Cleaning Catalog

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Sontec Instruments A guide to ensure you, that every time you need an instrument to work properly, it Does.

Everything you ever wanted to know about surgical instruments AND A LITTLE BIT MORE...

7248 South Tucson WayEnglewood, CO 80112(303)790-9411(800)821-7496Fax(303)792-2606

2 In 1937 the author first realized the importance of checking surgical instruments in the operating room. In those days most of the surgeons owned their own instruments. Problems were many for the Operating Room supervisors because the number of surgical instruments surgeons had was limited. Surgeons were forced to borrow from each other to complete their sets, especially when some of their instruments were set aside for repair. In an average hospital it was not uncommon to have 20 to 25 surgeons each owning his personal instruments. It was necessary for Operating Room supervisors to receive the surgeons permission prior to having his instrument repaired. If a surgeon worked in several hospitals in a city, his instruments had to be transported from one hospital to another. In emergencies, the OR supervisor had to improvise to make up sets, and much dissension occurred among doctors as to who had borrowed their instruments. George Pencer taught many nurses the technique of checking instruments, and in hospitals of 200 beds or more , he would actually set up portable repair equipment allowing the repair and sharpening of instruments without removing them from the hospitals. Since 1937 many advance in the quality, repair, and ownership of surgical instruments have taken place. But we feel this handy check list, reviewing the care and maintenance of surgical instruments, should still prove helpful for all members of the surgical team. Forceps and Hemostats A surgeon faces a most irritating and frequently frustrating problem when a forcep or hemostat does not function properly. In most cases, this can be avoided if a surgical nurse knows how to check and test these instruments correctly before including them in the surgical sets. Forceps are probably abused more than any other instrument. Experience indicates that breakdown of high quality forceps is often the direct result of their misuse. They are most frequently misused in orthopedic surgery. Here they are often applied to steinman pins, bone plates, screws, and nails-usually when pliers are not available. They also are used to clamp large sponges, tubing, needles, etc. The smaller the misused forcep, for example a Mosquito or Kelly, the greater the damage. As the jaws of a forcep are overloaded, inevitably misalignment of the jaws occurs and reduction of tension in the shanks. Thus, the instruments effectiveness is greatly impaired. When this situation occurs in a Kelly or similar type instrument, the forcep will not hold tissue securely: therefore, failing to accomplish the job for which it was intended. If a surgeon continues to use the instrument, further damage at an accelerated rate will result. For example: when the jaws of a Allis clamp do not align, the teeth will not mesh properly, and they will break or wear very rapidly. When the jaws of an Ochsner forcep do not align and a surgeon

continues to use it, the tooth on the male jaw usually breaks off. Thus, not only is the instrument destroyed, but pieces of the tooth may be lost in surgery. How to test a forcep for jaw alignment Start with a visual test. Close the jaws of the forcep lightly. If the jaws overlap, they are out of alignment . On forceps with serrated jaws, observe to see if the teeth are meshing properly. Holding the shanks of the forcep in each hand , with the forcep open, try to wiggle the instrument. If the box lock has considerable play, and if it very loose, this will cause jaw misalignment. If this occurs, the instrument is faulty and should be repaired. Forceps and Hemostats which spring open It is extremely annoying to a surgeon, and hazardous to the patient, when a forcep or hemostat springs open; especially when clamped on a duct or a large vessel, such as a kidney pedicle. Operating room nurses have surely seen this happen. The above problem is usually caused by forcep misalignment, worn ratchet teeth, or by lack of tension at the shanks. As ratchet teeth are subject to constant metal to metal wear, they are the fastest wearing parts of a forcep. By constant strain of closing and opening the instruments, there is continues friction and wear; in particular on the first ratchet tooth. Therefore, when a surgeon takes a large bite with the forcep and locks it on the first ratchet tooth, a small jar of any kind may cause it to spring open. How to check the ratchet teeth on instruments Clamp the forcep on the first tooth only. When clamped, the instrument should produce a sounding snap. After the instrument is locked on the first ratchet tooth, take and hold the instrument at the box lock; then tap the ratchet teeth portions of the instrument lightly against a solid object (a weighted vaginal retractor is ideal). If the instrument springs open, it is faulty and should be repaired. How to check the tension between the shanks Close the forceps lightly. When the jaws touch, there should be a clearance of 1/16" or 1/8" between the ratchet teeth of each shank. Such clearance provides adequate tension at the jaws when closed. For a forcep to work effectively and efficiently, the jaws must align and meet exactly; the serrations should mesh correctly; the shanks should be flexible and resilient to compensate for a larger bite. The ratchets must hold. The forceps, when closed, must not spring open. The ratchet teeth should slide over each other smoothly when opening and closing. In short, the forceps should open and

close easily, permitting the surgeons to work rapidly and efficiently. Orthopedic Instruments Chisels, osteotomes, and gouges in constant use need sharpening and honing at frequent intervals. If they are accidentally misused, such as on a steinman pin, bone plate, or screw, the edges become dull and nicked. In these cases, the instrument should be sharpened immediately. Your author has been told that it is difficult for a surgeon not to occasionally encounter a pin, a bone plate, or a screw with an osteotome; particularly when it is necessary to remove an old plate which has some bone growth around it. In such a situation , it is prudent to have an older or special osteotome or chisel available for the surgeon. In the regular course of cleaning and sterilization, care must be exercised not to hit the edges of the chisels, gouges, and osteotomes against each other or other instruments. Such jostling not only dulls the edges of the instruments, but it can also chip or dent the sharp edges. Visual test for checking orthopedic instruments Check for nicks and burrs on edges on chisels and osteotomes. On bone cutting forceps and double action ronguers, one should again check to see whether the jaws align. If the screws at the fulcrum are slightly loose, the jaws inevitably become misaligned; consequently damage occurs to the jaws when the instruments are used. Frequently, a bone cutting forcep or ronguer is used to cut wire or a pin. To preclude this practice, it is very important to have wire cutter or pin cutter available to the surgeon. Orthopedic instruments are very expensive; therefore, they merit exceptional care. Tonsil Instruments Adenotomes The proper fitting of the adenotome blades is a problem. An adenotome blade should slide smoothly in the channels of an adenotome. When closed the blades should not overlap the adenotome. If overlapping does occur, the blade is too long and could be hazardous in use. If the blade is to short , it will not close completely, causing tearing of tissue rather than a clean cut. Check the blades. Be sure they slide smoothly and close so that no visible light can be seen between the tip of the blade and the adenotome. When ordering new blades, send your adenotomes to your surgical instrument repair company and have the blades fitted to each adenotome. This is very important because no two adenotomes are alike, even though they may be the same size. Also, be sure to have each blade stamped or lettered with the same code number as the adenotome. For instance, if the adenotome is coded 1-A, the blade should be coded 1-A. This identification procedure insures a proper fitting blade

3 for each adenotome. Tonsiltomes If blades do not close properly, the sluder presents the same problem as ill-fitted adenotomes. In checking, be sure the blade slides close, so that no light is visible between blade and tip of tonsiltome. Also, the blade should not extend beyond the tip of the tonsiltome. Tonsil Snares On tonsil snares, Tydings and Eves type, one should inspect the tip of the cannulas. Tonsil snare wires have a tendency to wear grooves into the tips of the cannulas, thus causing the wire to stick or catch and not pull through the cannula completely. If the wire sticks, it will have a pulling and tearing effect on the tissue instead of a clipping effect. If grooves are visible in the tips of the cannulas, the instrument should be repaired. Eye Instruments Cataract Knives, Keratomes It is very important to know how to test a cataract knife correctly. Once the eye surgeon penetrates the conjunctiva of the eye with a cataract knife only to discover it will not cut, he is in trouble. A small buckskin is the proper device for detecting a faulty knife. This item is a must for testing eye knives. To make the test, lay the handle portion of the eye knife across the palm of your hand. Do not touch it with your fingers. Hold the buckskin drum in your other hand. Then, push or slide the knife blade through the buckskin drum while it still rests in you palm. The blade should penetrate the drum as though it were passing through butter. If it sticks or has a tearing effect, then the knife is in need of repair. The same procedure is used for testing Keratomes. Extreme care should be taken in handling all eye instruments. Too much emphasis cannot be given to this matter. During cleaning and sterilization, caution must be taken to prevent the instruments from touching each other. Metal to metal contact should never be permitted. Eye instruments, even at best, can stand improvement. There are a number of other fine eye cutting instruments which are too numerous to mention in this article; however, the same procedure of care should be followed on them as on the cataract knives previously discussed. Scissors Scissors, especially Mayo operating and Metzenbaum dissecting, which do not cut on the tip of the blades can cause surgical havoc. Not only should a dissecting, or an operating scissor, cut tissue on the tips, but it is also

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important that the scissor blades glide over each other smoothly. Only a correctly ground scissor with properly set blades can provide this action. The precise setting of the blades is very important. To achieve this state involves a highly skilled procedure. And it takes an exceptionally skilled craftsman with years of experience to grind and set blades correctly. Various types of scissors are made for different types of use. It is important, therefore, that the surgeon has the proper scissors available to him. Light, fragile scissors, such as eye scissors with fine blades, should be meticulously guarded against misuse. For the surgeon to work quickly and methodically, an eye scissor must have a particularly smooth and delicate action and cut on the tips of the blades. Dissecting scissors are made for the accurate cutting and dissection of tissue. The tips and edges of the blades of these scissors should not be used for any other purpose. If a dissecting scissor, especially a Metzenbaum, is used for cutting heavy sutures or catgut, not only will the edge be dulled, but there will be a tendency for the blades to separate thus causing the scissors to loosen and lose their effectiveness. Suture scissors should be available to the surgeon for cutting sutures. Wire of any kind should never be cut with scissors. A wire cutter should be available for this purpose. A scissors should be used only for its intended purpose. Sharpening surgical scissors is a highly skilled procedure. Very often when scissors are incorrectly ground by a incompetent repairman, the blades become overheated. Consequently, they loose their temper, and the edge of the scissors is caused to soften. This situation practically ruins a scissor because the blades will not hold their edges and must be repeatedly sharpened. Constant sharpening, in turn, causes the tips to eventually become pointed and sharp . In addition , the fact that they do not close properly makes the instrument useless for dissecting. How to test a scissor for maximum efficiency All operating Mayo and Metzenbaum scissors should cut four layers of gauze at the tips of the blades. Smaller scissors less than 4" in length should cut at least two layers of gauze at the tips. Additionally, eye scissors should have a delicate touch when cutting. The Mayo and Metzenbaum scissors should cut with a fine, smooth feel and a minimum amount of pressure by the blades. Check the action the scissors; it should not be too tight or too loose. Check the tips (points) of the scissors. Are they too sharp? Are there burrs on the tips of the blades, especially on the Mayo and Metzenbaum scissors? When the scissors are closed, are the tips of the blades open? A scissor should both cut on the tips and feel very smooth when cutting. Needle Holders No instrument receives greater abuse than a

needle holder. It is the only instrument involving constant metal to metal contact. Many times when pliers are not available, especially to orthopedic surgeons, needle holders are used on screws, pins, bone plates, etc. How to test a Needle Holder The test is very simple. First, clamp the needle in the jaws of the needle holder. Then, lock the instrument on the second ratchet tooth. If the needle can be turned easily by hand, the instrument should be set aside for repair. When the instrument is new, it will hold securely on the first ratchet tooth for a considerable time. Needle Holders, such as a Crile Wood, Derf, or Halsey used in plastic surgery, should hold at least 6-0 suture. Eye needle holders, such as a Castroviejo or Kalt, should hold 7-0 suture. Lubricating surgical Instruments Ordinary oil or mineral oil is not permeable by steam and should never be used on surgical instruments. Neither should it be used for oiling the screw lock on scissors or the box-lock on forceps. Extensive test have shown that oil will harbor bacterial spores in box-locks even though the instruments are autoclaved. Common lubricating oil acts continuously as a collector of dust and dirt. The problems caused by indiscriminate oiling if instruments are matters of grave concern. The development of a lubricant called Instrument- Milk resulted in a dramatic break through in the science of instrument maintenance. After the InstrumentMilk dip is applied, the instruments are autoclaved. The lubricant's unique characteristics permit complete sterilization of both lubricant and instrument while lubricating qualities are fully retained. A knowledge of the operating and the testing characteristics of surgical instruments can substantially benefit many segments of the nursing profession. Instruments which are kept in optimum conditions by periodic testing, at least monthly, and which are repaired as required, produce multiple profitable gains. Surgeons save time and are able operate with unerring precision. Operating Room supervisors abide in an atmosphere of satisfaction which comes from doing an important assignment exceptionally well. Subsequently they develop and enjoy increased rapport with surgeons and gain their respect. Hospitals save money be keeping their surgical instruments in optimum condition. As with the maintenance of most technical equipment, the best maintenance is the cheapest. In consequence, the patient gains the most from the increased potential for a completely successful operation.

CORROSION OF STAINLESS STEEL SURGICAL INSTRUMENTS Corrosion of stainless steel surgical instruments is a constantly recurring problem to both the surgeons and the instrument maker. The surgeon is justly chagrined when he finds rust on his delicate hand made instruments. The blame is likely to fall on the instrument maker when no other cause is apparent. However, corrosion is not uniformly observed. In some hospital corrosion of stainless steel instruments is rarely seen, while in others, each sterilization produces a coating of corrosion. The purpose of this paper is to explore some of the causes of corrosion and to indicate what is being done by the user to minimize corrosion. There is a need for some explanation as to the choice of stainless steels used for fabricating surgical instruments. Also a question may arise as to why stainless steel should rust under any circumstances. In the usual industrial situation a manufacturer's choice of raw materials is guided by economics. He must balance desired physical properties against costs. This is not the case in the manufacture of hand made surgical instruments. Here, raw material costs are insignificant compared to labor costs so that only metallurgical properties are considered. A wide range of metallurgical properties are offered by the class of metals called stainless steel. These metals have iron and chromium in common, but contain carbon, nickel, sulfur, tungsten, manganese, molybdenum and many other elements. It is chromium which imparts the stainless quality; and in general, the more chromium present in the alloy, the more resistant it is to the corrosion. Carbon reduces the corrosion resistant effect of chromium, but it is necessary to produce hardness. Hardness is a prime consideration in instruments that require extremely sharp edges or accurate jaw approximation. It is a unhappy circumstance that there are only a few stainless steel alloys which may be hardened sufficiently to be used in the manufacturer of delicate surgical instruments. These alloys are low in chromium content and high in carbon content. They belong to the broad class known as stainless steel, but are the least corrosion resistant of the group. In order to minimize corrosion of these hardenable stainless steel alloys, special handling is required by the processor. A properly made instrument will have passed through two processing steps which increase its resistance to corrosion. In one of these steps, called passivation, the instrument is treated with nitric acid. This dissolves away any particles of carbon steel which may have been ground in during processing. All tools necessary for fabricating are of necessity made of carbon steel (regular steel). The nitric acid bath also promotes the formation of a surface coating of chromium oxide. The formation of the chromium oxide coating is usually considered the mechanism by which chromium produces resistance to corrosion in stainless steel. Polishing is the second processing step which reduces corrosion. Polishing removes sites of possible corrosion attack by producing an extremely smooth sur-

5 face upon which a continuous layer of chromium oxide may form. Surfaces which may not be effectively polished are usually the first to show corrosion. Thus, knurled handles or handles with milled grooves may rust , while the remainder if the instrument is unaffected. Even the satin-like, dull finish used to reduce glare is somewhat more prone to surface corrosion than highly polished surfaces. This surface corrosion will not penetrate deeply and usually may be removed by scrubbing with a brush and an abrasive soap. Instruments with surface corrosion can be repolished and passivated by the manufacturer to new condition. Usually, the surface corrosion does not reappear under proper maintenance thereafter. A more distressing type of corrosion is that which takes place on blades of knives, in box-locks or between the blades of scissors. In these cases the function of the instrument may be impaired. The most common causes of this type of corrosion are as follows:

•Inadequate cleaning and drying immediately

after use. •The use of corrosive sterilizing solution or too long exposure to sterilizing solution. •The use of faulty autoclave. Probably the single most important consideration in the care of surgical instruments is cleanliness. Any foreign material either organic or inorganic on the surface of hardenable stainless steel is likely to promote corrosion. Thorough cleaning is more difficult than is realized by some surgical nurses. This was shown by investigation of Allegheny Ludlum Steel Corporation to determine the specific cause of corrosion on certain surgical instruments. A microscopic examination revealed foreign material scattered over the surface of these instruments. Also chlorides were found in the corrosion products. These findings indicate that the instruments had not been thoroughly cleaned or rinsed. A good soap and rubbing is required. Often a soft brush is needed. Such as the Whisk'R Brush available from Sontec Instruments. Finally the instrument should be disassembled after use, thoroughly cleaned, and thoroughly dried before they are reassembled. Instruments of this type will corrode if they are stored with trapped moisture. A convenient method of removing corrosion products from inaccessible places is to soak the instrument in a mixture of equal parts ethyl alcohol and aqueous ammonia. After contact with this solution for about twelve hours, the corrosion products may be rinsed or lightly brushed away. This procedure is particularly useful in freeing box-locks which have frozen because of corrosion. Box-locks present a problem due to a tendency to retain sterilizing solutions and moisture; furthermore, the intersurfaces are not polished. Sterilizing solutions are a likely source of the chloride found in the corrosion products. Certain qua-

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ternary ammonium chlorides make good cold sterilizing agents as they have very strong germicidal properties as well as being detergents. The detergent property results from the molecular structure which contains a large organic group and an ionic portion. Such compounds are inherently corrosive due to the presence of the chloride ion. These materials are usually compounded with rust inhibitor which is effective for only a limited time. When cold sterilizing solutions are used, they must be replaced frequently. If corrosion still persists, the solutions should be prepared with distilled water. Corrosion during autoclaving will take place if (1) the autoclave is not operating properly, (2) corrosive materials are in contact with instruments or (3) tap water instead of distilled water is used to generate steam. Autoclaves in which a large amount of corrosion takes place should be inspected for leaking valves. Such autoclaves may not be drying the instruments adequately or may even be drawing corrosive matter back from the drain. The source of the trouble may be as remote as the laundry. Cloth used to wrap instruments to be autoclaved may contain residual detergents, bleaches or starch. These compounds can promote corrosion at the operating temperatures of the autoclave. The best material now available for the manufacturer of surgical instruments is a hardenable stainless steel. With this material, extremely fine points, sharp edges and durable sets may be fashioned into instruments. However, in obtaining hardness, some resistance to corrosion is sacrificed. Special handling by the manufacturer as well as the user indicated. In order to reduce corrosion , instruments must be thoroughly cleaned and dried, and they must not be given prolonged exposure to sterilizing solutions. Care should be taken that no corrosive materials are introduced into the autoclave and that the autoclave in functioning properly. Whenever the autoclave is suspect, distilled water should be used. When corrosion does occur in stainless steel instruments, it is usually of superficial nature. This surface corrosion may be removed by soaking in a solution of alcohol and ammonia or by repolishing by the manufacturer. Instruments used in speciality surgery are the products of a few highly skilled craftsmen. At their finest, these instruments reflect not only craftsmanship but a high degree of artistic ability in design and styling. When such instruments are give the very special care which they deserve, they will retain their beauty and function for many years.

Every hospital owns many thousands of dollars worth of surgical instruments. The care and maintenance these instruments receive is critical to their performance during surgery and to the cost containment effort of each hospital. Having made the investment in a quality product, the hospital can expect several years of use if the staff

utilizes proper technique during the use, care, and handling of its surgical instruments. Manufacture Metallurgical research has enabled instrument makers to produce accurate, long lasting surgical instruments. The steel used in most O.R. instruments is a 400 series alloy which has several useful properties. It can be brought to very sharp cutting edge and will hold this edge through continuous use. In addition, it has a high tensile strength enabling it to maintain precisely set jaw approximations. The metal is often referred to as stainless because of its corrosion resistant qualities. A chromium content of 11.5-18% gives the steel some of its stainless characteristics. However, a manufacturing step known as passivation actually provides the instrument with its corrosion resistance properties. Passivation, which follows the final polishing steps, is a chemical bath which creates an oxidized layer on the surface on the instrument. Through routine hospital use and exposure to the air this oxidation process continues, effectively maintaining and even building up a barrier to most stains and corrosive elements. Maintenance Procedures Designed and crafted to exacting specifications, instruments will perform for a reasonable number of years when the following steps are observed: Instruments should be used during surgery for their intended purpose exclusively. Misusing instruments will lead to damage that is usually not repairable. A hemostat, for example, that is used to clamp tubing can come out of alignment and quickly break. Certain compounds are highly corrosive to stainless steel and will cause serious damage despite the passivated protective surface. Instruments should never be exposed to Hydrochloric acid, Aqua regia, dilute Sulfuric acid, Iodine, or Ferric chloride. In addition the following substances should be kept away from instruments whenever possible: •Aluminum chloride •Ferrous chloride •Barium chloride •Mercury chloride •Bichloride of Mercury •Potassium Thiocyanate •Carbolic acid •Potassium permanganate •Calcium chloride •Sodium Hypochlorites •Dakin's solution •Stannous chloride •Chlorinated lime Instruments should be rinsed immediately follow-

ing contact with any of these substances. It is important to rinse instruments that have been exposed to blood and saline solutions before these substances dry. Blood will cause a stain that is difficult to remove, and saline solutions are highly corrosive. Instruments should be placed in a basin of sterile distilled water immediately following use. The box-lock portion of instruments must be kept clean and free of debris. A buildup of substance in this area will cause instruments to become stiff and eventually break. Manual cleaning should remove all visible residue, and it is essential to keep the box-locks open during any automated cleaning procedure. When cleaning, sterilizing and rinsing instruments, it is important to use solutions with a pH as near 7.0 (neutral) as possible. Distilled water is recommended rather than tap water because it is free of many compounds which exist in ordinary water. These substances alone cause stains and when tap water is combined with some detergents it will form insoluble deposits on the instruments. During Manual cleaning, avoid the use of steel wool, wire brushes and highly abrasive detergent cleaners. These will damage the instrument's protective surface and lead to corrosion. Manual cleaning will be most effective with a solution of distilled lukewarm water and a neutral pH detergent. This should be followed by a two stage rinse of distilled water, first warm then cool. The use of an ultrasonic cleaner is highly recommended. Avoid overloading the tank and always use a detergent created for the use with these machines in the suggested proportions. Thorough rinsing must follow ultrasonic cleaning in order to remove suspended particles. Never autoclave dissimilar metals together, i.e.., titanium, silver etc. Follow manufacturers specifications when using automatic washer-sterilizers. Use a freerinsing , lowsudsing detergent with a neutral pH (7.0), and do not alter prescribed cycle times. A high-sudsing detergent may clean effectively but often leave residual deposits on the instruments. Again, do not autoclave dissimilar metals together. Before instruments are wrapped for storage they must be thoroughly dry. Remaining moisture, particularly in box-locks may result in corrosion that will weaken the instrument and lead to breakage during use. The most effective method of drying instruments are in a dry heat oven, a sonic energy oven, or a hot plate. The use of water-soluble instrument lubricant is recommended. This will help keep a clean box lock moving freely and will aid in protecting the entire surface from mineral deposits. Note that ultrasonic cleaners remove all lubricants which will result in stiff box locks; hence this maintenance procedure should routinely be done after ultrasonic cleaning and before autoclaving. An effort should be made to protect sharp cutting edges and fine working tips during all maintenance pro-

7 cedures. Such as tip covers by Medi Spec. Avoid loading retractors and other heavy items on top of delicate and hollow instruments. Inspection is a vital part of proper care and maintenance. Instruments in need of repair will not perform accurately in surgery and breakage is likely to occur. Worn ratchets, loose box locks and misaligned tips can be repaired at a fraction of the cost of new instruments. Contact Sontec Instruments for information regarding a cost effective instrument repair program. Spots and Stains It is common for instruments to become stained or spotted despite the best effort of the manufacturers and the hospital staff. In nearly all cases these problems are the result of minerals being deposited upon the surface of the instruments. Adhering to proper technique during cleaning and sterilizing procedures will prevent most staining occurrences. However, they will not disappear on their own. The following section identifies the various instrument related problems hospitals may encounter. Brown Stains Detergents containing polyphosphates may dissolve copper elements in the sterilizer. This results in copper being deposited on the instruments by an electrolytic reaction. The hospital may try a different detergent or check the quantities used. Usually a dull blue or brown stain is simply a buildup of oxidation on the surface. This film is harmless and will actually protect the instrument from serious corrosion. Blue Stains Are usually the result of cold sterilization techniques. It is important to prepare the solution according to exact proportions and to change the solution when recommended. Serious corrosion may occur if the solution is used past the manufacturer's time limit. The use of distilled water and rust inhibitor in the solution will help retard discoloration. Black Stains May be the result of contact with ammonia. Many cleaning compounds contain ammonia and it will remain on the instruments unless they are well rinsed. A black stain may also be the result of amine deposits traced to the steam in the autoclaves. Solutions containing amines are often used to clean the steam lines. It is necessary to follow steam line cleaning procedures with a cycle of distilled water to remove all traces of amines from the autoclave system. Light or Dark Spots

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Are the results of slow evaporation of water condensed on the instruments. What often remains is a mineral deposit which is related to the mineral content of the water. Using distilled water for sterilizing procedures will help to eliminate the formation of these residual spots. It is also important to follow manufacturer's specific autoclave operating instructions. Spots may result, for example if the autoclave doors are opened before the steam is completely vented. An additional cause of spotting can be traced to the instrument wraps. During laundering procedures it is vital that detergents are thoroughly rinsed out and that the final rinse is prepared so that the wraps are left with a pH between 6.8 and 7.0 This will inhibit spotting during steam sterilization. Rust Deposits It is very unlikely for surgical grade steel to rust. What appears to be rust is usually residual organic matter in box locks or mineral deposits which have been baked onto the surface of the instrument. Localities where the water has a high iron content, for example, an iron deposit will result in a metallic film on the instrument. This is not the fault of the instrument and can be prevented with the use of distilled or demineralized water during cleaning procedures. Important Information The use of neutral pH detergents is vital to the maintenance of surgical instruments. Contact with acidic or alkaline solutions will remove the instruments protective barrier of chromium oxide, often leading to corrosion, pitting or breakage. There is no guarantee if the instruments are continually exposed to acidic solutions pH4 and lower or alkaline solutions pH10 and higher. Conclusion The most effective method of dealing with instrument problems is to prevent them from occurring. The use of distilled water, careful preliminary cleaning, using neutralized pH solutions, following manufacturers instructions, visual inspection, will all help to keep instruments performing accurately and cosmetically free of troublesome stains. It is important to act quickly should a problem arise. Delay will compound the problem and irreparable harm may result.

PREPARATION FOR DISINFECTION AND CLEANING Disinfection of soiled instruments not only helps to preserve the instruments themselves, but also serves to protect those persons responsible for their transportation and cleaning. Wherever possible, instruments should be disinfected and cleaned immediately after use. Any soiling left to dry will make eventual cleaning much more difficult and could result in damage to the instruments. If necessary, instruments should be taken apart, allowing the disinfectant to cover all surfaces. For disinfection of the instruments either humid heat or chemical disinfection can be used. Humid heat is preferable providing the instruments are suitable for treatment in this manner. Occasionally, corrosive caustic agents and medicines (e.g. silver nitrate, iodine preparations, albotyl and mercury components) are used in operations and for medical treatment. Remnants of these substances have to be removed immediately. Under no circumstances must instruments be stored in physiological saline solutions as prolonged contact causes pitting and rust. Undue "dropping" can cause damage to the instrument, hard metal tips on scissors may be chipped or small, delicate clamps can be deformed. In order to avoid this, carefully handle and deposit instruments after use. To avoid encrustation and corrosion, in case of removal in dry conditions and return to CSSD, the instruments must immediately be subject to machine treatment. For this treatment, deposit the instruments on suitable trays, e.g. perforated sterilizing trays. For effective cleaning, hinged instruments have to be opened (such as scissors, clamps, gouge forceps). Instruments which are subject to machine treatment have to be immersed into a combined disaffecting and cleaning agent. For removal in wet conditions and return to CSSD use only noncorrosive agents in prescribed concentrations. Water alone is not sufficient. The instruments have to be fully covered by the solutions. Instruments should never be left overnight before cleaning as the risk of causing permanent damage increases with the length of time between use and preparation. Handles and cables for HF-surgery have to be prepared like surgical instruments. Microsurgical instruments require special preparation and for this reason have to be deposited on racks or suitable holding devises. Dental materials, such as filling materials, adhering to dental instrument have to be removed directly after use. Otherwise there is the risk of hardening and/or corrosion. Rotating dental instruments such as burrs, drills, and grinding tools, have to be separated and stored in spe-

cial containers or holding devices; such instruments have to be prepared separately. If possible, surgical motors have to be dismantled in to their components immediately after use; follow the instructions of the manufacturer. Surfaces of the various parts have to be wiped with a lint free cloth, impregnated with a disinfecting and cleaning agent, or sprayed with a disinfection spray in order to avoid blockage and encrustation. Simple tools can be prepared like surgical instruments. Tubing sets for cooling liquid and spray nozzles have to be rinsed immediately with water from the rinsing bottle and checked for leakage (visual control, see chapter "inspection"). Prior to preparation, rigid endoscopes have to be dismantled according to the manufacturer's instructions. Optical equipment has to be placed in special containers. In case of flexible endoscopes , the insertion part has to be wiped with a lint free cloth immediately after use. The cloth should be soaked in instrument disinfectant which should contain either a suitable detergent component or a cleaning intensifier suitable for disinfectants. In order to avoid encrustations and blockage, the extraction channel and any other additional channels have to be rinsed with the same solution, The air/water channel has to be rinsed with water from the rinsing bottle. Prior to further processing, the leak test has to be carried out according to the instructions of the manufacturer. This allows for the detection of leaks and perforations in good time and avoids expensive subsequent damage caused by the penetration of fluids. A damaged endoscope together with a fault description has to be returned immediately to the manufacturer. Cleaning and disinfecting of endoscopes should preferably be done in automatic machines. Dismantle elastic instruments and breathing systems according to the manufacturers instructions. Cones, sealing surfaces, thread connections and valve plates have to be carefully handled and protected against mechanical damage. Prior to preparations, completely remove breathing line from the absorbers. Data readers have to be prepared only according to the manufacturer's instructions. Manual disinfecting and cleaning For manual preparations, instruments have to be immersed into a combined disinfecting and cleaning solution with proven disinfecting effect. The instructions of the manufacturer have to be strictly followed regarding concentration, temperature and induction time. Special attention has to be paid to the manufacturer's instructions with regard to material compatibility of instruments not made of high-grade steel. Use fresh disinfecting and cleaning solutions ev-

9 ery day. The following problems may occur due to using the same solutions for too long:

•Risk of corrosion due to soiling •Risk of corrosion due to increasing

concentration caused by evaporation. •Decrease if disinfecting effect due to excessive dirt concentration. Instruments with a narrow lumen (tubings, cannulae) or with cavities are generally difficult to prepare. One must, therefore, take care that the passages are free and that the inside is completely in contact with the solutions. If powdered products are used, completely dissolve the powder first. Only then should one immerse the instruments since undissolved particles may lead to clogging of the narrow lumen and discoloration of the instruments. After chemical disinfection and cleaning, the instruments must always be rinsed well under running water. Any residue has to be removed manually (no metal brushes, no scouring agents). In order to avoid water spots, a final rinsing with demineralized water is recommended. Finally, the instruments have to be dried immediately. Water on the surfaces of elastic instruments made of rubber or plastic may cause white spots to appear which can only be removed by drying. If after manual cleaning , instruments are chemically disinfected instead of being sterilized, a separate disinfectant has to be used. The instruments then must be rinsed thoroughly with sterile demineralized water. If pneumatic air used for drying, make sure that the air flows through a sterile filter. Preference should be given to manual preparation of microsurgical instruments as they are very sensitive to mechanical damage. Even then, damage is possible, e.g. when removing blood encrustations, the main causes for damage are:

•Metal brushes •Scouring agents •Too much exertion •Dropping or knocking For cleaning, it is recommended to use either lintfree soft cloths, plastic brushes or cleaning pistols. Drying with a pneumatic-air pistol is particularly safe and effective and should therefore be given preference over any other drying method. In general, dental instruments can be prepared like surgical instruments. Instructions for preparation of

10 dental instruments, recommended for separate treatment, are given as follows. Hand pieces and angled hand pieces as well as turbines must not be immersed. The outside is either cleaned with a cloth or sprayed with disinfectant. Only the methods specified by the manufacturers have to be applied for internal cleaning and care. As a result of the material used, rotating dental instruments have to be placed in special disinfecting and cleaning solutions. In order to avoid corrosion, the instruments, after quick rinsing, have to be dried at once and treated with corrosion protecting agent suitable for sterilization. In the case of ceramic-bonded or plastic-bonded grinding tools, one must first check whether the disinfecting and cleaning agents are suitable agents for these instruments. Unsuitable agents may destroy the bonding materials. Root canal instruments are sensitive to mechanical damage and, therefore , have to be prepared separately. Root canal instruments with color-anodized handles will loose their color codes when attacked by alkaline solutions. The various components of the surgical motor line have to be externally cleaned with lint-free cloth impregnated with disinfecting and cleaning agents. Soft brushes can also be used. When spraying the surfaces with disinfection spray, wipe the parts afterward with a cloth. Under no circumstances should these components be immersed. Any penetrated liquid has to be removed immediately by turning the aperture upside down. Simple tools can be prepared like surgical instruments. Rigid endoscopes have cavities and channels which are difficult to clean. Careful preparation of these instruments requires:

•Removing the seals/washers •Opening the stop cocks •Dismantling according to the manufacturer's instructions.

When immersing the endoscope into the cleaning and disinfection solutions, make sure that all air bubbles escape from the cavities by moving the instrument to and fro or by holding it in a sloped position thus guaranteeing complete wetting of the surface. Do not use metal brushes or scouring agents, but only swabs, cleaning guns and brushes with natural or plastic bristles. Use a wooden applicator with cotton wool soaked in alcohol to gently rub off any dirt on windows or glass surfaces, otherwise use a neutral detergent (hand washing liquid). Prior to preparation take off valve and caps from flexible endoscopes, thus guaranteeing thorough cleaning and flushing of the channels. For cleaning, put the

endoscope in the container filled with instrument disinfecting and cleaning agent and make sure that the surface is thoroughly wet. Clean the channels with the brush belonging to the system followed by flushing with the cleaning solution. For this purpose some manufacturers offer a hand pump. Take particular care when cleaning the distal end (optical system, Albarran lever etc.). Immediately after this pretreatment abundantly rinse the instrument inside and outside with water. Then place the flexible endoscope into the container with instrument disinfecting solution so that all channels are filled. The hand, 1.c. pump can now be used. Take care to disinfect the extraction nozzle. Soaking time and solution concentration have to be strictly observed according to the instructions of the manufacturer. After chemical disinfection, thoroughly rinse all surfaces and channels leaving no residues. To avoid water spots use demineralized water. Additional sterile filtration of the water prevents undesired recontamination. Dry the outside of the flexible endoscope with a lint-free cloth. Drying the channels should be done according to the manufacturer's instructions by using a hand pump, light source and suction pump or by means of compressed-air of max. 0.5 bar. Undesired recontamination is prevented when sterile and filtrated compressed-air is used. Elastic instruments with lockable cavities, such as bellows and breathing masks, have to be cleaned and disinfected in closed conditions thus avoiding the penetration of liquid into the cavities. To avoid damage on diaphragms and functional parts of the breathing system, no compressed air should be used for cleaning. Machine preparation allows disinfection, cleaning, after rinsing and drying without having the instrument handled. Machine disinfection and cleaning Machine preparation is usually done in the case of a dry return to CSSD. When wet removal to CSSD is the case, then either a low-foam producing disinfectant has to be used or else the instruments have to be thoroughly prewashed as foam development in the machine can considerably influence the cleaning results. This also applies for instruments having to be pretreated either in a splashing or by ultrasonic treatment because they are soiled. (e.g. owing to dried-on blood and secreta or remnants of filling material). The temperature of the inflowing water should o not exceed 45 C as higher temperatures lead to protein coagulation and cause cleaning problems. Disinfection can either be performed chemothermally or thermally. When using cleaning agents combined disinfecting and cleaning agents on it is recommended to strictly follow the instructions of the manufacturer regard-

11 ing induction time, concentration and temperature. Using the correct dosage rate does not only guarantee a perfect disinfection and cleaning result but also the most careful treatment of the material. If alkaline detergents are underdosed (false economy) there is a risk of pitting, which can be avoided at pH-values over 10.5. When acid detergents are used, corrosion may occur due to the chlorides in the water. This can be prevented by using demineralized water. With machine cleaning, special attention has to be paid to the following:

•Hinged instruments have to be opened, thus

guaranteeing thorough cleaning in the joint. •Do not overload the perforated trays so that all instruments can be well rinsed. •A thorough internal flow has to be guaranteed with instruments having long, narrow cavities (tubing, cannula, breathing systems). Use special inserts. •Place instruments in such a way that they cannot damage each other. •Place large and bulky instruments properly on the ray thus avoiding "shadows" on other instruments •Color-anodized aluminium instruments may lose their color and thus their coding function if normal machine preparation methods are used. Remnants from the cleaning phase have to be totally removed in the subsequent rinsing procedures as otherwise spotting and/or discoloration may occur. Additional use of suitable neutralizing agent improves the rinsing results. o For final rinsing a temperature of 70-90 C has proved to be best. Should corrosion occur on surgical instruments due to bad water quality, then the rinsing temperature o should be limited to 70-75 C. Corrosion, water spots and discoloration will be avoided when using demineralized water for final rinsing . No temperature limit must then be observed. When the machine operation is done without drying, then the goods have to be removed from the machine immediately after the program has finished. If drying is not sufficient, repeat it. Machine preparation for microsurgical instruments is possible if the instruments are held in place in reliable and safe manner, e.g. racks. Dental instruments can be treated like surgical instruments for machine preparation. Pay special attention to the following: •Probes and other delicate instruments have to placed in racks or holding devices to be protected against damage. •Rotating instruments like burrs, drills, milling

span.

cutters and grinding tools are suitable for machine preparation only to a limited extent. Preference should be given to an ultrasonic bath. •Root canal instruments should also be cleaned in an ultrasonic bath. •Hand pieces can be prepared in a machine only if recommended by the manufacturer; special holding devices are, however, necessary. Immediately after the end of the machine program remove any moisture using a maintenance spray recommended by the manufacturer. •Mouth mirrors may be dull due to machine treatment which will shorten their life

With the exception of simple tools and accessories, machine preparation for disinfecting and cleaning is not possible for the components of the surgical motor line. Rigid endoscopes have to be dismantled for machine preparation according to the manufacturer's instructions. Seals/washers have to be removed and stop cocks opened. Machine preparation should only be done if recommended by the manufacturer for this procedure (e.g. optical equipment). In order to avoid damage, secure the parts safely and make sure that the insides of all cavities are thoroughly flushed. Flexible endoscopes can only be processed in special automatic machines. Standard disinfecting and cleaning machines are not suitable. If endoscopes are disinfected prior to machine preparation, only use a lowfoam product as foam which develops in the machine will deteriorate the cleaning and disinfecting results. Prior to further processing, the leak test has to be carried out according to the manufacturer's instructions. This allows for the detection of leaks and perforations in good time and avoids expensive damage caused by the penetration of fluids. There are machines in which a leak test is incorporated either before or while the program is activated. A leaking endoscope has to be returned to the manufacturer together with a fault description. Standard alkaline cleaning agents may cause damage to the endoscopes, therefore, use only those products recommended as suitable by the manufacturer. Chemo-thermical processing should not exceed a temperao ture of 60 C. During machine preparation, make sure the endoscope is secured and that all external surfaces and the inside of all channels are thoroughly and reliably flushed. Final rinsing should be performed with sterile demineralized water. If, for technical reasons, this is not possible, at least water of drinking quality must be used. Subsequent to final rinsing, machine drying should be possible. Prior to storage, thoroughly dry the endoscopes.

12

Elastic instruments with lockable cavities, such as bellows, breathing masks etc. have to be cleaned and disinfected in closed conditions thus avoiding the penetration of liquid into the cavities. To avoid overstretching of the edge of the mask, remove the nipple prior to preparation, press out some air and replace the nipple. Elastic instruments, made of PVC for example, with low temperature resistance have to be disinfected, o cleaned and dried at max. 65 C. Care has to be taken with rubber instruments because imperfectly removed residues of cleaning agents lead to irreversible damage by subsequent drying and sterilization. The surface of the material depolymerizes and gets sticky. Latex-coating dissolves under blistering. Especially serious are residue not completely flushed out of functional parts of the breathing system. Furthermore, all parts have to be completely dry as remnants of moisture may lead to functional troubles. o Elastic instruments may not be dried above 95 C; higher temperatures considerably shorten their life span. Functional parts of breathing systems are specially designed by the manufacturers of either units. Preparation can, therefore, only be performed according to the manufacturer's instructions. Ultrasonic treatment Ultrasonic treatment is particularly suitable for cleaning instruments of high-grade steel. Delicate instruments (microsurgical instruments, dental instruments) can be carefully and thoroughly cleaned by ultrasonic treatment. Furthermore, ultrasonic treatment is a suitable method to effectively remove encrustations. In order to achieve optimum efficiency of the ultrasonic treatment, please observe the following when preparing a bath: •Fill the bath to the markings. •Add a suitable cleaning and/or disinfecting agent to the water •Temperature above 40oC promotes degassing and cleaning. •No protein coagulation occurs at higher temperatures if suitable cleaning agent is used. •When using disinfecting and cleaning agents make sure that the concentration and temperatures are correctly maintained. Even with a properly prepared bath, faults can arise. These can be avoided by observing some principle rules: •Instruments have to be completely covered by the cleaning solution. Non-immersed instruments will not be cleaned. •Hinged instruments, e.g. scissors, have to be

opened •Only trays which do not affect the ultrasonic treatments should be used. •Large and bulky instruments such as lead hands or kidney trays must be placed in such a way that there are no wave shadows or inactive zones. Place such items either vertically or put them on top of the other instruments. •An excessively dirty solution in the ultrasonic bath decreases the cleaning effect and increases the risk of corrosion. Depending on the frequent cies of use, the solution has to be renewed at regular intervals. •Ultrasonic treatment times of approx. 3 minutes have proved to be efficient for cleaning at frequencies of at least 35 KHz. After ultrasonic treatment, the instruments have to be thoroughly rinsed either manually or by machine. Rinsing has to be performed with clear water of at least drinking quality or, better still, with demineralized water in order to avoid water spots. The instruments should then be thoroughly dried. To avoid damage, microsurgical instruments have to be deposited on special racks. In order to avoid destruction of surfaces and soldering seams on dental instruments, no acid cement remover should be added to the ultrasonic bath. Hand pieces and turbines are not suitable for ultrasonic cleaning. As a result of the material used, rotating dental instruments have to be treated with special disinfecting and cleaning agents. Prior to ultrasonic treatments place them on special holding devices to avoid contact damage between the instruments (e.g. by sharp cutting edges, diamond grain). After a quick rinsing under running water followed by immediate drying, rotating dental instruments have to be treated with a corrosion protecting agent suitable for sterilization. Mouth mirrors can be damaged by ultrasonic treatment. Under no circumstances use ultrasonic treatments for components of the surgical motor line, with the exception of simple tools and accessories. Ultrasonic treatment is only allowed for those parts of rigid endoscopes which are suitable for this procedure according to the manufacturers's instructions (e.g. no optical systems). Flexible endoscopes are not to be treated in an ultrasonic bath. Accessories, such as valves, caps, bite rings, and forceps are suitable for ultrasonic treatment. Elastic instruments are not suitable for ultrasonic treatment as ultrasonic waves have no effect on elastic surfaces. Functional parts of the breathing system can also not be prepared in an ultrasonic bath.

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Care and maintenance Instruments with joints or ratchets have to be treated with suitable lubricating agents during the cleaning process. These lubricating agents prevent the friction of metal on metal and preserve smooth function of the instruments, thus avoiding corrosion by friction. Furthermore, constant use of such agents prevents "sticking" of the hinged parts. The care agents can either be applied manually or during the final rinsing in the machine. In any case it is indispensable that threads, joints etc. difficult to access are directly treated with each preparation. Dental instruments have to be cared for like surgical instruments with the exception of the following:

•Hand pieces, angular hand pieces as well as

turbines have a very complex internal design. Therefore, they have to be treated with special agents in accordance with the instructions of the manufacturer.

•Immediately after drying, treat all rotating

dental instruments (drills, burrs) with a corrosion protection agent, suitable for sterilization in hot air or steam.

Motor lines have to be lubricated and maintained with agents recommended by the manufacturer. Hand pieces which are not watertight have to be sprayed with special care agents for inside cleaning and lubrication. Apply a few drops of special oil into the supply channel of pneumatic surgical motor. To distribute the oil inside , run the motor for a few seconds with compressedair. Proper lubrication and maintenance of the motor line is of great importance, therefore, the manufacturers instructions must be followed. Rigid endoscopes must be lubricated. However, joints and non maintenance-free stopcocks may have to be treated with special oil or special grease according to the manufacturer's instructions. The only necessary maintenance on flexible endoscopes is to treat the valves with silicon oil before inserting them into the valve housing. Do not spray them with car agents as the propellent gases will damage the instruments. Only silicon oils and grease-free gels should be used as lubricants. Agents containing vaseline or paraffin cause swelling or softening of rubber parts. Refrain from treating elastic instruments and breathing systems with lubricants prior to sterilization. Special care and maintenance measures are prescribed by the manufacturer, should the need arise. Elastic instruments of silicon rubber may not be

treated with silicon because of swelling which makes them inoperable. Under no circumstances use paraffin agents for rubber and latex instruments; this prevents them from swelling up. Inspection After each cleaning, the instruments have to be macroscopically clean, ie. free of visible protein remnants and other contamination. Prior to functional inspection, surgical instruments with movable parts should be cooled down, thus avoiding metal friction leading to corrosion. Before carrying out functional inspection, oil any instrument with joints, ratchets or threads. Instruments with non-traumatic toothing have to be specially inspected, and, if necessary, manually reclean the non-traumatic toothing. Worn out or damaged instruments should be removed for repair or replacement. Corroded instruments should be discarded immediately as these can cause contact corrosion even on a perfect surgical instrument. Stains on surgical instruments are due to improper preparations. Cause of such stains or spots can be:

•Insufficient mechanical or manual cleaning. •Unsuitable cleaning, disinfecting and care agents.

•Failure to observe the dosage instructions for

cleaning, disinfecting or care agents. •Remnants of cleaning and disinfecting agentsinsufficient rinsing. •Poor water quality. •Residue in the sterilizing steam, when steam quality is not accordance with recommendations. •Remnants of medications, marking pens or chemo-indicators. •Procedural faults e.g. not cleaning brand-new surgical instruments prior to sterilization. These and other causes for spots on surgical instruments show the complexity and difficulty of the problems dealt with here. To facilitate tracing and finding the cause for such stains, it is recommended to cooperate with competent manufacturers. By making use of the company's service, you will not only take advantage of their practical experience but their well-equipped laboratories as well. To avoid permanent damage, instruments with remnants on the surface have to undergo a special treatment. The method of treatment is adapted to the cause of the stain. In order to avoid damage and subsequent corrosion due to metal friction, under no circumstance use metal brushes or metal sponges to remove stains. More details about causes of stains and corrosion are given in chapter

14 12.

Each surgical instrument is designed for a specific purpose. Inspection has to be carried out to ensure that they function as they should. If any doubt, a reliable manufacturer can advise you on suitable inspection methods. Especially fine and delicate instruments are inspected under the magnifying glass. In order to avoid damage during transportation, place the instruments in specially designed racks or use special holding devices to prevent them from slipping. Faultless surgical instruments should not be packed together with instruments having damaged surfaces. Older instruments with chipped chromium and/or nickel coating may cause discoloration or corrosion on high-grade surgical instruments. It is, therefore, recommended to discard such instruments or pack them separately. Handles, cables and cables for neutral electrodes for HF-surgery have to be checked for faultless function. (Caution: defective contact). It is compulsory to sort out defective parts. Prior to sterilization the surgical motor line with accessories should undergo a functional inspection according to the manufacturer's instructions. Units operating with compressed air should be checked for leaks and be given a functional inspection. Any leakage will be audible or can be found by immersing the hose into water. For checking the exhaust channel additionally connect the pneumatic surgical motor to the compressedair hose. With the motor running, leaks can be best detected in the water. Simple tools are inspected as general surgical instruments. In order to avoid damage during transportation, store the tools in special racks or place them in suitable holding devices to prevent them from slipping. The leak test for tubing sets for cooling liquid can be carried out by means of a clamp and a large syringe filled with water. Fill the tubing with water; close one end with the clamp, and insert and empty the filled syringe in to the other end. In case rigid endoscopes are used, check the additional instruments for HF-surgery for absolutely perfect installation. Exchange damaged parts. Surfaces of electrodes/loops must be free from encrustations which can be removed with fine abrasive powder. Take care that neither insulation nor clips get damaged or deformed. To avoid damage to optical systems, clean them carefully with a swab, moistened with alcohol. If this does not remove the clouding return the part to the manufacturer for inspection. Damage can be avoided by using wooden or plastic applicators, metal is not suitable. Optical wave guides and fibre-optic cables have to be checked for optical fibre breaks. To find this out, take one

end of the fibre optic cable, hold it against the light and then look into the other end. Little black spots indicate breaks in the fibres. A large number of breaks reduces the light output. Such fibre optics as well as endoscopes with surface damage and surface deformation should be sent for repair. Normally, clouding of the optical system on flexible endoscopes can be removed by using a wooden applicator (not metal) soaked in alcohol. If this does not help, return this instrument to the manufacturer for inspection. Optical fibre breaks in the optical wave guide can be seen by holding the proximal end against the light and looking into the distal end. Quite a number of breaks considerably reduce the light output. Such damaged instruments have to be returned to the manufacturer. Endoscopes with visible external damage (e.g. deformation in the insertion part or on the supply tube, overstretched angled rubber) have to be returned to the manufacturer. Flexible endoscopes are best dried while suspended and should be stored unfolded. Locks and feedreels should be loosened. The transportation case should be used for storage. Prior to every use, check all functions of the endoscope. Use only silicon oils or greaseless gels as lubricants. Under no circumstances should vaseline or lubricants containing paraffin be used as these cause softening or swelling. Breathing systems have to be inspected according to the manufacturer's instructions. Elastic instruments have to be inspected according to their function and range of use. The most important inspections are:

•Bellows have to be undamaged and airtight •Filling system of the bellows must not show any leakage.

•Lumina of catheters and probes have to be free. •Connections have to meet functional safety. •There should be no changes of design, e.g.

radius of curvature of tracheal tubes.

Elastic instruments with faults or damage have to be replaced. Frequent problems are

•Dissolvation (blister forming) •Cracked surface •Sticky surface •Hardenings •Porous surface •Discoloration

To prevent premature failure, take care that elastic instruments are stored in a dry place without being kinked or overstretched.

•Rotating dental instruments (e.g. burrs or

15

milling cutters) can be autoclaved.

•Hand pieces should, wherever possible, be o

Sterilization General Sterilization conditions as well as units have to be in conformity with valid quality standards. Follow the sterilization instructions of the manufacturer. Sterilizing accessories as well as sterilizing packings have to meet the requirements of the both the instruments as well as the sterilizing method used. Autoclaving Normally, autoclaving is performed with satuo rated water steam at 134 C. In special cases a temperature o of 121 C can be used for a longer time. Sterilization procedure has to be standard suitably for the goods to be sterilized. Sterilizing packings have to meet the valid standards with regard to quality and applicable to the procedures selected. Steam used for sterilization has to be free from any contamination and should neither impede the process nor do damage to the sterilizer of the goods to be sterilized. In order to guarantee this, meet the recommendations of pr EN 285 regarding the quality of the water in the tanks as well as the condensate, otherwise rust particles from the conducting system may cause corrosion or a high content of silicic acid may lead to discoloration of the instruments. Due to heating and cooling down during the sterilization process, a surgical instrument with a closed ratchet may suffer from tension stress which causes stress cracking in joints or deterioration of the clamping force. Therefore, such instruments have to be sterilized either in open condition or closed on the first ratchet only. The loading weight of perforated trays filled with instruments should not exceed 10kg. After sterilization, instruments have to be stored dry until used again. Instruments as well as the inner covering of sterilized goods have to be absolutely dry after having cooled down to room temperature. Excessive condensate production during sterilization is avoided by observation of the recommended maximum weight for loaded perforated trays. Drying is facilitated by wrapping the perforated trays into a cloth within the container or external paper packing. If heavy sets are unavoidable, the instruments should be distributed among several perforated trays. In addition, special measures may be necessary for drying. In general, dental instruments can be autoclaved like surgical instruments. When separate treatment for dental instruments is necessary, obey to the following instructions.

induction

autoclaved at 134 C, due to the shorter time.

•Check whether turbines are suitable for auto claving with the manufacturer.

•For mouth mirrors, refer to manufacturer's instructions.

All components of the surgical motor line, meant o for sterile application, can be autoclaved at 134 C. Refer to the manufacturer's instructions. Special instructions of the manufacturer have to be observed for storage during sterilization. Hoses for compressed-air have to be protected against pressing during sterilization. Apart from the optical system with rigid endoscopes, all endoscope parts (insert, trocar, trocar sheath, shaft, mandrel) have to be separated from each other and can then be sterilized like other surgical instruments. Sterilizing instructions from the manufacturer have to be observed for optical systems. Optical systems suitable o for autoclaving should be processed at 134 C instead of at o 121 C due to the shorter thermal stressing. Flexible endoscopes are not autoclavable due to restricted temperature compatibility. If necessary, use gas sterilization. Instruments used for endoscopy, such as clamps, catheters etc. may be autoclaved. Elastic instruments with and without bellows made of silicon and natural latex are suitable for autoclaving. Due to the shorter thermal stress, preference is o given to a processing at 134 C. Items of thermo-materials (plastic) may only be autoclaved if recommended by the manufacturer. When elastic instruments are autoclaved, take care that the cavities, e.g. edge of mask, bellows are open in order to avoid damage due to changes in pressure. Prior to sterilization, cavities closed with valve (e.g. bellow catheters) have to be sucked free of air and water by means of a syringe. Functional parts of breathing systems can be o autoclaved at max. 134 C. Cavities must not be closed in order to avoid damage to the valves. Hot-Air Sterilization When surgical instruments are hot-air sterilized, please take care to load and operate the sterilizers properly. To ensure safe sterilization, the temperature o o should not be below 180 C but should not exceed 200 C as this may cause structural changes leading to irreversable damage, especially as far as microsurgical instrument are concerned. Instruments with parts of rubber, plastic, or textile as well as plastic-coated instruments and handles

16

for electrodes are not suitable for hot-air sterilization. The general use of lubricating agents should be omitted prior to hot air sterilization. Only oil the joints and ratchets of surgical instruments. Dental instruments can generally be sterilized like surgical instruments. When separate treatments for dental instruments is necessary, obey to the following instructions:

•Temperature should not exceed 180oC when sterilizing hand pieces.

•Turbines are not suitable for hot-air sterilization. •Burrs and milling cutters must not be sterilized o

at a temperature exceeding 180 C in order to avoid softening.

•The sterilizing of mouth mirrors has to be

carried out in accordance with the manufacturers instructions.

Components of the motor line are only partly suitable for hot-air sterilization, due to the various materials used. Rigid endoscopes are not suitable for hot-air sterilization. Flexible endoscopes are not suitable for hot-air sterilization. Elastic instruments are not suitable for hot-air sterilization. Breathing systems are not suitable for hot-air sterilization. Gas Sterilization Gas sterilization should only be used when no other method is suitable. Components of motor line should only be gas sterilized when explicitly recommended by the manufacturer. Optical systems of rigid endoscopes may be gas sterilized, however, follow the instructions of the manufacturer. Flexible endoscopes can be gas sterilized at a temo perature limit of 60 C. Use higher temperatures only when indicated by the manufacturer. For gas sterilization, the flexible endoscope is packed in a transparent sterilizing hose allowing a curvature diameter of at least 30cm. It is very important to make sure that the venting cap is adapted to the supply connector as otherwise irreversible damage will occur. To ensure protection against mechanical damage, the sealed flexible endoscope is put into a wire basket belonging to the gas sterilizer. Again, pay attention that the curvature diameter is not less than 30cm. Goods sterilized with ethylene oxide require sufficient airing times before being used again. Depending on the goods sterilized and on available airing conditions, such airing times can differ considerably. Reliable airing times

can be given only by the manufacturer of endoscopes. After airing, flexible endoscopes should be stored in an extended position. Elastic instruments of thermolabile plastic are not autoclavable but can be gas sterilized if the manufacturer gives instructions about a suitable procedure. Elastic instruments of rubber and functional parts of breathing systems do not have to be gas sterilized; use autoclaving. Treatment of brand new instruments Packings of brand-new instruments have to be removed and instruments have to be stored in dry rooms, open to air. Temperature fluctuations may otherwise lead to condensation within the plastic packing and thus corrosion. Under no circumstances store instruments in cupboards or rooms where chemicals are kept which can produce corrosion vapors. Prior to first use, brand-new instruments have to be prepared. First remove any protective caps or foils. Cleaning, rinsing, lubrication, inspection and sterilization have to be carried out according to the procedures previously described. Prior to the first preparation, microsurgical instruments have to be placed in racks or holding devices to avoid damage. Elastic instruments have to be kept in their original packing and stored in a dry, cool and dark place. When ordering supply, please keep in mind that in addition to wear through use, elastic instruments are prone to aging even when in storage. Functional parts of the breathing system frequently contains valves or membranes which can get sticky when stored for a longer period. Such valves or membranes have to be tested and operated before being put to use. Special information

•By following these instructions properly, there

is no difference in the preparation of instruments with a mirror finish or matte surface. •These instructions do not refer to disposable items •Instruments and cables with optical waveguides can generally be prepared like surgical instruments, if the manufacturers have not given other instructions. Only hot-air sterilization and ultrasonic baths cannot be used. •Fibre-optic cables should not be bent, nor coiled too tightly. •Cables and handles for HF-surgery can be

machine prepared and are autoclavable. For all other preparation processes, refer to the instructions of the manufacturer. Water for preparation Instruments must have certain characteristics in order to fulfill their function (e.g. cutting ability of scissors, clamping force of clamps and forceps). Only a very limited number of steels meet these requirements. Unfavorable water composition can, therefore, have a detrimental effect on such steels. Consequently, the quality of water must be taken into account when planning the sanitary installations. Ordinary water contains dissolved salts. The amount of salts contained varies depending on the water purification process. Evaporation of water leaves remnants of salty encrustations (lime). Of all water components, chlorides have to be regarded as the most potentially damaging because in higher concentrations they cause pitting on instruments. The relationship between chloride content in the water and pitting are not predictable in some cases. In general, the danger of chloride induced pitting rises with:

•Increasing chloride content •Increasing temperature •Decreasing pH-value •Longer induction time •Rougher instrument surface •Insufficient drying Experience shows that with a chloride content up to approx. 129mg/1 (corresponding to 200mg/1 NaC1= sodium chloride) the possibility of pitting is low but rises rapidly with increasing chloride content. Low concentration of other components can cause brown, blue, grey-black, or rainbow colored discoloration. Such discoloration can be caused by contact with the elements iron, copper, manganese, magnesium and silicon in the water. Generally, there is no corrosion. By immersing or rubbing the instruments with suitable products containing acid (follow the instructions of the manufacturer) such decolorization can be removed to a great extent. In addition to the natural water components, sometimes there are rust particles in the water. Almost always, such rust comes from corroded piping systems. When preparing the instruments, such rust particles deposit on the goods and cause rust spots (extraneous rust) followed by corrosion. Make it a basic rule to use demineralized water for final rinsing. Even when using an ion exchange for demineralization, tarnishing can occur due to penetration of

17 silicic acid. The remedy is in-time regeneration of the exchanger-consult an expert. Materials When producing surgical, microsurgical, and dental instruments, the manufacturer will use the materials most suitable for the purpose for which the instrument is intended. In most cases, the demands for high elastic and toughness, good cutting ability and high wear resistance, together with best possible corrosion resistance can only be answered by using metal materials for surgical instruments. Therefore, stainless and hardenable chromium steels with a chromium content of approx. 13% are used. Instrument characteristics, such as smooth and homogeneous surface, a matte or mirror finish, and a hardened condition can be achieved with steels. The user has to observe, however, that these instrument steels, listed in national (DIN) and international (ISO) standards, are generally resistant to chemical and thermal stress as occurring in doctor's practices and hospitals, but are, on the other hand, very sensitive to stress corrosion and chloride induced pitting. Apart from the hardenable stainless chromium steels, non-hardenable chromium steels with modified chromium content and rust and acid resistant chromiumnickel steels are used. The use of the latter steels is limited to certain instrument types due to restricted mechanical properties. For the manufacturer of rigid and flexible endoscopes of all kinds, chromium steels are hardly taken into consideration. Due to the application technique and design of the endoscopes, the greatest variety of materials is used. Here are some of the most important ones:

•Rust and acid resistant chromium-nickel steels. •Surface treated non-ferrous heavy metal alloy e.g. brass, chromium-nickel plated. •Light metals (e,g, anodized aluminium). •Non-corrosion resistant steels, e.g. for lacquered modules and single parts. •Glass for optical systems. •Ceramic •Cement and adhesives. •Plastic and rubber.

The combination of these heterogenous materials is, with regard to the preparation of the units, a weakness in the chain of materials. It may, therefore, be possible that the special processing, deviating from the ordinary preparation processes, may become necessary. When in doubt, ask the manufacturer should he not have given already recommendations for use. Elastic instruments and breathing systems also

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demand a wide variety of materials, similar to those used for endoscope, i.e. rubber, latex, and silicon. The full scale of materiels dealt with in this brochure is used for the motor line as far as design, structure and manufacturing is concerned. Stainless, hardenable chromium steels are used for burrs, drills, milling cutters, saw blades and gearing parts as well as sterilizable plastic materials for handles, switches, gearing parts or cable and hoses. Special preparation methods may be necessary for enamelled housing of the unalloyed steel sheet, lacquered color codes for identification of the gearing on hand pieces or anodized housing of aluminium for hand pieces and angular hand pieces. Heavily used flexible cables, bearings and gearing parts of stainless, but also of non-stainless heat-treatable steels as well as bronze materials require special preparation and lubrication methods. Should any questions or doubt arise, it is strongly recommended to ask the advise of the manufacturers. Due to chemical or thermical influences during use, preparation or sterilization, all instruments and units, dealt with in this brochure, can experience surface changes, corrosion or aging. Surface changes, corrosion and aging Surface changes are visible appearances. Normally, this refers to all kinds of instruments and units, independent of the material. In particular this refers to removable residues such as adhering or already encrusted remnants from operations or other soilings. Through cleaning using special basic cleaning agents, such as surface changes, can be completely removed without doing any harm to the instruments. Quite often, yellow-brown, to dark-brown blisterlike spots show on sterilized instruments and units made of metal and are mistaken as rust. In most cases, such residue can contain high degrees on chlorides which then lead to chloride induced pitting on parts made of stainless steel if the spots are not removed immediately. Such residues are usually found on those places with difficult access for cleaning. Annealing colors, black tints or water spots appear mostly on metallic instruments and units and hardly ever on rubber or plastic products. In general, discolorations do not show clearly defined edges. Flowing color shadings or deep and uniform staining (black colorings) can appear. Discoloration does not permanently damage or destroy the instrument or units. Causes can either be the be the bad quality of water used for cleaning or autoclaving as well as inadequate machine cleaning and installations for steam supply. The only remedy is to check the technical equipment in the house installation, in cooperation with the manufacturer of cleaning, sterilization and steam supply plants and also together with the manufacturer disinfectants or cleaning agents. Water Spots are similar in appearance. However

normally they show sharply defined edges and are caused by too high a concentration of minerals e.g. lime or organic substance in rinsing water or sterilization steam. The remedy is to use demineralized water for final rinsing and pure steam. Overloaded sterilizing plants may cause increased condensation and consequently increase stains during sterilization, therefore, avoid overloading. The term corrosion refers to metallic material only. Corrosion is specific to materials and occurs on various metals in different appearances. Almost always the corrosion leads to permanent damage or even destruction of instruments and units. Any kind of corrosion on surgical instruments and units can only occur due to inductions of water, aqueous solutions or steam. Following is a description of the most important kinds of corrosion and their effects, in the sequence of their frequency of appearance. Pitting corrosion refers only to metallic materials. Unfortunately, pitting can also appear on stainless steels of which not only most surgical instruments are made, but also endoscopes, (although fewer in number), surgical motor line and parts of breathing systems. With all types of steel, pitting is mainly caused by active chlorides (chloride induced pitting). Other halide ions (iodides, bromides) have the same effect. Nonferrous metals such as copper and aluminium alloys can also be damaged by pitting, however, other electrochemical causes may also be the reason. Pitting means that holes developed on the surface of the instruments. These holes indicate rust and, with continuous corrosion, get rapidly bigger and destroy the instruments within a short time. Pitting can only be avoided in instruments having been in contact with chlorides or other halide ions are cleaned immediately after use. Please note that operation debris also contains chlorides which leads to pitting should these remnants stay long enough on the instruments. Attention also has to be paid to the quality of water used for cleaning and disinfection, especially with regard to its chloride content. Stress Corrosion cracking normally occurs only in steels used for surgical instruments; it can have considerable effects on the life span of the instruments. The cause of this type of corrosion can lie either in the manufacturing process or in incorrect handling. In order to avoid damage, it is absolutely necessary that during the complete cleaning phase, all instruments are kept in open condition. In order to avoid damage in such as stress cracks in the joints and a reduction of clamping force, when sterilizing such instruments, only close the first ratchet. This prevents stress forces from occurring while heating and cooling during the sterilizing process. Even tiny quantities of chloride in the water may favor the forming of stress corrosion cracking. Fretting and crevice corrosion have almost simi-

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lar causes. Both types of corrosion occur in narrow joints due to chemical or mechanical destruction of the natural passive coating of the high quality steel. In addition, due to the lack of sufficient lubrication, metallic abrasion occurs in joint crevices and hinders smooth action of the instrument. In both cases, and together with humidity, rust blisters occur in the crevices. Contact corrosion can occasionally be observed when surgical instruments are machine cleaned. Metallic contact of instruments and unfavorable cleaning and rinsing conditions, e.g. tap water containing chlorides, can cause rust. Particularly severe contact corrosion occurs if stainless steel instruments get in contact with non-stainless goods, such as needles, cutters, etc. Chromium-plated instruments with chipped surfaces also cause contact corrosion. With Surface corrosion the total surface of a metal part is relatively uniformly attacked by chemical or other electrochemical influences. The surface can show parts which differ in color to undamaged surfaces. This corrosion takes the form of rust where steels are concerned. Surface corrosion hardly ever occurs with instrument made of stainless steel. Instruments, trays and containers of anodized aluminium ask for a preparation method suitable for the material. Acid or alkaline solutions may cause laminar corrosion which, especially on colored parts, causes, "bleaching" Instruments and units of stainless steel or nonferrous metal, protected by galvanically applied coatings, show surface corrosion only with damaged protective coatings. Any kind of corrosion leads to rust on steels. Rust particles are transferred from one instrument to another during disinfection, cleaning or sterilizing, so this transferred rust causes resultant corrosion on the second instrument. If corroding instruments are not separated, further preparation processes promote rust formation on other instruments. Sterilizing steam from rusty steam supply pipes may transport rust particles into the sterilizer. This extraneous rust deposits itself on the inside of the sterilizing chamber, on the packings, on instrument surfaces. This extraneous rust also leads to resultant corrosion on instruments. Aging mainly refers to rubber and latex materials used for flexible instruments, such as parts of endoscopes and breathing systems. Aging is a slow going antral process occurring also during storing. The aging process is accelerated by the induction of dry heat with temperatures above 80oC, by stretching and overstretching when storing as well as by the action of light (e.g. sunlight, UV beams). Aging is visible on rubber by decolorization (brownish) or brittleness (cracks on the surface). Plastic also ages: it gets hard and becomes yellow. However, silicon cautchouc,

also called silicon elastomer, does not age. Another result of aging on rubber, latex and plastic is the so-called swelling which is caused by the penetration of liquid or gases to the surfaces. Swelling can be reversible and occurs only temporarily by the induction of volatile solutions or propellent gases of sprays. This also applies if rubber and certain plastic get into contact with either gases such as halothane. Irreversible swelling, however, occurs by contact with nonvolatile oils (paraffin), vaseline and unsuitable disinfectants (e.g. phenol derivates). Silicon cautchouc reacts reversibly on propellent gases of sprays and either gases; irreversibly on silicon oils and solvents. Typical signs of swelling are soft sticky surfaces as well as damage to thin-walled instrument parts. Brief Information •Brand-new instruments have to be cleaned prior to the first sterilization •Instructions for use have to be strictly observed. •Strictly adhere to dosage, induction, time and temperature for disinfecting and cleaning. •Used instruments have to be treated as soon as possible. •Use proper accessories for cleaning •Do not overload washing machines and ultra sound devises. Avoid rinsing shadows as well as wave shadows. •Never use metal brushes or metal sponges for manual cleaning. •Rinse thoroughly and carefully after cleaning. If possible, use demineralized water. •Dry sufficiently after rinsing. •Worn corroded, deformed, porous or otherwise damaged instruments have to be sorted out. •Each preparation of instruments with joints needs a treatment with a care agent based on paraffin oil (this does not apply to flexible endoscopes and accessories). •Prior to sterilization, only close the first ratchet on the instruments. •Sterilization is no substitute for cleanliness.

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I.

CLEANING, STERILIZATION & MAINTENANCE Rinsing Immediately after surgery, rinse instruments under warm (hot water. Rinse should remove all blood, body fluids and tissue. Cleaning If not done immediately after rinsing, instruments should be submerged in a solution of water and neutral PH (7) detergent. Ultrasonic cleaning For micro and eye instruments, use manual cleaning (step C). Instruments should be processed in the cleaner for the full recommended cycle time (usually 5 to 10 min.). Place instruments in a open position into the ultrasonic cleaner. Make sure that "sharps" (scissors, knives, osteotomes, etc.) blades do not touch other instruments. All instruments have to be fully submerged. Do not place dissimilar metals (stainless, copper, chrome plated, etc.) in the same cleaning cycle. Change solutions frequently at least as often as manufactures recommends. Rinse instrument after ultrasonic cleaning with water to remove ultrasonic cleaning solution. Automatic Washer Sterilizers Follow manufactures recommendations but make sure instruments are lubricated after last rinse cycle and before sterilization cycle. Manual Cleaning Most instrument manufacturers recommend ultrasonic cleaning as the best and most effective way to clean surgical instruments, particulary those with hinges, locks and other moving parts. If ultrasonic cleaning is not available, observe the following steps:

Use stiff plastic brushes (nylon, etc.). Do not use steel wool or wire brushes except specially recommended stainless steel wire brushes for instruments such as bone files, or on stained areas in knurled handles. II. Use only neutral PH (7) detergents because, if not rinsed off properly , low PH detergents will cause breakdown of stainless protective surface and black staining. High PH detergents will cause surface deposit of brown stain, which will also interfere with smooth operation of the instrument. III. Brush delicate instruments carefully and, if possible, handle them totally separate from general instruments. IV. Make sure all instrument surfaces are visibly clean and free from stains and tissue. This is a good time to inspect each instrument for proper function and condition. Check and make sure that: Scissors blades glide smoothly all the way (they must not be loose in the closed position). Test scissors by cutting into thin gauze. Three quarter of length of blade should cut all the way to the scissors tip, and not hang up. Forceps (pickups) have properly aligned tips. Hemostats and Needleholders do not show light between the jaws, lock and unlock easily, joints are not to loose. Check Needleholders for wear on jaw surfaces. Suction tubes are cleaned inside. Retractors function properly. Osteotomes and knives have sharp undamaged blades. Test Biopsy Punches by cutting tissue paper. Punches should produce a clean cutout, without hanging or tearing. V. After scrubbing, rinse instrument thoroughly under running water. While rinsing open and close scissors, hemostats, needleholders and other hinged instruments to make sure that the hinge areas are rinsed out, as well as the outside of the instruments. After Cleaning If instruments are to be stored, let them air dry and store in a clean and dry environment. Autoclaving If instruments are to be reused or autoclaved: A. Lubricate all instruments which have any "metal to metal" action such as scissors, hemostats, needleholders, self retaining retractors, etc. Recommended surgical lubricants such as instrument milk are best. Do not use WD-40 oil or other industrial lubricants.

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B. Put instruments up for autoclaving either individually or in sets. Individual instruments Disposable paper or plastic pouches are ideal. Make sure you use a wide enough pouch (4" or wider) for instruments with ratchet lock such as needleholders and hemostats so the instrument can be sterilized in an open (unlocked) position. Instrument Sets Unlock all instruments and sterilize them, in an open position. Place heavy instruments on bottom of set (when two layers are required). Never lock an instrument during autoclaving. It will not be sterile as steam cannot reach the metal to metal surfaces. The Instrument will develop cracks in hinge areas because of heat expansion during autoclave cycle.

Do not overload autoclave chamber, as pockets may form that do not permit steam penetration. Place towel on bottom of pan to absorb excess moisture during autoclaving. This will reduce the chances of getting "Wet Paks". Make sure the towels used in sterilization of instruments have no detergent residue and are neutral PH (7) if immersed in water. This can be real problem as laundries frequently use inexpensive but high PH (9-13) detergents and do not properly rinse out or neutralize those detergents in the final wash/rinse cycle. Also, sometimes bleaches such as Clorox are added and are not neutralized. CAUTION-At the end of the autoclave cyclebefore the drying cycle-unlock autoclave door and open it 3 no more than a crack (about /4"). Then run dry cycle for the period recommended by the autoclave manufacturer. If the autoclave door is open fully before the drying cycle, cold room air will rush into the chamber, causing condensation on the instruments. This will result in water stains on instruments and also cause wet packs. If you have any unusual staining on your instruments during sterilization, contact your local instrument representative. Cold Sterilization Most cold sterilization solutions render instruments sterile only after a 10 hour immersion. This prolonged chemical action can be more detrimental to surgical instruments then the usual 20 minute autoclave cycle. if the instruments need to be "disinfected" only, cold sterilization is okay as disinfection will take place in only 10 minutes. But keep in mind the difference between: STERILE -an absolute term (no living organism survives). And DISINFECTED- basically clean. Always use the proper sterilization/cleaning technique to render the instruments in the required condition for use.

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COMPREHENSIVE SURGICAL INSTRUMENT CARE

Cleanliness, lubrication, correct handling and storage procedures will insure an instrument's proper performance. Additionally, inspection, troubleshooting, and a professional instrument maintenance program can actually lengthen the serviceable life of your surgical instrument. To that end, the following instrument care habits are recommended. Use of short cuts in instrument care can lead to rust, corrosion, stains and spotting. Corrosion, the gradual wearing away of material, will eventually impair the function of an instrument. The most common causes are linked to: •Inadequate cleaning and drying after use •Corrosive chemicals or sterilizing solutions •Use of ordinary tap water rather than distilled or softened water in cleaning process •Laundry detergent residue remaining in operating room linens •Harsh detergents •Malfunctioning autoclave Corrosion also will appear on knurled or grooved surfaces. Glare-reducing satin finishes are more prone to corrosion than mirror finishes. This type of corrosion does not penetrate deeply and can easily be removed with simple brush and detergent scrub. Should this procedure fail, an instrument can be repolished. Autoclaving causes oxidation of surgical instruments while they are exposed to air, moisture and heat. Water left in the box locks is another offender. Never autoclave dissimilar metals together, i.e., titanium, silver etc. Light and dark-colored spots are caused by the slow evaporation of condensation on instruments. Traced to mineral residue, such spots can be prevented by following the autoclave manufacturer's directions carefully and using distilled or demineralized water for all cleaning procedures and solution preparation. Rust-colored film is particularly prevalent in new hospitals due to foreign matter inside steam pipes during installation. Unfortunately, nothing can be done, but the situation is temporary. Bluish-grey stains are indicative of cold sterilizing solutions. Following manufacturer's directions explicitly will remedy the situation. A brownish stain is a chromic oxide film which forms on stainless steel when dishwashing compounds are used by hospitals. Frequently experimentation with another compound used successfully within the community will minimize discoloration, Ad-

ditionally, such compounds should be measured accurately and sterilizers filled with cold water. Purplish-black stains indicate exposure to ammonia; thorough rinsing after use and cleaning in the usual manner should eliminate this stain. Rust deposits present a unique problem that they can not be rinsed off. Once an instrument surface has been rusted or pitted, it is far more susceptible to further corrosion. Fortunately, passivation and repolishing can return the instrument to a like-new condition. Prevention of such rust deposits and pitting can be aided by not sterilizing together metals of dissimilar composition. For example, the sterilizer's electrolytic action can carry carbon particles from imperfectly chrome-plated instruments and deposit them on a stainless steel instruments causing a rusty appearance. Sterilize different metals separately, replace chrome-plated instruments with stainless steel counterparts. •Cleanliness: All instruments should be thoroughly cleaned immediately after use. Never allow blood in a box-lock or debris to dry on the instruments. Baked on blood in a box lock or crevice can result in corrosion and subsequent cracking under stress. Therefore, box locks should be opened and instruments with removable parts should be disassembled. Cleaning solutions with a natural pH level (7.0 to 8.5) are recommended. An extremely alkaline detergent (higher than 9.0) may stain and might cause breaks; an extremely acid detergent (lower than 6.0) may cause an instrument to pit. Washing-sterilizer's are ideally suited for washing and terminally sterilizing soiled instruments. However, it is imperative that the sterilizer itself be cleaned and functioning properly. Hospitals in the hardwater areas should implement a water softening or demineralizing system. Surgical wrappings must be free of any laundry detergent residue. Ultrasound provides a speedy and complete method for instrument cleaning. Although an ultrasonic cleaner removes up to 90% of the soil, it does not preempt the need for sterilization. Caution: Microsurgical instruments must not come in contact with one another during ultrasonic cleaning. The units vibration may cause premature wear of their precision tips. Never clean dissimilar metals together i.e., titanium, silver etc. •Lubrication: It is recommended that instruments are lubricated after every cleaning process to guard against mineral deposits and other water system impurities which may lead to stains, rust and corrosion. Also prior vigorous cleaning removes all lubrication which may result in "frozen" box

locks. To impede the growth of bacteria in the lubricant wash, only antimicrobial, water-soluble lubricants recommended. Instrument milk baths produce excellent results. •Correct Handling: Proper usage helps insure instruments will function well when they are needed. To avoid unnecessary instrument abuse, we strongly urge that instruments be used only for specifically designed purpose. Needle Holders Should never be used as pliers. This will lead to improper alignment of the jaws. Always match the needle holder to the size needle being used.

Scissors Are particularly subject to abuse. Misuse can easily dull or chip the cutting edge and misalign the blades. Eye scissors are extremely delicate and must be treated accordingly.

Rinse & Sterilization During rinse and sterilization, never allow delicate instruments to be laid in a steel pan or on a tray or to be bumped against one another. Always lay instruments on a towel or specially designed rubber or foam tray. After Use Put protective tips over the ends of delicate instruments. Available from Sontec. Meticulous care during surgery will also prolong the life of the surgical instruments. Although blood and saline are the most common causes of corrosion and pitting, instrument contact with the following solutions should be avoided if possible: •Aluminum chloride •Mercury salts •Barium chloride •Phenol •Carbolic acid •Potassium Permanganate

23 •Chlorinated lime •Dakin's solution •Sodium hypochlorite •Ferrous chloride •Stannus chloride •LYSOL •Tartaric acid •Mercury bichloride Exposure to the following solutions is extremely detrimental: •Aqua regia (a mix of nitric and hydrochloric acids) •Ferric chloride •Diluted sulfuric acid •Hydrochloric acid •Iodine (not to exceed 1 hour) Instrument counts guard both patients and instruments and reduce the instruments` chance of an unnecessary trip to the laundry. •Storage: Well defined storage procedures reduce the chance of bent, broken and dulled instruments. Do not bounce, drop or weigh down instruments. Treat them gently; handle them individually or in small quantities. Masses of entangled instruments cause damage. Do not force a large instrument into a small tray. Place heavier instruments in the tray bottom with the lighter instruments on the top. Instruments should be arranged accordingly: A. Place ring-handled instruments on a holder to keep them in an open position. B. Instruments with curved jaws should all point in the same direction. C. In order that the edges do not come in contact with another instrument, scissors should be kept separate on the rack. D. Cupped instruments should be arranged so that water does not collect in them. E. Use specially designed racks for microsurgical instruments. •Inspection: In addition to being completely clean and freemoving to insure proper function and sterilization, instruments must be inspected prior to packaging for reuse. Hinged instruments should be inspected for alignment of jaws, meshing of teeth and stiff or cracked joints. Rachets should close easily and firmly. To test rachets clamp the instrument on the first tooth. Holding the instru-

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ment at the box, tap the rachet end against a solid object. Repair is required if the instrument springs open. Close instrument to test its tension, when jaws touch, a space of 1 1 /16" to /8" should exist between rachet teeth of each shank. Ring-handled instruments can be tested by holding one handle in each hand. Open instrument and try to wiggle it. If the box lock is very loose, jaw misalignment will occur. Scissor blades should be inspected for burrs. If a needle which is clamped in the jaws of a needle holder locked on the second ratchet tooth can easily be turned by hand, the jaws need replacement and/or aligning and should be sent for repair. Elevated heat temperatures weaken stress points and can actually change molecular structures of the metal. This change weakens and dulls instruments resulting in their continual diminished performance. Be on the lookout for weakened stress points. •Maintenance Program After repeated use and sterilization, instruments will show signs of wear. They will become misaligned, stiff from metal fatigue, dulled and chipped. When they will no longer function properly, they will either need professional repair or replacement.

ments but also precludes unnecessary repairs and unwarranted replacements.

MICRO-INSTRUMENT CLEANING AND CARE GUIDE Protect your investment. Microsurgical instruments are fine, delicate and precise. They require correct care in cleaning, drying, lubrication and storage. Even the finest stainless steel really is highly corrosion-resistant, and is still subject to water spotting, staining and eventual rust. Take care of your micro and regular instruments and devices with these facts in mind. During and after Surgery Deposit used instruments only on a cloth or, better yet on a surface covered with gauze or disposable wrap free of soap, detergent and hard mineral deposits. Do not put "micros" together with heavier instruments. •Neutral Disinfecting Solution Immersion: Such temporary immersion should be done after use only if immediate cleaning is not possible. Do not soak instruments overnight, that is the worst thing you can do especially with microsurgical instruments. Do not mix "micros" and bigger instruments. When preparing cleaning or disinfecting solutions strictly observe the manufacturer's instructions. Cleaning

Because repairs can be costly, a specifically scheduled preventive maintenance program based on usage turn is the best alternative. Particular steps include: •Inspection and evaluation •Re-passivation •Clean and lubricate •Replacement of worn and missing parts ( tungsten carbide inserts, lost screws, cracked springs.) •Restoration of finish ( grind out scratches and gouges and repolish.) •Sharpening •Final adjustment to insure an instrument works easily and is properly aligned. Implementing the above program restores your instruments to surgical grade quality before major repairs and/or possible replacement becomes necessary. Although your instrument repair cost may rise, your new instrument cost will decline over the long run, an important factor to consider in the present economy. A preventive maintenance program not only is an investment in lengthening the life of your surgical instru-

Micro-instruments should be cleaned gently and absolutely thoroughly one at a time immediately after use, preferably by hand with a soft cloth or a very soft brush, to remove all blood, debris and most especially saline solution. Do not use metal brushes or steel wool. Avoid excessive pressure and instrument-to-instrument contact. Never allow blood or debris to dry on instruments. Cakedon or baked-on blood in a box lock or crevice can result in corrosion and subsequent cracking under stress. When cleaning, box locks, joints and catches should be opened and removable parts disassembled. Cleaning solutions with neutral pH level (7.0 to 8.5) are recommended. An extremely alkaline detergent (9.0 or more) may cause staining. A very acid solution (6.0 or lower) may result in pitting and stress corrosion. Do not use scouring agents or abrasives. Calgon has two popular products: "Manu-Klenz" for washing by hand and "Instru-Klenz" for machines, as ultrasonic cleaners. There are other good cleaners. Change cleaning solutions often to keep suspended soil at a minimum. Ultra sonic cleaners provide a speedy yet gentle almost complete system for cleaning micro-instruments. A small office unit may be appropriate for your needs. The ultrasonic cleaner must be clean and functioning properly.

Hard water should be avoided by prior softening or demineralizing. Side by side placement of the instrument is best, not on top of one another. Treatment with ultrasonic waves must be as short as possible. An ultrasonic cleaner removes up to 90% of the soil, but further washing and sterilizing is still required. Follow manufacturer's instructions as to cleaning solution and procedure. Washer-Sterilizers are not recommended for micro-instruments. The agitation may damage delicate instruments. Standard instruments can survive the turbulence. Non-micro instruments can be cleaned well and be semi or terminally sterilized in these units. The units must be clean and functioning properly. Make sure the ejector is not fouled, which may lead to the formation of detergent scale. Hard water should be avoided by prior softening or demineralizing. Autoclaves are better for terminal sterilization. Rinsing After cleaning of type, rinse the instruments thoroughly in distilled water to remove any residue. If distilled water is not available, then rinse in cold or warm running water. Drying Use a soft, absorbent non-fibrous cloth. Hot air is acceptable. Many doctors use hair dryers in their offices. Knurled or grooved surfaces and glare-reducing satin finishes (which are intentionally micro-pitted) are more prone to corrosion then mirror finishes. However, satin finishes are a virtual necessity when operating in a highlylighted field under a microscope. Exercise especial care that box locks, crevices, blades and knurled, grooved and satin-finished instruments are dried thoroughly. Lubrication This step is most important after cleaning, rinsing and thorough drying to avoid "frozen" box locks, staining and corrosion caused by mineral deposits and other water system impurities. Remember that vigorous cleaning removes prior lubrication, so it must be replaced. Only antimicrobial, water-soluble lubricants should be used. "Instrument Milk" is widely used. Follow the manufacturer's instructions carefully. Machine and mineral oils as well as silicones become gum-like with age and therefore are to be avoided. The gum formation may trap germ spores and inhibit complete sterilization. Assembly After lubrication the instruments should be reassembled and placed in their respective storage trays. Use specially-designed microsurgical racks for you micro-instruments. Treat your instruments sensibly and with gentle tender loving care. Handle them individually. Masses of

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entangled instruments cause damage. Do not cram them in to undersized tray compartments. Place heavier instruments in the tray bottom with lighter ones on top. Ringhandled instruments should be placed on a holder to keep them in a open position. Curved jaws should all point in the same direction, so they do not touch. Especially avoid that scissor tips and edges come in contact with anything. Keep scissors in a separate rack. Water should not be allowed to collect in cupped instruments. Sterilization

You can either sterilize terminally or semi-terminally, sterilizing again just prior to the next surgical use of the instrument and devices. Autoclaves, steam or gas, are used for terminal sterilization. Before placing your instrument in the autoclave make absolutely certain that they are clean of soil, blood, debris, soap, detergent, bleach, starch, all of which can leave harmful deposits. It is most important to follow the manufacturer's instructions for cleaning, care and maintenance of all equipment. A dirty malfunctioning autoclave can be the source of many problems. Do not exceed recommended temperature, as this may cause rapid deterioration of the instrument. Never autoclave dissimilar metals together, i.e., titanium, silver etc. Preheat instrument in the sterilizer chamber before sterilization to avoid the problem of residue-laden condensation forming on the cold instruments, which can lead to subsequent staining. Also after sterilization, do not open the autoclave too quickly so a blast of cold air causes steam condensation and residue deposit on the instruments. Wrapping can be done with either cloth or disposal wraps. Cloth wraps must be free of any laundry detergents, soap or hard water residue. Disposable wraps are free of contaminants, and therefore may be preferable. Unless thoroughly vacuum dried, wraps could retain moisture which leads to stainless and rust. Therefore, it may be best not use wraps. Sealing This can be done with either cloth or paper dust covers. Cloth covers may provide protection up to 30 days. Paper dust covers may protect up to six months. Resterilization before surgical use is indicated for respective longer storage. Clogged Cannula Use Enzyme tablets of the type used for contact lenses to unclog deposit proteins and other impurities. Cold Sterilization Solutions

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Such as "Cydex" and "Zephrine" when fresh are slightly corrosive. These solutions are not recommended mainly because most professional offices do not use them properly: First, instruments are left immersed far longer than recommended by manufacturers, excessive hours and even days, resulting in corrosion and dulling of sharp edges on knives, scissors, hooks, etc. (a 20 to 30 minute steam sterilization is much less corrosive.) Second, the solutions are not changed as recommended, causing undesirable suspensions, as blood, saline, proteins, medications, detergents, soap, debris, to circulate forward to new instruments. Third, the instruments generally are not rinsed with deionized (softened) distilled water after being removed from these somewhat corrosive solutions. With time and use these solutions become ever more corrosive.

Sontec Instruments 7248 South Tucson WayEnglewood, CO 80112 (303)790-9411(800)821-7496Fax(303)792-2606 A TRADITION OF FINE SURGICAL INSTRUMENTS