Surgical Instrument Care

Cleaning & Sterilising

Washing instruments rapidly after surgery prevents blood from drying and is the best defence against corrosion, pitting and staining. Even if sterilisation will take place later, the washing process should begin immediately post-surgery. If more time is required, keep instruments moist under a wet towel, or use a trigger pack filled with water to spray them down quickly. When cleaning, use only solutions that specifically state on the label ‘for surgical instruments’.

Sterilization
Obviously, all surgical instruments are sterilised prior to surgery to prevent infection, however sterilization can still leave contaminants behind if not properly undertaken. Sterilise all instruments that open and close in the open position, to allow better steam penetration. Pans or trays with perforations also enable better steam penetration and aids in more effective drying, too. Place heavy instruments at the bottom and more delicate instruments on top. If sterilising in pouches, do not stack them during sterilisation. When possible, pouches should be sterilized on their side, leaning against another pouch or steriliser chamber wall.

Ultrasonic Cleaning
Ultrasound is energy in the form of a wave motion which is above the maximum level of audible sound. This energy is transmitted to the cleaning solution via a bank of transducers underneath the machine. The result of this process is termed cavitations, tiny bubbles of vaporized liquid which explode when they reach a high pressure. Cleaning takes place as shock waves dislodge soil from the surface of the contaminated articles placed in the water bath.

Ultrasonic cleaning is one of the most efficient and effective cleaning methods available. The process should take 3-5 minutes. Extended times aren’t recommended as it’s likely to re-deposit the soil removed back onto the instruments.

Generally, it is difficult to establish guidelines for cleaning time due to several factors that need to be considered, such as the variety of instrument sizes and weights, the type of cleaning solution and the machine’s capacity. It is therefore wiser to start with a few parts so that they can be cleaned quickly and thoroughly. You can add additional parts and check to ensure the same cleaning results.

Use distilled water or tap water with a pH neutral ultrasonic solution to properly fill the tank of your ultrasonic cleaner. Never use a manual soap in the ultrasonic cleaner and always follow proper dilution instructions. A neutral pH ultrasonic cleaning solution, when properly mixed, effectively reduces the surface tension of the solution and increases the ultrasonic cavitation process. The solution should be changed at least daily or sooner if the solution appears dirty or murky.

After filling the tank with water (not temperature critical) and adding a measured amount of recommended detergent, switch on your machine for a few minutes in order to expel dissolved air bubbles as these bubbles will affect the cleaning effectiveness. You will notice a change in sound and hear a high pitched hissing sound when the degassing process is completed. When loading each time, place the basket/tray inside the tank gently to avoid re-introducing air into the fluid. Degassing time will vary depending on type of chemical used (e.g. aqueous or solvent), temperature, viscosity etc.

During the de-gassing process, clean instruments of all visible debris by hand-washing them in a pH neutral soap. When placing instruments in the unit, open them so they are fully exposed to the cleaning process. Ensure instruments have plenty of room by not over loading the unit, and don’t mix dissimilar metals (such as aluminium and stainless steel) in the same cycle to prevent cross-plating.

Dropping heavy, sharp or hard parts into the tank can damage your ultrasonic cleaner. You should use a basket or tray in order to prevent damage to the transducers and also to protect the tank from scratching. Do not use baskets, trays or racks fabricated from heavy and dense material or soft materials such as rubber, wood and fabric as they will absorb ultrasonic energy and make cleaning less effective.

Upon completion of the cycle, remove instruments immediately and rinse them. Dry your instruments thoroughly with a towel, ensuring that no moisture is left on them.

Testing an Ultrasonic Machine
To test your machine’s function, fill with the usual solution, turn the machine on and view the surface of the water. If you see sonic ripples in the water, your machine is working. If the surface of the water is totally flat, your machine may have a transducer problem.

You can also test your machine using a piece of standard household aluminium foil measuring approx. 1 inch greater than the depth of the tank by the width (long dimension) of the tank.

Turn the machine on for few minutes to degas, then place the foil into the tank. The foil long dimension should be positioned with the long tank dimension. The foil should extend downward, but should not touch the tank bottom.

Hold the foil as steady as possible in the centre of the tank and turn the machine on for 10-15 seconds. Turn the cleaner off and remove the foil. Shake the foil dry of any water droplets, and inspect it closely. The foil surfaces should be uniformly perforated & evenly covered with tiny pebbling effect over the entire surface

Australian Standard AS 2773-1999: Ultrasonic Cleaners For Health Care Facilities

Steam Autoclave
A steam autoclave is the most common method for sterilizing instruments. Following are a few points that will help you get the best results:

• When using an autoclave, only use distilled water to fill the reservoir. Tap water contains minerals which can stain your instruments and create a scale build-up in the autoclave.
• If your autoclave has a steam line filter, clean it regularly using the manufacturer’s recommendations as a minimum guide.
• Before autoclaving, lubricate all instruments that have moving parts. Use a surgical lubricant rather than industrial oils.
• Completely drain and cool the unit and clean the inside chamber walls once a week with a specific autoclave cleaner. This will help prevent build-up of scale and will allow the steriliser to operate more efficiently. Don’t be afraid to scrub vigorously.

Cold Steriliszation
Cold sterilisation of instruments is not a recommended method of disinfecting surgical instruments. Immersing instruments for long periods of time in any solution can prove damaging, in fact, this should never happen for longer than 20 minutes. Avoid immersing instruments with tungsten carbide inserts (such as needle holders with gold handles) in solutions containing Benzyl Ammonium Chloride (BAC) because it can loosen the tungsten carbide.

Lubrication
A simple and effective way to keep instruments in excellent condition is to lubricate them after every cleaning. All moving parts on instruments, such as joints, box locks, ratchets, and screw joints, should be lubricated regularly. This will keep them from rubbing and scraping, and it prevents dulling and strain to joints and hinges. Before autoclaving, lubricate all instruments that have moving parts. Use a water-based surgical lubricant, because it’s steam penetrable.

Don’t immerse instruments in a lubricant bath, because it may contain bacteria from previous instruments that were also dipped into this bath. A lubricant spray is a cheaper and more convenient alternative.

Low-quality Instruments
When it comes to surgical instruments, lower price always equals lower quality and durability. These instruments can be processed and sterilised alongside high-quality instruments, however they will rust quicker and this rust can damage your high-quality instruments during sterilisation. If cheaper instruments begin to break down or rust, remove them from the surgery pack and dispose of them immediately.