Handling and Care of Instruments

Modern surgical instruments are made of stainless steel, an alloy of iron, chromium and carbon. The inclusion of chromium increases the resistance to corrosion. With proper care and attention, surgical instruments will last for years.

In larger veterinary hospitals it may be necessary to have a number of general surgical packs, with additional specialized instruments packed separately. A card index system, outlining the equipment needed for each procedure, facilitates efficient preparation prior to surgery. Coloured tape may be used for identification of instruments from within the same set to allow for easy repackaging; however, this must be used with caution as it provides a useful “hiding place”for bacteria.

Care

• Instruments should only be used for the purpose for which they were designed. Allis tissue forceps should not be used as bone holders and Metzenbaum scissors should not be used for cutting sutures!
• Instruments should always be placed on surfaces, not dropped or thrown.
• Heavy items should not be placed on top of, or adjacent to delicate equipment.
• Instruments with cutting blades should be protected to avoid dulling of the edges.
• Protective sheaths should be left in place until the instrument is ready for use.
• During surgery, the scrubbed nurse (if utilising this role) should ensure that the instruments are kept free of blood and debris by wiping with a sterile moistened swab after each use.

Checks

Instruments should be checked after each procedure.

Other recommended checks:

• Ratchets should close easily and hold firmly.
• Box locks that are too loose will cause misalignment and will not hold tissue securely. When not in use, the box locks should be left secured on the first ratchet.
• The shaft of instruments, in most cases, should be straight to ensure correct alignment.
• Cutting instruments (scissors, osteotomes, chisels, periosteal elevators and rongeurs) should be checked for sharpness and chips in the metal.
• Protective sheaths should be applied for storage.

Needle holders become damaged when too large a needle has been used for the given size and type of needle holders. An appropriately sized needle will be gripped firmly with the jaws locked on the second ratchet. Some needle holders have tungsten carbide inserts, which increase strength and reduce wear on the gripping surface. These instruments are usually more expensive but they will last longer as the inserts can be replaced, therefore prolonging the life of the whole instrument. Instruments with tungsten carbide inserts are identified by their gold-coloured handles.

Titanium alloy is used for microsurgical and ophthalmological instruments. This alloy has a bluish colour that reduces glare under the operating lights. Such instruments are lighter and stronger than surgical steel instruments. Because of the design and physical properties of the instruments, the surgeon is able to control their movements much more easily. Extra care should be taken when handling these instruments because they are not only delicate, but are also expensive to replace. They can be placed in special trays for cleaning and storage.

Manual Cleaning

Before cleaning the surgical pack, the priority is the safe removal and disposal of all sharps! This is important to avoid sharp and needle stick injuries to the theatre nurse when cleaning and handling the instruments. Common sharps to look out for in surgical kits include scalpel blades (there could be more than one used) and various needles (especially swaged onto lengths of suture material).

Always clean instruments straight after use. If thorough cleaning is not possible, then at least rinse the instruments in cold water to remove gross dirt and blood. Hot water should not be used as it causes coagulation of proteins (e.g., blood). Instruments should not be soaked for prolonged periods as this is detrimental to the chromium oxide layer on the instrument surface, which may lead to staining and corrosion. If soaking is necessary, a chemical cleaning solution specifically designed for instruments may be used. Instruments should be cleaned using a detergent specifically designed for instrument cleaning as ordinary soaps and detergents can damage the surface of the instrument. Enzymatic cleaners are available which break down the dirt and grease. Instruments that have movable parts should be disassembled prior to cleaning (e.g., depth gauges and drill guides, etc.) All box locks and ratchets should be opened to ensure thorough cleaning.

Serrations and box locks should be cleaned with a soft bristle brush. Abrasive materials should never be used as they scratch the surface of the instrument, which may collect organic debris in later use and cause corrosion. A final water rinse will remove any traces of detergent prior to autoclaving.

Ultrasonic Cleaning

Ultrasonic cleaners are effective at removing debris from inaccessible areas such as box locks, serrations and deep grooves. These cleaners act by a process of cavitation. Ultrasonic energy produces high-frequency sound waves that generate tiny bubbles in the solution in the cleaner. The bubbles expand until they become unstable and collapse. This collapse generates minute vacuum areas that dislodge and dissolve debris.

The bath is filled to a level one inch above the tray. Only instrument cleaner recommended by the manufacturers should be used. The instruments are placed into a wire mesh tray (heavier, bulkier instruments at the bottom) and lowered into the bath. The tray should only be half full to avoid overloading and damage to the instruments. Instruments are thoroughly rinsed after ultrasonic cleaning to remove any surface debris and detergent residue.

Instrument Lubrication

Following cleaning and rinsing, all instruments with moving parts should be lubricated. Instrument manufacturers recommend the use of water-soluble lubricants such as instrument milk, an oil-in-water emulsion that has antimicrobial properties.

As a general rule, the instruments should be submerged in the lubricant bath for thirty seconds and then left to drain without rinsing or drying. However, if the instruments are to be sterilised in a hot air oven, then all traces of the lubricant should be removed as the intense heat causes the milk to form a “gum,” which is difficult to remove.

Machine or mineral oils are not suitable as lubricants as they leave a sheen on the instrument surface and will inhibit steam penetration during the sterilisation process. Some instruments, such as orthopaedic drills, have their own silicone gel. This should always be used in accordance with manufacturer instructions.

Once the cleaning process has taken place, surgical instruments must be left to dry. Instruments must be laid out flat with any ratchets and hinges open to ensure adequate drying and reduce the risk of rust damage. Instruments are always air dried in a clean, low-traffic area to avoid contamination. Alternatively, a drying cabinet may be used. Use of a cloth or towel to dry surgical instruments will lead to accumulation of debris, which could harbour bacteria.

Sterilisation

Surgical instruments and equipment are sterilised before each and every subsequent use. The sterilisation process takes place after the instruments have been cleaned and are dry.

Heat Sterilisation

Autoclaves

This is the most widely used and efficient method of sterilisation and is also the most economical. Most items used within the veterinary practice can be autoclaved and include:

• Instruments
• Cloth drapes and gowns
• Swabs
• Most rubber articles – need to check with manufacturer/instructions
• Some plastic goods – need to check with manufacturer/instructions

References

1.  The Animal Industries Resource Centre Course materials – Certificate IV in Veterinary Nursing.