruct the ultrasonic cleaning process or add mass (e.g. wire baskets)
• large surface bulky items such as kidney shaped bowls must be positioned not to create anechoic (shadow) zones that will block the efficacy of ultrasonic transducer waveform. Position such items vertically or put them on top of the other items.
• always sort instruments by similar metals to prevent corrosion
• do not overload the ultrasonic cleaning tank with excessive mass as this will reduce the efficacy of cleaning
• the soil being removed from devices being cleaned adds to the mass within the tank and decreases the efficacy of the ultrasonic cleaner. Review the level of soil and renew the ultrasonic bath as needed
• ALWAYS follow ultrasonic cleaning with separate rinse treatments. Ultrasonic cleaning will fragment and loosen soil but will not necessarily remove the soil from the surface of the surgery instrument being cleaned.
For the cleaning of endoscopes, detergents with or without enzymes, and detergents containing antimicrobial substances may be used. Use of non-foaming detergents is recommended. Foaming can inhibit good fluid contact with device surfaces, and prevent a clear field of vision during the cleaning process with a risk of injury to personnel.
The detergent selected should effectively loosen organic and non-organic material so that the flushing action of the detergent fluid and subsequent rinsing water removes the unwanted material. Combination all-in-one Enzymatic Surgical Instrument Cleaner detergent complexes have been shown to be highly effective.
Aldehydes Contained in Cleaning Concentrates for
When using Cleaning Concentrates which contain Aldehydes, be aware that they denature and coagulate protein.
Amine Compounds or Glucoprotamine in combination with Glutaraldehyde and Cleaning Concentrates
Detergents based on amine compounds or glucoprotamine in combination with glutaraldehyde for disinfection should not be used as chemical reactions may result in formation of colored residues. These residues can appear to be corrosion. The use of a high level cleaning surfactant "combination" enzyme detergent instrument cleaner can be used to remove the corrosion-stains, and prevent corrosion or stains.
John Temple, Product Development