Editorial comment for the 2000 update
The problem of buying instrumentsAfter 20 years of editorials on this subject in MIMS Hospital Equipment & Supplies Directory, there is still little published information in this field. The main sources have been publications by various Standards organisations, whose provenance is hard to track down, brochures by a cooperative of individual instrument making companies in Germany, and artides in the Association of Operating Room Nurses Journal, from Denver in the United States. Text-books of peri-operative nursing are even light in this area.
Care of surgical instruments remains a neglected subject, taught only in a few institutions such as the Central Sterilising Supply Department (CSSD) at the Royal Adelaide Hospital in South Australia.
Some changes have occurred because of concerns about cross infection by stubborn heat-resistant viruses - hepatitis, AIDS and CJD, among others. Cardiac catheters designed for once-only use cost $1,000 each, and the pressure to re-use them is understand-able. This practice at a major hospital featured on national television in 1996 and led to hasty additions to the relevant Australian Standard, which then had to be withdrawn hurriedly and rewritten.
Re-use of 'disposable' instruments remains a confused subject. It is usual in most parts of Asia and South America, and many parts of Europe. Simple inspection suggests that provision of suitable irrigating ports and closure by screw-thread lids would make this safe, with a huge saving of money. The commercial pressures, reinforced by in-hospital institutions, are obvious. Perhaps by the next edition of this volume some sense will have been infused into the debate
For now, the following information should be regarded as too detailed for ordinary staff training in the OR or the CSSD. The teacher may use this material as a resource from which the main points can be abstracted and used for overhead transparencies and class notes.
The booklet of 40 pages called 'Proper Maintenance of Instruments' by the Working Group on Instrument Preparation from Germany, 5th edition, 1993, has been available from Drager Australia Pty Ltd, Medical Consumables Division, and they might be approached for single copies for institutions and operating theatre suites. I recommend it strongly.
There are over 30 different brands to choose from in buying surgical instruments in Australia. They vary in quality, price, delivery times, and back-up service. Decisions to buy instruments become difficult in large hospitals because so many different parties are involved - theatre supervisors, purchasing officers, government departments and surgeons - many with different personal preferences who actually use them. Often the purchase is made on the basis of price alone, by someone quite remote from their use.
Standards
It is important to have objective standards for assessing instruments for purchase. For example, the sharpness of scissors can be tested by trying to cut thin gauze or glove rubber with them, and their stiffness can be tested by pressing them onto a simple scale for weighing letters (see below). In a similar way forceps can be checked for their stiffness and grip.
One criticism of such standards is that 200 different surgeons will have 200 different preferences for instrument stiffness, but this is not so. In practice, there will be three opinions - most surgeons will be satisfied with a middle range of stiffness, a few would prefer instruments set 30 - 50% firmer, others will want a setting that is slacker by 20 - 30%, and very few surgeons will want their needs met individually.
Stainless steelThere is no such thing as stainless steel. All so-called stainless steel will corrode through oxidation of the iron under certain conditions. The resistance to corrosion of stainless steel depends on its content of chromium and nickel and a process called 'passivation'. This consists of dipping the finished item in nitric acid, which dissolves dirt and the surface iron atoms, but not the chromium. When exposed to air, these remaining chromium atoms are oxidised to form a very thin but continuous film of chromium oxide, like the surface formed in chromium plating. It is this very thin layer of chromium oxide which prevents the iron atoms underneath from oxidising or rusting. This 'passive' layer thickens with time, and with use, if it is not broken, so that older instruments are relatively more resistant to corrosion.
The passive layer can be broken in various ways:
1. Direct: This may be from scratching by the sharp edges of other instruments, rough handling, piling up of instruments in heavy heaps or by ignorant cleaning with steel wool or abrasives meant for kitchen aluminium.
2. Mechanical strain: Typically this causes a crack into a screw joint when too much force has been applied, for example, when forceps are used to grip something far too thick when a heavier instrument should have been used.
3. Contact with chemical compounds: These include soap or detergent which is too acid or too alkaline, saline solution when contact is pro-longed, some disinfectants, dried blood, serum or other dirt due to poor cleaning after use in operations and other compounds. Such material and dirt are baked on in successive autoclavings. Water supplied for cleaning may be of poor quality, especially its mineral content. This may be from contamination from autoclave pipes which are freshly installed, or contain foreign matter. During operations, blood, secretions, and solutions of saline or iodine should not be allowed to dry on, but be rinsed off regularly. This also stops jointed instruments from sticking and blades from being blunt.
4. Electrolytic corrosion:When dissimilar metals are in contact, a tiny electrical current is set up causing electroplating on one of them and removal of the surface on the other. If a screw or rivet is replaced with a metal different to the rest of the instrument, then corrosion will occur. This also occurs over a long time if instruments made of different metals are in contact repeatedly. Dam-aged instruments may be repassivated by the manufacturer, but this is rarely done. Newer techniques than the nitric acid method described above have been in use for several years.
The corrosion resistance of stainless steel can be tested by immersing it in a solution of copper sulfate and sulfuric acid for several minutes according to the detailed technique described in the relevant United States Federal Standard (see references). A reddish discoloration of the surface appears if the composition of the steel or passivation are at fault. This kind of testing should not need to be done unless there have been repeated problems with corrosion and the supplier has not been helpful.
Stainless steels are of two main types:
a) Those with a higher content of nickel and less carbon. These are much more resistant to corrosion but do not have the same toughness needed for sharp cutting edges. Called 'austenitic', or '300 series', they are used typically for bowls and for tubing.
b) The kinds used for instruments discussed in this article are called `martensitic', or '400 series', and can be given a much sharper and tougher edge, or more durable surface for the jaws of a gripping instrument, but without the same ability to withstand corrosion.
Understanding this resistance to corrosion is important not only for the purchase of instruments but also for their safe cleaning and maintenance, described later. Without adequate cleaning, instruments be-come stiff at their joints, and fracture occurs because of stiffness as well as corrosion. The metallurgy of alloys used for implants, and the selective hardening of instruments for cutting and clamping, is important for similar reasons, and is also discussed in the article in this volume by Vickers, dealing with orthopaedic instruments.
Artery forcepsInstruments to clamp tissue should obviously grip securely without causing unnecessary damage to tissue. They should be consistent in their stiffness and other handling properties if surgeons are to work at their best. Before confirming purchase or accepting instruments after repair or adjustment, features should be checked according to the description that follows here.
Some of this checking should also be part of the inspection of instruments when they are presented for use and cleaned after surgery. Systematic checking of instruments should also be carried out every few weeks or months, depending on how often they are used. Ensuring that these steps are carried out is a responsibility of management. Unfortunately this has become much more difficult in recent years because of industrial problems such as demarcation of duties at work in many cases. In such cases, it is the patient who suffers most, though the work satisfaction of others also suffers through interference with quality.
The features of instruments to check for can be listed in categories and learned readily:
1. General appearance. The surface should be smooth, and edges well finished without burrs;
2. Joints should work easily. It should not take more than 100 g applied to the finger rings to close the instrument. This is tested for in the same way as ratchet stiffness described below and shown in Figure 2. Some people think that the joint should open under the weight of one handle, but this would exclude many good new instruments. Some factory and fresh stiffness is acceptable;
3. The tips of the instrument should not be hooked nor snag. They should meet accurately before the rest of the jaws when inspected against the light and preferably using a magnifier. They should be able to grip an edge of thin paper or the surface of the skin of the palm so that they can then hang without falling. This might seem a painful test, but it is not, as only the very thin dead layer of skin is gripped;
4. The jaw serrations should meet evenly from the tips, and the edges should not put tears into a piece of tissue paper when clamped onto it. The best designs (generally a little dearer) have a smooth gap between the last serration and the joint, to make them easier to rinse and clean during operations; (Figure 1)
Figure 1. Gap between jaws and joint.
5. Ratchet stiffness. For medium weight forceps, such as Spencer Wells and Kelly, it should take a force of 2.5 kg weight to close the first step on the ratchet. This can be checked easily using a kitchen scale. The method is shown in a diagram on the third chart at the end of this article.
The lower finger ring is pressed onto the pan of the scale, while holding the upper one in the fingers. After doing this with 20 or 30 instruments, one gets an accurate 'feel' for the closing force needed, just as a greengrocer learns to judge the weight of a kilo of apples or grapes, or a postal clerk feels the weight of an airmail letter before its weight is checked on a letter scale.
The teeth of the ratchet should not start to engage until just after the tips of the jaws have met. Forceps made by some companies, such as Stille of Sweden, are stiffer than those of other brands. This is because they are made of less springy steel, have handles that have a circular cross section instead of an oval one, and larger teeth on their ratchets. Because their finger rings are a little larger, and have a larger surface area in contact with the operator's skin, the force per unit area remains about the same, and they still feel 'right' for many operators.
6. Unlocking forces. Some forceps are too stiff to unlock easily and safely because of their design, the steel used (and how it has been tempered), and the size and angle of the teeth of the ratchet. Forceps that have become worn through long use may fail to grip tissue securely, especially if the alignment of the ratchet has changed. This can occur because of rough use but can be corrected (see later).This may cause a disaster during surgery, though more often it is just a nuisance.
An acceptable range for the force needed to unlock forceps is 500 g ± 10%. This is also easy to test using a simple kitchen scale. The forceps are held horizontally by one finger ring, and the other finger ring is pressed down onto the pan support for the scale until unlocking occurs. The method is shown in a diagram on the third chart at the end of this article. In this diagram, the forceps have been tilted up almost 45° to show the action more clearly.
A simple test for ratchet security is to drop the closed forceps onto a hard surface (which is slightly resilient, to avoid scratching). If the ratchet is not secure, the handles will jump open. This test is not a good way to treat fine instruments, but is useful for demonstrating the problem with a faulty item.
7. Metal stiffness. Metal hardness can be tested in a laboratory or on a factory workbench for its Rockwell number, a routine engineering measurement. Elasticity or temper can be tested in at least two ways, described in the relevant documents of Standards Associations, for example those of India and the United States. One test is to clamp the joint of the closed forceps in the padded jaws of a vice, and to move the finger rings one centimetre from the original line of the instrument (see Figure 2).
When it is let go, the instrument should resume its normal shape or 'set'. A second test is to clamp the jaws of the forceps onto a wedge of leather or a piece of basswood, 3 mm thick, for 24 hours, engaging only the first step of the ratchet. At the end of that time, the jaws should immediately resume their normal shape when released, and grip evenly and securely from their tips. (See Figure 3.)
Figure 3. Clamping test for metal temper
Failure of metal stiffness can also occur through misuse, when the ordinary elastic limits of the steel of the instrument have been exceeded. If an instrument has been used to clamp thick, tough tissue in an operation, the same instrument may fail when used on more delicate tissue next time because its setting has been changed. If the tissue is deeply placed and contains blood vessels, the result may be problems and complications for the operator. Cheap forceps of poor quality often fail these tests. In ordinary use they stay bent instead of springing back to their original shape after being stressed, and fail to grip tissue. Developing countries a few years ago had a bad reputation for producing instruments that lacked hardness and elasticity from poor quality steel and poor heat treatment during manufacture. Such instruments were then transferred for use in ward dressings, from their, then, low price. Sometimes they were relegated for use by inexperienced doctors in emergency departments, the very circumstance when the best possible help from good equipment was needed.
Dissecting forcepsIf these are too stiff to close properly, they are tiring to the fingers of the surgeon after a few minutes of use, and interfere with the rhythm and accuracy of work. If they are too slack, they close with less than the slight force needed to grip them and keep them from slipping out of the fingers. A useful guideline is that 12 cm forceps should need a force of 300 g weight, applied to the finger groove nearest their tips just to close them. The method of testing is shown in a diagram on the third chart at the end of this article. Toothed orthopaedic forceps with a broader surface for the fingertips to grip onto should have twice this closing force. Dissecting forceps for plastic surgery, such as Adson's, should close at about half this level to avoid diluting the feel of the tissue by the fingers through the forceps. This decreases unnecessary crushing of the skin edge during handling by the operator. These last two recommendations have not been validated by formal studies, but are based on personal observations and observations of some colleagues.
General requirements for dissecting forceps are similar to those for
artery forceps described earlier. Best quality forceps have two rivets
joining the two handles, concealed by the polished finish. Cheaper ones
are spot welded together, like eyebrow tweezers, and are more likely to
corrode; these are often provided for dressing trays and make the lower
level job of removing sutures more difficult and less comfortable for
the patient.
Some dissecting forceps are stamped from a single steel strip and are
cold bent. They are cheaper but stiffer, and will not last as long. The
more junior the doctor or nurse, the better the quality of instrument
they need to achieve the same result as someone more experienced, yet
the cheaper the equipment they are usually given. At the same time they
are more likely to damage instruments, or work in surroundings where instruments
are lost or stolen.
To test the cutting of scissors, take a piece of gauze unfolded to a single thickness and put it on a table. Hold the scissors by one finger ring so that they are in the vertical plane and the other finger ring rests on the table. Put the gauze on the outer two-thirds of the lower blade, and close the scissors. The method is shown in a diagram on the third chart at the end of this article.
The result should be a single clean cut of the gauze. Other test materials are wet tissue paper and thin rubber sheets such as a balloon, dental dam, or a piece of ordinary surgical rubber glove. Rubber is a good test material because it is difficult to cut - any unevenness of the blades will allow the rubber to stretch and avoid being cut. Two to five thicknesses of the gauze may be used to assess the toughness as well as the delicacy of the scissors. The best test material for microsurgical scissors is thin latex rubber from a condom.
Cheap scissors have the blades held together by a rivet instead of a screw joint, and cannot be sharpened any more once the blade edges have been 'touched up' a couple of times. This may be considered a necessary economy for suture scissors used in wards where no instrument maintenance services are avail-able. This is not suitable for dissecting scissors, where the best quality, combined with careful use by the surgeon, give far better value even without facilities for resharpening. This is quite apart from the difference in level of quality of surgical dissection that will be carried out. The mechanism of how scissors actually work is discussed later, in relation to sharpening.
Microsurgical instrumentsThe design and care of microsurgical instruments are dealt with in detail in other articles (Patkin, 1978a, 1978b) and mentioned in general terms in another article in this volume. Some of the more important points will now be mentioned briefly.
The handling of 10/0 sutures, a quarter the thickness of a human hair, and the fine tissues met with in microsurgery, requires instruments that can be handled with special delicacy. The first microsurgical needleholders sold in the late 1960's were made very stiff. In one batch I tested in 1969, it took a force of 1.5 kg applied to the handles to make the jaws close. There is good evidence that accurate suturing re-quires instruments closing with a finger force of 50 - 80 g if normal tremor is not to be aggravated. Micra, an English company making ophthalmic instruments, have advertised their needleholders as being set to close at 65 g. For heavier suturing, such as squint operations, the stiffness should be consider-ably greater.
Microsurgical instruments are best used in a hand-grip similar to that for writing, though a few surgeons hold them in the hollow of the hand like a general surgeon's scalpel used in the usual way. This hand-grip imposes extra design requirements apart from that of stiffness:
" The handle length must be sufficient to reach from the pulps of
the semiflexed fingertips to the cleft between the thumb and index finger;
" The diameter should be about 1 cm at the finger-tips and much less
at the butt, and the cross section should be circular, (each handle is
like a half cylinder). The instrument can be rotated by the fingertips
instead of by coarser movements of the whole forearm (see Figure 4).
Figure 4. Circular cross section for rotatability
These criteria have been translated into practice by a number of designers for the various patterns of needleholders, forceps and scissors now used widely for microsurgery. Additional features of such instruwert designs are concavo-convex jaws which position the needle automatically and also give a more secure grip, handles which are offset to increase the nm l range of rotation, and an easy optional locking ltsrer.The ergonomic basis of design for microsurgical 'instruments is now accepted worldwide.
To house such instruments, it is important to use special protective instrument boxes perforated for autoclaving, and lined by rubber with 1 cm regular projections to hold the instruments in place and stop Item from moving about and damaging each other during transport. Smaller boxes holding just the basic instruments are small enough to be carried in the pocket and given to theatre staff for autoclaving with am need for the instruments inside to be handled. This greatly decreases the possibility of damage to them. Such boxes are now made by several companies, and these should always be bought at the same time its instruments so that a valuable and fragile investment can be protected. Some instruments such as right angled crocodile forceps should also have individual protective sleeves.
Other items to be bought at the same time include lubricants, cleaning solutions and sharpening stones where appropriate, depending on who is going to maintain these instruments. Better instrument makers will also provide instructions for instrument care along the lines discussed below.
Needleholders and needle qualityHow securely a needle is gripped by the jaws of an instrument depends on needle design, alignment, jaw shape and surface and force of grip. The jaws may be selectively hardened by tempering, or have replaceable inserts of tungsten carbide, or a vacuum spray coating of tungsten carbide. Years ago, jaws were sometimes provided with soft copper inserts to give a better needle grip.
The presence of these inserts is now generally indicated by decorative gold plating applied to the finger rings of handles, but the quality of these tungsten carbide inserts varies significantly from one manufacturer to another. With some smaller needleholders, the rough edges of the jaws may fracture and break fine 5/0 nylon suture during knot tying. This has been a special problem with Collier type needle-holders, probably because of the manufacturing habits of one or two far off small factories making just these instruments for larger wholesalers. A force of 2 or 3 kg may be needed for a needle to penetrate tough tissue, though generally it is a quarter of this level in abdominal skin. When a needle is pressed onto a simple kitchen scale with this force, with the first step of the ratchet engaged, it should not twist within the jaws of the needleholder if the surgeon is to avoid problems while suturing. This method of testing is shown in a diagram on the third chart at the end of this article.
As a result of the publication of such data on tissue resistance to needle penetration in the references accompanying this article, at least one major needle manufacturer adopted hard-sell advertising which compared the sharpness of its needles with those of its competitors, using the techniques described. The geometry of needle design and the metallurgy and chemistry of needle manufacture have also entered a new phase.
Stiffness of vascular clamps and other tissue holdersThere is evidence from several studies in experimental animals that if occluding clamps grip major arteries too forcefully, they cause local atheroma, and thrombosis if the level of serum fatty acids is high (de Palma, 1977). The critical level of occlusion appears to be between 1 and 2 kg for bulldog clamps, and this is often exceeded by such clamps which remain in everyday use in many hospitals. To avoid such damage, one alternative that has been tried is the use of occluding intraluminal balloons.
Microvascular clamps can be bought to close at specific levels of force, such as 10 g, 20 g, or 30 g, stiffer ones being more likely to damage the intima and internal elastic lamina of small arteries, and cause thrombosis later (Thurston, 1976), so ruining the chance of success in replantation procedures. Some microsurgeons have avoided clamps altogether, preferring to use limb tourniquets for prolonged periods. Simple calculations can be used to show that only about a 5 g force is needed to occlude arterial flow in a 1 mm vessel, and some ingenious clamp substitutes which look like paper clips have been developed. Clamps have another function: that of stabilising structures as well as occluding them, and the Acland pattern was designed to catch stay sutures for this purpose.
Tissue forceps can cause serious tearing of tissue such as bowel serosa. To avoid this, some models of Babcock forceps are not only set more lightly but have a jaw pattern similar to that of De Bakey vascular forceps. These are made with tungsten carbide by manufacturers such as Snowden Pencer, who pioneered the use of tungsten carbide technology in surgical instruments. If arthroscopic surgery is not being used, the pull on meniscectomy forceps may range as high as 10 kg. As the tissue is to be removed anyway, damage to it only matters if tearing or slip is going to occur. To avoid this, the forceps must have adequately sharp, well spaced teeth and forceful grip. In plastic surgery, it is constantly being re-learned the hard way that fine skin hooks must be used on delicate skin edges instead of grasping forceps, and such lessons slowly percolate to other branches of surgery.
Sutures versus staplesThe increasing role of staples in surgery is dealt with in a separate article. The market for these devices is worth hundreds of millions of dollars worldwide, and predictably there is intense competition and premature marketing of some varieties, with promotion of their use in circumstances which are not always appropriate. There is a learning curve for their use, just as significant here as for other surgical techniques. Haemostatic clips are simpler to consider, but there are striking differences between those who think they are safe and advantageous to use and those who disagree.
Skin clips may appear an extravagance if only the cost of materials is considered. However the saving in time for anaesthesia, staff and theatre use is significant when costed, and only to be counterbalanced against the cost of delayed or failed wound healing if skin edges are not brought together carefully.
RetractorsIt is incredible that wicked handled Deaver retractors are still provided for use in many operating theatres, despite the discomfort and unsteadiness they cause the assistant holding them (Patkin, 1966). The need for better deep exposure has led to the use of long incisions and the development of several different self-retaining retractor systems. Such equipment is now essential for easier and therefore safer operating, deep in the upper abdomen. The Bookwalter retractor system, made in North America, is expensive but superb. No abdominal surgeon should miss the opportunity to try it out. It will be a revelation.
A cheap alternative to the high cost of some of these systems is to use lithotomy posts by the patient's shoulders, with an autoclavable steel crossbar from an orthopaedic table between them. A large sternal retractor is then attached to this bar by several turns of autoclaved orthopaedic traction cord, and tight ened easily. Measurements indicate that traction o 10 and 15 kg is typical in this situation, while the rib soreness that might have been expected practically never occurs.
Analysis of the blade shape of retractors has no attracted much surgical interest apart from the pic tures in instrument catalogues, and an importan chapter in one old surgical textbook (Devine, 1941) An example of a one-off solution is the former use o a duckbill vaginal speculum for mediastinoscopy However, in a general sense, the wide practice of laparoscopic surgery is a way of using very long thir instruments with very long retractors.
General criteria for the handles of instruments and other equipmentThroughout industry and in everyday life, many handles are designed for steel fingered pixies instead o1 normal human hands (Patkin, 1985). Larger retractors, handles for lifting, and knobs to be tightened or loosened should provide an adequate area of con-tact with the hand, with no sharp edges or projections, some angling to avoid ulnar deviation of the wrist, and shaping within the 'power' grip of the hand without having to rely on friction. This also applies to orthopaedic hammers, screwdrivers and chisels, and power tools. Anaesthetists sometimes have a hard time coping with the little connectors and adaptors for endotracheal tubes. By contrast, other instruments need only a fingertip 'precision' grip contact (actually a light pinch grip). Too comfortable a handle can create problems; the thread of a screw can be stripped off, or the feel of pull or pressure on tissue may be too diluted if not through a fine instrument such as a skin hook or thin handled probe. The special requirements for microsurgical instruments have already been referred to, together with references to more detailed information.
Where there is a graduated set of instruments of similar appearance, the size of each should be clearly indicated. This allows for the correct one to be chosen with a quick but reliable glance, sometimes on a less brightly lit area on an instrument table, for example in ear surgery, or choosing the correct item in a sequence of dilators. One way of doing this is by applying one to four strips of 'Surgiband'. Colour coding takes time to learn, especially if staff is changing frequently. There is a standard international col-our code for labelling electronic equipment (such as resistors) with different numerical values, but most people are unlikely to be familiar with it. Engraving which is faint or on a glaring polished surface is not likely to be of much help, nor are markings which wear off with use. General criteria for handle design are easy to list, both for designers and purchasers of equipment which will be held in the hand. A suitable checklist which is easy-to-use contains over 50 separate criteria against which a product design can be compared (Patkin, 1985).
Steps in acquiring instrumentsCaring for instrumentsThe administrative set-up for buying instruments is the same as that described in another article in this volume dealing with the purchase of theatre equipment. Here the emphasis is on the technical details involved.
Much will depend on whether the order is a large one for setting up a department, or a smaller one for replacements of individual new instruments. In the former case, more favourable prices should be negotiated, and surgeons must be involved, especially in the more sophisticated specialities. Often selection is entrusted to a theatre supervisor already acquainted with detailed instrument needs. Some-times, as stated at the beginning of this article, the task is passed onto a lay person who is quite unaware of the implications of choice based merely on price or past reputation.1. Selection
Once the need for a particular instrument has been established, choice of supplier and brand will depend on suitability, availability, delivery time, price, quality control by the supplier, reputation for service, and perhaps government contract.
Prompt backup service, with local technicians for preference, is essential for more complicated equipment if repairs are not to make it unavailable for many months. Maintenance of simpler instruments is a vexed question discussed later. The purchase of instruments and equipment is more than just an exchange of money for items. It should include arrangements for maintenance, accessories such as lubricating, cleaning and testing materials, items such as demagnetisers and sharpeners, protective cases, and information such as service booklets, sales demonstrations, and small seminars or work-shops on equipment care.
2. Delivery times
Adequate stock presents a problem for distributors, as it ties up much capital and storage space, especially for items which are slow moving or likely to become obsolete, and is aggravated by the general problems of importing. Large firms offen have to cope with an inventory of 10,000 to 20,000 separate items. Local companies vary in their ability to deliver the goods and it is useful to know the variation in quality of service provided. With a competitive market which continues to change, it obviously pays the buyer to choose carefully between brands. Some overseas manufacturers are happy to supply orders direct, while others refuse to supply except through retailers who, may also be found abroad.
3. Acquisition
On delivery, instruments should be checked against invoices, and then examined for defects such as abnormal looseness or stiffness, corrosion, and other external damage. If the packaging is damaged on the outside, a check should be made with the insurance agent for the carrier before it is accepted or opened. Cartons which are saved for a time are handy for repacking if early adjustment or servicing is needed, though this takes up much of the storage space, already limited in theatres. Manuals and leaflets for servicing and use should be obtained where they are available, with extra copies for frequent users, protected by lamination, plastic covers, or photocopying onto 'Celcast', a durable substitute for paper.
Once purchase has been confirmed, most items should be marked, usually with an electroetcher, an item which is essential for every hospital today, as is having several persons skilled in its use. The marking should include the name of the hospital, an abbreviation for the department, and month and year of acquisition. Mechanical engraving devices and stamps or dyes are likely to damage instruments, especially when used near a joint, and should not be used.
Metal implants such as hip prostheses must not be marked under any circumstances, as corrosion and rejection of the device may occur following contact with the tissue fluids of the patient. One batch of hip pros-theses had to be discarded in an Australian hospital for just this reason, after advice in an early edition of this directory had been followed too enthusiastically. Items must not be marked if there is a chance that they will be returned or exchanged. Hospital practice should include the use of acquisition books by the department, giving a clear and easy record of what has been bought and serving as an aid to cost control. It is up to the management of a hospital to clarify who should be responsible for selection or rejection of instruments. It is unfair and wasteful to put this responsibility on the shoulders of a lay person who lacks the background to tell which surgical equipment is best, or adequate, from the wide range available.
4. Follow-up
In the complicated setting of a hospital, some purchases turn out to be wrong. Many hospitals have, on fire escapes and in corridors, various devices bought for lifting patients but stored under dustcovers. This is partly because buying equipment is easy but will do nothing to decrease the incidence of back injuries if people are not trained in its use. Most theatres have instruments never likely to be used, as the relic of some surgical enthusiast who worked there for a period.
Some of these errors are a necessary part of the trial and error process in a field with high technical demands and rapid change. However, such errors also reflect lack of analysis before the purchase of equipment and ignorance of the costs involved. There is a lot to be said for labelling all items used in a hospital with their cost of purchase; it would certainly provide surprises and shocks for the staff using them.
For historical and legal reasons electromedical equipment has been looked at much more closely; as well, larger single sums of money are involved in their purchase. However with growing interest, and the continued publication of this Directory, it should be easier for surgeons, theatre supervisors and purchasing officers to get better value for hospital money and better facilities for the basic goal of caring for patients to the best possible degree.
Unlike many other craftspeople, surgeons in a large modern hospital rarely have their own sets of instruments, and common instruments are used and cared for by a large number of people at different times, with the result that what is everybody's business becomes nobody's responsibility. With lack of attention to this area in the past, the quality of instruments in use has suffered, aggravated in this country by the lack of a significant surgical industry and a shortage of technicians competent in the maintenance of instruments.
One of the first requirements in this area is education, starting with lectures to nurses, students, and postgraduates in surgery during their courses, and more detailed instruction to CSSD workers of the type given in courses at the Royal Adelaide Hospital for several years.
Cleaning
Given the basic information on stainless steel at the beginning of this article, it is apparent that cleaning starts with rinsing of instruments during the course of the operation, using a basin with a small brush or cloth, and sterile demineralised distilled water (not saline). This immediately implies more work for the scrub nurse, and raises the question of the benefit of having an extra nurse and more staffing costs compared with the savings and other benefits from instruments which are maintained better.
One can start a stage earlier, with a bias to selecting instruments which are cleaned more easily, such as artery forceps described earlier with jaws less likely to trap clots and debris near the joint, or choosing disposable rather than reusable staple appliers.
Instruments should not be piled in large heaps, to avoid bending or scratching those which are underneath. At the end of the procedure, before dirt (blood, serum etc.) has dried on, they should be washed carefully by aides chosen for their aptitude for instrument care. Studies with radioactive technetium 99 labelled serum protein, which has been allowed to dry on instruments, has confirmed the importance of adequate rinsing before drying occurs.
The people who clean instruments should be able to sit comfortably at an adequate bench with a shallow sink to allow knee room. A chair with adjustable height control should be provided. Lighting should be bright, about 1,000 Ix, and there should be an illuminated magnifier that can be swung into position. Cleaning should be done with fine nylon brushes and toothbrushes, using soft soap with a pH of 8 to 11, with purified mineral free water for rinsing. No abrasives may be used, but there should be a small ultrasonic cleaner within easy reach (see below).
As instruments are handled, those which appear defective should be checked according to criteria mentioned earlier, and unfit ones put into a specially designated container, if they have not already been put to one side by the surgeon or the theatre sister.
Lubrication of joints is now less of a controversial point with manufacturers. Previously, some had advised the use of oils with a high flash point, or a lightly applied silicone spray, neither of which would evaporate during autoclaving. However, the silicone spray especially would form a crust which thickened with repeated applications and was impervious to steam and therefore to sterilisation. It is generally agreed now that it is best to use the newer proprietary cleaning and lubricating solutions, which are advertised and sold by number of the major instrument companies.
Obstinately dirty instruments and the crevices of fin instruments used in microsurgery should be cleaned after each use in a small dental ultrasonic cleaner This advice has been disputed, on the basis that might cause corrosion and blunting of fine points an edges, but such cleaning seems quite safe provide it is carried out for short periods and with simple car against contact with other hard metal and the side of the container.
Ultrasonic cleaners work by creating waves or oscillations at a frequency above 20,000 cycles per second, beyond the normal hearing range. This shake dirt and debris off smooth polished surfaces by process of vacuum bubble formation called cavity tion. To be effective, this needs contact of liquid wit metal without intervening air bubbles, because these are present, they merely get larger and smaller on top of the dirt in time with the oscillation instead of allowing cavitation to take place underneath the dirt.
For similar reasons, the process by which electroplating lifts off instruments is hastened by ultrrasonic oscillation. When an instrument with dirt in recess is held with this part immersed in the ultrasonic bath, there is a little waterborne plume of dirt to be seen streaming away from the instrument which stops after a couple of minutes when the process is complete.
If dissimilar metals are in contact with one another small electric currents develop (as mentioned earlier) resulting in electrolytic corrosion, and this exacerbated under ultrasonic conditions. The rapid mechanical shaking will also blunt metal points an edges as they hit other metal instruments or the metal lining of the container.
Small instruments with awkward crevices should b held by hand and dipped in the ultrasonic cleane (this may be disallowed as a workplace health an safety hazard) or rested carefully in plastic inse trays. In addition, the manufacturer of the ultrason cleaner often provides or recommends special df tergent solutions to wet the metal surface thoroughly as well as supplying other technical advice which should be followed.
One way of cleaning ophthalmic instruments, recommended by Dr G Galbraith of Melbourne, is to soak them in a solution of citric acid, about 100 g/L, followed by an ammonia rinse to clear away the soapy feel of the surface that results, followed in turn by careful rinsing with water because of the damage that if ammonia would do otherwise. Citric acid is used for cleaning stainless steel (austenitic) tanks and tubing in the food industry and in photographic processing equipment, though according to metallurgists it thought to mark and stain stainless steel.
The efficiency of ultrasonic cleaning can be checked by examining instruments under a low power binoci lar microscope, or by special stains for protein debris on which a hospital biochemist can advise. Other standard tests for the effectiveness of ultrason cleaners would be useful, especially for the power generated by their transducers, as this may fail in tf large ultrasonic cleaners now being used for batches of instruments every week or so in some hospitals. Several German instrument firms have developed machines, like dishwashers, specially designed for cleaning instruments in theatres and CSSDs. The: have to be used together with special detergents, b save considerable hand labour and expense if they are looked after properly.
Adjustment and maintenance of instruments
This is best carried out by properly trained instrume technicians, and not by the general engineering section of a hospital. Unfortunately such technicians are scarce. Rather than have their instruments handled by unskilled people elsewhere, theatre supervisors without access to good instrument repairers may wish to designate one person in the theatre, with careful pair of hands, to correct forceps that are too stiff or too slack, by careful bending of the handle and with the warning that the ratchets will be put o of line by an incorrect movement. A method of doing this is shown in a diagram on the fourth chart at the end of this article.
It is best to experiment first on several old pairs of artery forceps to develop the skill to do this well, checking the stiffness with the help of a kitchen scale, as described earlier. Dissecting forceps that are too stiff can be adjusted by bending the two handles first to one side and then to the other. If too slack, the two handles may simply be pulled apart a little, and then realigned by squeezing with a small thickness of wood or metal between the handles near the joint.
In a proper instrument shop, jaws which are out of line can be tapped back into shape on a block of hardwood or on soft metal such as copper or aluminum. A little known but very effective method is to insert one jaw into one of a series of holes drilled into soft metal or hardwood. Manipulating the handle then gives very accurate control of the setting of the instrument. Dissecting forceps whose tips or teeth are not meeting accurately can be cautiously wrenched back into shape, especially if the handles are properly riveted together instead of tack welded. In Australia, there is only a small number of instrument makers who have served their apprenticeship at one of the large European instrument firms, or with Taylor's, the sole Australian firm founded at the start of the century, but which has been out of business for some years. In Germany, instrument makers are forbidden to export their products until they have had five years experience and passed a master craftsman's examination. This is in addition to their three year training apprenticeships with supervised factory experience as well as classroom tuition, and rigorous academic examinations.
The sharpening of scissors and osteotomes needs to be done by experienced technicians using a range of grinding and buffing wheels and compounds, and special sharpening stones, such as the set available from the Richards Manufacturing Company, or from some suppliers of abrasives. The Richards company has also published excellent booklets on sharpening technique and on the care of microsurgical instruments.
The article by Vickers on orthopaedic instruments in this volume has already been referred to and has additional information on sharpening. Much expertise is needed to sharpen scissors. Their blades are gently hollowed in two directions, along their length and across their width. Such blades are ascribed as 'hollow-ground'. The hollowed area extends from the tip to beyond the joint to a raised semicircle called the shoulder, or half-moon, or ride. When the screw joint is correctly tightened and the blades are correctly shaped or 'set', this shoulder has the effect of forcing the two blades together at the point on the edges where they cross and carry out the actual process of cutting.
How scissors cut can be considered in five steps which occur in quick sequence:
" Engagement or contact of the blades with the material;
" Elastic deformation of the tissue;
" Plastic deformation;
" Fracture or tearing;
" Separation.if the blades do not meet at each point along their length as they are closed, material can be stretched and slipped between them instead of being cut, suffering crush damage in the meantime. It was mentioned earlier that elastic material such as rubber dental dam or glove rubber provides a very sensitive test for the efficient functioning of scissors. Sharpening requires two separate actions-flat grind along the bevelled edge, at an angle of 70 or 80°, and hollow grinding on the inner surface of the blade, from the tip to the 'shoulder'. The blades have to be separated for this, which is a task for a professional. During manufacture, the joint is secured by hammering flat or 'peening' the tip of screw, so that it needs careful but forceful removal. Sometimes the screw has to be drilled out, and replaced with a larger one for which the hole must have new thread cut. The shape of angled-on-flat scissors means that it may not be necessary to separate the blades for sharpening, whereas curved-on-flat scissors not only need the blades to be separated, but also the use of special grinding wheels. The cost of such maintenance is high, but usually cheaper than buying a new pair of best quality scissors.
The best value for money is obtained by buying best quality scissors and using them only for cutting tissues, occasionally fine sutures, within their intended limits, and caring for them during cleaning and handling. Most hospital theatre suites can produce a box of expensive instruments no longer in good enough condition to be used, sometimes because of roughness during difficult surgery and often because of rough handling at other times.
Looking to the futureThe selection and care of instruments has been a neglected area in hospitals ever since hospitals took over instrument care, instead of surgeons owning their own sets of instruments. It has become neglected even more as the technology of surgery has expanded and hospital management has become more diffuse.
In less complicated days, Sir Hugh Devine (1941), an outstanding surgeon of his generation, was able to describe the use of his own special design of instruments in the peritoneal cavity in these words:
"After prolonged use of these scissors -always of exactly the same weight - I have been able to develop with them a sense of touch that enables me to recognise, with the tips of the scissors, the slightest difference of tissue density and therefore to identify blood vessels and other structures by the feel of them".
He was probably speaking of a difference in feed-back of touch of less than 50 g of force transmitted to his fingers through the handles of the scissors. This is not all that difficult to perceive through scissors whose blades are not held tightly by the screw joint, if the user thinks consciously of his or her fingers, not being distracted by the stress of other problems at the time of surgery, and practises this mental skill.
Today much of the best operating is done with the fingers and by blunt development of cleavage planes. Unfortunately, the diluted operative workload in some areas of surgery today prevents the continuing accumulation of experience necessary for the maintenance of good technique, just as in music or sport. However, despite the role of intelligent fingers, the need for good instruments should be self-evident. It is just as important to have proper regard for instruments - not clamping heavy tissue, nor thick tubing, with light forceps; not letting the edges of chisels hit metal and not straining fine scissors.
The difficult area of instrument maintenance, with a shortage of properly trained craftspeople, is not likely to improve, but there is some help in the listing of instrument repair facilities in this Directory. Better awareness on the part of surgeons and administrators of needs in this area and the provision of technical advice such as this article are also helpful. It is unfortunate that a national population of 18 million people and a much larger population among our neighhours to the north has not yet been recognised as an opportunity for the development of a vigorous surgical instrument industry here.
No textbook has yet appeared on the care of surgical instruments, but the bibliography in this field continues to grow. To aid in teaching awareness of simple principles of instrument care, this article is followed by a series of charts on the subject which can be used in the teaching of hospital staff.
BibliographyAhlstrohm G. Hospital Instrument Problems - and Some Suggestions for
Relief in American Organization of Operating Room Nurses Journal, 1972.
72. British Standard Institution. Hospital Equipment Guide to British
Standards (current).
British Standards Institution. Standards, titled for various instruments.
Available at offices of the Standards Association of Australia.
Byrd D H. Preventing Spotting of Surgical Instruments. American Organization
of Operating Room Nurses Journal, 1987.
Codman and Shurtleff Inc. Care and Handling of Surgical Instruments, (year
not stated).
Defence Personnel Support Centre. Index of Federal Specifications and
Standards (current). Available from Superintendent of Documents, US Government
Printing Office, Washington DC 20402.
Defence Personnel Support Centre. Current federal specifications for various
surgical instruments.
De Palms R G, et al. Pathogenesis and Prevention of Trauma-Provoked Atheroma.
Surgery 821997; 4: 429-437.
Devine H. Surgery of the Alimentary Tract, Wright, Bristol, 1941.
Du Jovny, et al. SEM Evaluation of Endothelial Dam-age Following Temporary
Middle Cerebral Artery Occlusion in Dogs. Journal of Neurosurgery 1978;
48; 42-48.
Editorial: Standards on Edge. Medical Journal of Australia 1972; 1,621.
Instructions for Ruining Mosquito Forceps. Medical Journal of Australia
1973; 2: 1,136.
Hall E D. Let Ultrasound Clean Your Equipment. Hospital Management 1968;
106: 68-71.
Indian Standards Institution. Indian Standard Specifications (for individual
instruments).
Mansfield PB, et al. The Care of Vascular Endothelium in Paediatric Surgery.
Annals of Surgery 1978; 188, 2: 216-228.
Mueller V. Care and Handling of Microsurgical Instruments. Chicago, 1978.
Newsletter of Biomedical Safety & Standards (monthly). Quest Publishing
Company, 1351 Titan Way, Brea, CA 92621. USA.
Patkin M. The Shape of Retractor Handles. Medical Journal of Australia
1996; 1: 599.
Patkin M. Ergonomic Aspects of Surgical Dexterity. Medical Journal of
Australia 1967; 2: 755-757. Patkin M. Surgical Instruments and Effort,
referring especially to ratchets and needle sharpness. Medical Journal
of Australia 1969; 1: 2,256.
Patkin M. A Haemostatic Clip for Operative Surgical Use. Medical Journal
of Australia 1969; 2: 574-575. Patkin M. Ergonomics of Diathermy Forceps
Design. Medical Journal of Australia 1971; 2: 657-660.
Patkin M. Everything You Ever Wanted To Know About Surgical Instruments
But Were Afraid To Ask. Gown and Gloves 1976; 1, 2-4, 2, 1 (in 4 parts).
Davis & Geck, Australasia.
Patkin M. Ergonomics and the Operating Micro-scope. Advances in Ophthalmology
1978; 37:53-63. Karger, Basel 1978.
Patkin M. Selection and Care of Microsurgical Instruments. Advances in
Ophthalmology 1978; 37: 23-33. Karger, Basel, 1978.
Patkin M. Selection and Care of Surgical Instruments. Clinical Science
for Surgeons, edited Bur-nett, Butterworth, 1981.
Patkin M. Helping Hands at Surgery: a wall chart for operating theatre
training. Davis & Geck, Sydney, 1981.
Patkin M. Ergonomics and Microsurgery. CRC Hand-book of Microsurgery,
Vol. 1, (ed.) Olszewski, 1,325, CRC Press, Boca Raton, Florida.
Patkin M. A Check-List for Handle Design. Proceedings of the 1985 Victorian
Occupational Health and Safety Convention 1985; 307-314.
Technology for Surgery. Monthly Technical Report. ECRI, 5200 Butler Pike,
Plymouth Meeting, PA 19462, USA.
Thurston DB, et al. A Scanning Electron Microscope Study of Microarterial
Damage and Repair. Plastic and Reconstructive Surgery 1976; 57: 197.
Vickers DW. A New Microsurgical Needleholder. Australian and New Zealand
Journal of Surgery 1977; 47; 3: 381-384.
Vickers DW. Design of Microsurgical Instruments. Advances in Ophthalmaology
1978; 37:34-35. Karger, Basel, 1978.
Reviewed by Dr John Cartmill, BSc (Med), MBBS, MMed, FRACS (now Professor of Surgery at Macquarie University0, for MIMS HESD 2000/2001, 12th edition.
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"My" MIMS went to hospitals at no cost —10 or 20 copies to the largest (OR supervisors, purchasing departments), and just one to the smallest.
In 1975,it was only by accident I heard it was to be published. I quickly contacted the publisher, and told him this commercial catalogue had to have to have introductory articles on selection and care of surgical instruments.
Over the next twenty-five years I enviegled a succession of up to 20 colleagues to write editorials in their area of expertise every 2 years. What kind of readership they had is a mystery, but they were used as teaching material for the CSSD course at the Royal Adelaide Hospital, and doubtless elsewhere.
Commercially MIMS was losing money towards the end, and folded in 2002, The publisher, Chris Wills, continues with other successful publications and has generously given permission for copyright to be waived for publication of this material We therefore gratefully acknowledge the role of his companies over the years.
The best source of such information today is "Health Devices" published annually by ECRI. This non-profit organisation employs hundreds of biomedical engineers and other experts, and is recognised by the World Health Organisation and similar organisations around the world as the leader in this field.
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Buying and Caring for Surgical Instruments
Reprinted from MIMS Hospital Equipment & Supplies Directory 2000/01 www.mims.com.au
Michael Patkin, MB BS (Melb), FRCS, FRCS(Ed), FRACS, FESA, CErg. Surgeon, Whyalla Hospital, South Australia. Past President, Ergonomics Society Of Australia. Former Research Associate, Department Of Surgery, Monash University, Melbourne. Honorary Senior Lecturer, School Of Medicine, Flinders University.
Mr Patkin is a general surgeon with interests in the ergonomics of hand function and of surgical instruments for the past 20 years. He has lectured widely in Australia and abroad on these and related topics, and written many papers and chapters for textbooks. He is a member of the editorial board of `Technology for Surgery' published by ECRI, the major international information source for quality standards and testing for surgical equipment, in Philadelphia, USA.
See recent papers by Cartmill and his team on the histology of crushed tissue and its implications for the design of jaws of tissue-holding forceps of various types.
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