| Problems in Maintenance of Stainless Steel Surgical Instruments |
Corrosion of Stainless Steel Surgical Instruments is a common problem both to the Surgeon and the Instrument Maker. The blame is likely to fall on the Instrument Maker. There is a need for an explanation in regard to the grade of Stainless Steel used to make Surgical Instruments. Also a question that always arises is as to why Stainless Steel should rust under any circumstance. We wish to explain below the causes, which make rust or corrosion occur on any Surgical Instrument.
- A wide range of Metallurgical properties are constituted in one single classification of the metal called Stainless Steel. It has Iron & Chromium, but also may have Carbon, Nickel, Sulfur, Tungsten, Manganese and many other elements. But it is Chromium, which imparts the Stainless Steel quality. Hence the more Chromium is present in the Alloy the more resistant it is to corrosion. Carbon reduces this effect of Chromium. But it is necessary to harden the Instrument. Hardness is a primary requirement in Instruments, which have sharp edges, and for all kinds, which have to perform the application for which, they are meant for. For example, to cut, to hold, to open, to close etc. It is an unhappy circumstance that there are only a few Stainless Steel Alloys, which can be hardened sufficiently to manufacture any type of Surgical Instrument. These Alloys are high in Carbon content. They belong to the broad class known as Stainless Steel and are the least corrosion resistant in the group of metals. This problem is not evident on Stainless Steel Surgical Implants as they do not require hardening and are made of Alloys with zero Carbon content.
- The next type of corrosion, which is commonly
seen on the Surgical Instruments, is that which
takes place on the blades of knives, in box
locks, between blades of scissors etc. In these
cases the Instruments may become useless. The
main causes for these kinds of corrosion are
as follows:
- Inadequate cleaning & drying immediately after use
Any foreign material either organic or inorganic on the surface of any hardened Surgical Instrument is likely to promote corrosion. Instruments, which have been exposed to Blood, Tissue, Saline & Other Foreign matter have to be rinsed in, warm water before they are dried. Instruments can corrode if they are stored with trapped moisture. We recommend Ultrasonic cleaning to clean Instruments.
- Autoclaving
Corrosion can take place if the autoclave is not functioning properly. Autoclaves in which, large amount of corrosion takes place have to be checked immediately for leaking valves. Such Autoclaves may not be drying the Instruments adequately or may be drawing corrosive matter back from the drain. Cloth used to wrap Instruments to be autoclaved may contain residual detergents, bleaches or starch. These can promote corrosion at the operating temperature of the autoclave.
- Water
Corrosion can take place if tap water is used instead of distilled water to generate steam. Because tap water contains minerals which may cause discoloration and staining on the surface of the Instruments. When corrosion does occur in Surgical Instruments, it is usually of a superficial nature. This could be avoided by carefully adhering to the manufacturers guidance on maintenance of Surgical Instruments. In some cases the corrosion can be removed by repolishing the Instrument by the manufacturer.
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| General Instructions on Care and Maintenance of Surgical Instruments |
Instruments used in surgery are the products
of a few highly skilled craftsmen. At their
best, they not only reflect craftsmanship but
a high degree of artistic ability in design.
When such Instruments are given the very special
care, which they deserve, they will retain their
workmanship and function well for long.
- Treatment of brand new Instruments
Brand new instruments must be cleaned before
the first sterilization or use. Protective caps
and protective films must be removed completely,
for example in the case of chisels, raspatories
or microsurgical instruments.
- After Use
- For machine cleaning, place instrument
in a wire basket suitable for the cleaning
process (make sure cleaning solution and
rinse water from machine comes into contact
with all parts of instrument).
- Completely dismantle any dismantable instruments.
- Preferably dry disposal. For wet disposal,
use an active cleaning disinfectant. Rinse
the instrument thoroughly with clear, flowing
water before machine cleaning and disinfection.
- If necessary, treat with ultrasound according
to the manufacture's instructions:
- For effective mechanical support
during manual cleaning.
- For pre-treatment of instruments with
dried-on grime before machine cleaning.
- Microsurgical instruments and instruments
with fine working ends should not be
treated with ultrasound. They should
be cleaned either manually or in the
washing machine. In case of cleaning
in a machine please use a suitable storage
rack.
- Clean manually or in a machine. Follow
manufacturer's instructions.
- Manual Cleaning / Disinfection
- Place instrument into a suitable disinfectant
with active cleaning properties so that
all surfaces, inner cavities, lumens and
openings come into contact with the solution.
- Follow the disinfectant manufacturer's
instructions. After chemical disinfection,
always rinse thoroughly with clear, flowing
water. Follow the instructions provided
by the manufacturer of disinfectant.
- Remove any dirt still clinging to the
instrument with a soft synthetic brush.
Do not use a scouring or metal brush.
- Clean any lumens and conduits with soft,
round, synthetic brushes. Please note, the
lumen and the brush must have the same diameter.
- Final rinsing to be done with distilled
or deionized water.
- Dry instrument with an absorbent, soft
and lint-free cloth.
- Dry lumens and conduits with compressed
air.
- Care / Testing / Storage
- Let instrument cool down to room temperature.
Lubricate movable parts (e.g. joints and
ends) slightly with special sterilization-capable,
vapour-permeable lubricant.
- After each cleaning, disinfection process,
check the instrument to make sure it is
clean, it functions properly and it has
not suffered any damage, e.g. bent, broken,
fractured or worn parts.
- Discard any damaged and defective instruments
and replace.
- Storage
- Place instruments with the fine working
end and/or microsurgery instruments in a
suitable storage racks.
- Secure instruments with lock in the first
detent.
- Machine Cleaning / Disinfection
- Select the program according to the material
(e.g. stainless instrument steel, aluminium)
of the instrument to be cleaned. Follow
the machine manufacturer's instructions.
- Final rinsing to be done with deionized
water.
- Leave sufficient time for drying.
- Remove the instrument from the machine
immediately after the program is do.
- Sterilization
Steam sterilization must be carried out according
to a validated stream sterilization process
(e.g. with a sterilizer meeting the specifications
of EN 285 and validated according to EN 554).
When using the fractional vacuum method, use
the 134°C/2-bar program for sterilization with
a minimum hold time of 5 minutes.
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