Cleaning, disinfecting and sterilising are the three levels of instrument care.
Cleaning removes dirt, debris and biological material from surgical instruments. You can clean surgical instruments manually or mechanically using water and detergents or an enzymatic cleaner. Thoroughly clean your instruments, because debris that remains on instruments can interfere with further disinfection/sterilisation or corrupt research data. Cleaning is the first step toward sterilisation and sometimes is all that is required.
Disinfection can be broken down into three tiers: low level disinfection (LLD), intermediate level disinfection (ILD) and high level disinfection (HLD). LLD eliminates all vegetative bacteria (except tubercle bacilli), lipid viruses, some non-lipid viruses and some fungi in less than 10 minutes. ILD destroys tubercle bacilli, mycobacteria, lipid enveloped and some non-lipid enveloped viruses and fungus spores. In addition to killing these microorganisms, HLD can also kill bacterial spores, though not in a high number. The CDC recommends a 90 minute soak at 25°C.
Sterilisation destroys all microbial life. Some chemical sterilants can be used as HLD disinfectants when used for shorter exposure periods. Dry heat or autoclaving are the preferred method of sterilising surgical instruments.
The first step in properly cleaning your surgical instruments is to rinse off all blood, bodily fluids and tissue immediately after use. Dried soils may damage the instrument surface and make cleaning more difficult. Rinse your instruments in cool water. Hot water can cause proteinous substances to coagulate. If desired, soak your surgical instruments in cool water with an enzymatic detergent. The detergent helps to dissolve the proteins and break down oils. Then, the instruments may be cleaned manually or mechanically in a washer or ultrasonic bath.
If a mechanical cleaning method is unavailable, manual cleaning may be necessary. Likewise, if instruments are easily damaged, complex (requiring disassembly) or have small lumens, they may need to be cleaned manually.
When cleaning your instruments manually, wear heavy-duty rubber gloves, a plastic apron, eye protection and a mask. Use only neutral pH detergents. If your instruments are not rinsed properly, low pH detergents may break down the protective surface of stainless steel instruments and cause black staining. Likewise, alkaline detergents may leave surface deposits that cause a brown stain and interfere with the smooth operation of the instrument.
Use soft plastic cleaning brushes to scrub the instruments. Do not use steel wool, wire brushes or other abrasive materials that could scratch the finish or dull your instruments. Hold the instruments below the surface of the water when you scrub them to avoid splattering contaminants. Be sure to brush out all crevices, teeth and grooves. Rinse each instrument thoroughly under running water. Open and close hinged instruments like scissors, hemostats and needle holders under running water to thoroughly rinse detergent from the hinges.
Visually inspect your instruments to ensure they are free of stains and tissue. Check each instrument for proper function and condition. Scissors blades should be tight and should open and close smoothly. Forceps and tweezer tips should be properly aligned. Like the scissors, the hemostats should not be loose. Verify that they lock and unlock easily. Close the needle holders and hold them up to the light. Light coming through the tip indicates that the jaws are worn. Knives and cutting blades should be sharp and free of nicks and chips. After a visual inspection, dry the instruments with a soft cloth. This minimizes the risk of corrosion and the formation of water spots. Use a spray lubricant in the hinges to improve the function of the instrument.