腹腔镜仪器和设备的消毒和保养

Sterilization and Upkeep of Laparoscopic Instruments & Equipment

                               
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INTRODUCTION:

Laparoscopic surgery requires sophisticated and precisely calibrated instruments. The essential difference between instruments used in open surgery and people utilized for laparoscopic surgery would be that the latter are more complex in design and yet delicate in construction. Thus the laparoscopic instruments are more vulnerable to lodging of bioburden (micro-organisms and debris) within their crevices. Thus, the LI are difficult to clean, sterilize adequately and maintain as compared to their counterparts used in open surgery. Moreover, owing to their delicate design, gentlest methods have to be used for cleaning in addition to sterilization. Also, meticulous cleaning, maintenance in addition to sterilization are necessary so that not to compromise the safety from the patient, the surgeon or other operating room personnel. The rise in complexity of the laparoscopic procedures as also the emergence of resistant strains of bacteria, mycobacteria, fungi and viruses makes it imperative to effectively clean and disinfect instruments. Sterilization is the absolute elimination or destruction of forms of microbial life. It may be achieved with steam, gas or chemicals. However, disinfection is the relative removal of pathogenic organisms except spores.

Disinfection can be:

a) High level - where all life forms except the spores are destroyed,
b) Intermediate level - where some fungi, viruses and spores are spared, or
c) Low-level - where fungi, viruses, spores and mycobacteria remain undestroyed. For laparoscopic instruments ideally sterilization or at best higher level disinfection should be used.

CLEANING AND STERILIZATION

Optimal processing of LI involves several steps that reduce the risk of transmitting infection from used instruments along with other what to healthcare personnel.

They are

1) Dismantling,
2) Decontamination,
3) Precleaning,
4) Cleaning and rinsing,
5) Drying
6) Sterilization and
7) Storage. For proper processing, it is essential to perform the steps in correct order.

Most major hospitals have a Central Sterile Supplies Department where the instruments are transported in the operating room for processing. Even in hospitals or nursing homes that do not have an elaborate CSSD, the fundamental steps in processing of instruments can be followed provided a well-established protocol is in place, and designated personnel receive the responsibility for the same. Proper processing of instruments forms an intrinsic aspect of their care which should undoubtedly significantly help in increasing their life time and trouble-free service.

Dismantling

The look of LI should be so that they ought to allow easy dismantling. Instruments that can't be dismantled completely are prone to harbour blood / debris within the shafts and compromise safety of the patients in whom they are utilised subsequently

Decontamination

Decontamination is the procedure used to reduce bioburden on reusable medical devices. The procedure begins in the theatre itself using the nursing staff wiping off visible blood tissue and body fluids in the instruments with a damp sterile sponge. At the conclusion of this all soiled or contaminated instruments should be placed in a container containing a disinfectant solution such as 0.5% chlorine and allowing them to soak for Ten minutes.

The instruments shouldn't be left on this solution for longer period of time as they could get damaged. Once the instruments get to the CSSD, a purpose-built bath is used for decontamination of their decontamination just before proceeding using the next step in the cycle. Modifications of the standard cleaning processes have to clean rigid endoscopic instruments effectively. Instruments designed with an external gasket, an internal seal that does not totally occlude the internal space, or no gasket ought to be placed in the vertical position in enzymatic cleaning and rinsing solutions, instead of the standard horizontal position, so the air trapped within the instrument is permitted to escape and replaces using the solution. All solutions should be irrigated through cleaning ports of instruments. During the process of manual cleaning, special attention ought to be given to intricate and delicate operating mechanisms located at the distal end of many instruments. An ultrasonic cleaner will boost the cleaning of hard-to-reach places. At the end of decontamination, the instrument should be safe for handling without contact with blood-borne pathogens.

Precleaning

Following the instruments reach the sterile supplies processing area, which is preferably a controlled environment, a pre-cleaning treatment with an enzymatic method is recommended. Numerous enzymatic products are available, viz. protease, lipase, amylase, which are effective in enhancing the cleansing process for difficult-to-clean instruments. These break up blood and other protein soil and facilitate cleaning. These enzymes are proteins, and must be removed by thorough cleaning.

Cleaning

Any instrument designed for autoclaving requires specialised cleaning just before sterilization. Users need to ensure that no residual, proteinaceous material or organic residue remains about the instrument surface. This is particularly important where the instrument has several small moving parts and crevices; build up of residues may eventually result in corrosive damage and pathogenic colonization (bioburden). Many hospitals adopt the technique of washing their instruments in soap scrubs. Although physical cleaning is partially effective, enzymatic and detergent based cleaners which dissolve and lift organic material from the surface of instruments are better suited to making certain instrument surfaces do understand of blood along with other body fluids and proteinaceous material before the sterilization process. For laparoscopic instruments this really is best completed using soft brushes that allow the inner surfaces from the instruments to be cleaned thoroughly.

Laparoscopic instruments are best rinsed in running water to ensure that all of the particulate matter in addition to residues of chemicals employed for contamination and cleaning are completely cleared from them. It is useful to possess “cleaning guns” with fine, pointed nozzles to wash theshafts from the laparoscopic hand instruments. The jet of water has the capacity to clean these instruments much better than rinsing them in stagnant water.

A method of cleaning that's growing in popularity is ultrasonic cleaning. This method is, by far, the most efficient and effective available today. Its simplicity of use and superior efficiency is quickly making ultrasonic cleaning the preferred choice. Actually, ultrasonic cleaning is 16 times better than hand-cleaning. The instruments are placed in the ultrasonic unit for 10-15 minutes and use a neutral pH solution. Attention should be directed at the next points during ultrasonic cleaning:

• Before placing into the ultrasonic unit, the instruments are cleaned of all visible debris.
• It’s preferable to not mix instruments made of dissimilar metals (such as aluminum and stainless) in the same cycle.
• It is important to ensure that the instruments have ample room. The ultrasonic cleaner shouldn't be overloaded.
• As with all types of cleaning, all instruments ought to be opened so ratchets and box locks are fully subjected to the cleaning process.
• Upon completion of the cycle, the instruments are removed immediately and rinsed.

Drying

The instruments should be dried at the end of the cleaning and rinsing cycle before they are packed for sterilization. This really is ideally achieved by using an air gun that blows all the water droplets off the surfaces of instruments or by using an oven. The second, however, may be available only in CSSD units.

Sterilization

The Centers for Disease Control (CDC) recommends that rigid laparoscopic instruments be sterile or, in the event that isn't feasible, they be high-level disinfected. There are three sterilization processes available to us - steam, ethylene oxide and peracetic acid. Because of product knowledge and proprietary design information, the instrument manufacturer may be the just one who can provide sterilization recommendations.

Steam sterilization

Steam sterilization in an autoclave is among the most typical forms of sterilization used in healthcare facilities. Autoclaving at 121 0C for 15minutes is ideal for all reusable metal instruments. It's effective, cheap and non-toxic. Laparoscopes may be sterilized by flash or vacuum steam sterilization. Before sterilization, all instruments that are insulated, all silicone tubing, and all sorts of cords ought to be doubly covered with a cloth to prevent connection with the hot metallic container. They are then put into the autoclave. Flash sterilization is carried out at 135 0C at 30 psi pressure for 60 minutes. This process requires post-vacuum and dry cycles. The instruments should rest on the sterilizer rack for 45 minutes to prevent water condensation about the lens all cords should be doubly wrapped in a cloth to avoid contact with the hot metallic container. They're then put into the autoclave. Flash sterilization is completed at 135 0C at 30 psi pressure for An hour. This method requires post-vacuum and dry cycles. The instruments should rest on a sterilizer rack for 45 minutes to prevent water condensation about the lens.

Gas sterilization

Using ethylene oxide (EO) would work for all disposable instruments, insulated hand instruments and tubings employed for gas, suction and irrigation. Endoscopic instruments may be sterilized with either cold or warm EO gas, with respect to the manufacturer’s instructions. With cold gas, the temperatures are set at 85 0C and also the instruments are subjected for 4 hours and 30 minutes. Aeration must then follow for 12 hours. Warm gas sterilization happens at 145 0C for 2 hour 30 minutes, followed by 8 hours aeration. The benefits of EO are how the items aren't damaged, it's non-corrosive to optics also it permeates porous material. Its main disadvantages are its cost, toxicity, the requirement for aeration and being a longer process.

High level disinfection

When sterilization isn't available or feasible, high-level disinfection (HLD) is used for instrument processing. HLD eliminates bacteria, viruses, fungi, and parasites but doesn't reliably kill all bacterial endospores, which cause diseases such as tetanus, gas gangrene and atypical mycobacterial infections. HLD would work for items which will come in connection with broken skin or intact mucous membranes. The effectiveness of HLD depends on (a) the amount and kind of microorganisms, organic material (blood, other fluids, tissues), and other matter (for example dirt) present on the instrument or other item and (b) the quantity of protection them provides the microorganisms (such as if the item has grooves or the areas by which microorganisms can hide). Therefore it is important to decontaminate and thoroughly clean instruments along with other items before HLD.

Agents that are employed for HLD include 2% glutaraldehyde, 6% stabilized hydrogen peroxide and per acetic acid (acetic acid/hydrogen peroxide).
Glutaraldehyde has got the benefits of having good biocidal activity, non-corrosive to optics and it is active in the presence of protein. Glutaraldehyde is irritating towards the skin, eyes, and respiratory system, especially at concentrations of 0.3 parts per million (ppm). The length of time that commercially available glutaraldehyde solutions may be used varies, usually from 14-30 days. It ought to be tested daily with the manufacturer’s test strip. Always stick to the manufacturer’s instructions regarding proper storage temperatures and expiration date. Solutions should be replaced any time they become cloudy. The efficiency of glutaraldehyde is influenced by the organic load, contact time and use pattern, concentration, physical configuration of instruments, temperature and pH. OSHA’s established maximum allowable exposure limit for glutaraldehyde is 0.2ppm. Fibreoptic light cords and telescopes have to be soaked in 2% glutaraldehyde not less than Ten minutes. Soaking should not exceed Twenty minutes. The endocamera could also disinfected by 10 minutes submersion in 2% glutaraldehyde. Care must be come to leave the plug end of the cord away from solution. Alternately, sterile drape over the camera and cord may be used. Soakage of other metallic instruments, including trocars, and hand instruments, has become recommended for An hour, to avoid infection with atypical mycobacterial infection. Formaldehyde, glutaraldehyde from phenolic derivatives, iodophors, hypochlorites, phenolics and quartery ammonium compounds are unpopular and it has been condemned. Formaldehyde is potentially cancercausing and very irritating to the skin, eyes, nose, and respiratory tract. Furthermore, its efficacy is found wanting, and for that reason, routine utilization of formaldehyde for sterilizing instruments and other items isn't recommended.

Newer methods of sterilization

Important for hospitals with high workload is the rapid turnaround times for instruments that can't be sterilized satisfactorily with steam or dry heat. One of the newer sterilizer system - STERRAD (Johnson & Johnson) - uses hydrogen peroxide vapor and low-temperature gas plasma to sterilize most devices quickly with no toxic residues. Usually, the process takes about 75 minutes for wrapped and dry instruments and devices. Within the chamber, a deep vacuum is drawn. Fifty-nine percent aqueous peroxide is vaporized into the chamber. The product will be enveloped within the peroxide vapor. Following a diffusion of the gaseous peroxide with the load, chamber pressure is reduced, permitting the generation of low-temperature gas plasma. Rf (RF) energy is put on the chamber via an RF amplifier, inducing the plasma state. Reactive species are generated in the peroxide on this state, reacting with materials and every other. When the high-energy species have reacted, they recombine to form water vapor, oxygen, along with other non-toxic byproducts. Upon completion of sterilization, instruments are dry for immediate use or sterile storage. Thus, recontamination risk is minimized, and given that they remain sterile until their next use, money and time is saved by avoiding reprocessing instruments when the case in canceled or delayed. This system occupies minimal space and requires no venting or water hookup. The only utility requirement is electrical hookup.

Storage

Items ought to be used or properly stored soon after sterilization or HLD so they do not become contaminated. Proper storage is as important as proper decontamination, cleaning, sterilization, or HLD. If items aren't stored properly, all of the effort and supplies used to properly process them will have been wasted, and the things is going to be contaminated. Specific instructions for proper storage rely on whether sterilization or HLD continues to be performed, the method used, and whether the items are wrapped or unwrapped.

The shelf-life of a wrapped item is suffering from numerous factors, including:
• The kind of packing material used
• The number of times those is handled
• The number of people who handle the pack
• The cleanliness, humidity, and temperature from the storage space
• Whether the packs are stored on open or closed shelves
• Whether dust covers (for example sealed plastic bags) are utilized

For optimal storage, sterile packs are put in closed cabinets in areas that aren't heavily trafficked, have moderate temperatures, and are dry or of low humidity. Under optimal storage conditions and with minimal handling, properly wrapped items can be considered sterile as long as they remain intact and dry. Storage time and the handling of sterile packs ought to be kept to a minimum, because the probability of contamination increases over time and with increased handling. When in doubt about the sterility of a pack, consider it to become contaminated and resterilize the item before use.