News / July 2, 2020
The cleaning of surgical instruments is defined as the process of removing foreign material (e.g., bioburden, biofilm) from the instruments and is usually accomplished using water with detergents or enzymatic products that are suitable for use. Surgical instruments must be thoroughly cleaned before high-level disinfection and sterilization because inorganic and organic materials that remain on the surfaces of instruments interfere with the effectiveness of these processes. As you’ve been told many times, “If it’s not clean, it can’t be safe!”
The proper cleaning of surgical instruments starts in the O.R. by placing the contaminated instruments into sterile water or an approved enzymatic detergent. Alternatively, the instruments may be sprayed with enzymatic instrument foam to keep the instruments moist and to start the cleaning process.
This first step in the cleaning process at the point of use in the O.R. is vital because if soiled organic materials dry or bake onto the instruments, the removal process becomes much more difficult. Even worse, it can render the disinfection or sterilization process less effective, or even ineffective. This is why it is so important that surgical instruments be presoaked or rinsed in neutral pH (7 or lower) water immediately after use and prior to transport to prevent blood from drying and to soften or remove blood from the instruments.
Manual cleaning is required in those areas that do not have mechanical cleaning units (e.g., ultrasonic cleaners or washer disinfectors). Manual cleaning is also required for fragile or difficult-to-clean instruments (e.g., Kerrison Rongeurs, laparoscopic instruments, etc.).
There are two essential components of manual cleaning, friction and fluidics. Friction (e.g., rubbing/scrubbing the soiled area with a brush) is a time-honored and dependable method. Fluidics (i.e., fluids under pressure) is used to remove soil and debris from internal channels, sharp internal corners and dead-spaces. This step is necessary when the instrument’s design does not allow a brush access through a channel or contact with an internal surface(s).1
The use of a washer-disinfector requires additional care when loading surgical instruments into the unit. Specifically, hinged instruments must be fully opened to allow thorough and complete contact with the detergent solution. Instruments should not be stacked in washers to ensure proper contact with the detergent solution on all of the surfaces. Finally, all modular/take-apart instruments should be disassembled as per the manufacturer’s IFUs.
The most common types of mechanical or automatic cleaners are ultrasonic cleaners, washer decontaminators, washer-disinfectors, and washer-sterilizers. Ultrasonic cleaners remove bioburden and biofilm by cavitation and implosion. They do this by pulsating the cleaning solution 12,000 to over 16,000 times per second which generates powerful waves of acoustic energy. These acoustic waves of fluid energy break the bonds that hold the bioburden and biofilm to the surfaces of the instruments.
The use of ultrasonic cleaners is not without risk. Bacterial contamination can be present in used ultrasonic cleaning solutions (and other used detergent solutions as well) because these solutions generally do not make antibacterial label claims.2 Even though ultrasound alone does not significantly inactivate bacteria, sonication can act synergistically to increase the cidal efficacy of a disinfectant.3 Users of ultrasonic cleaners should be aware that the cleaning fluid could result in endotoxin contamination of surgical instruments, which has been known to cause severe inflammatory reactions.4
Washer-sterilizers are basically steam sterilizers that have been modified to both wash and steam sterilize instruments. These units clean by filling the chamber with detergent and then forcing steam through the chamber to provide the necessary cleaning agitation. The instruments in the chamber are then rinsed and subjected to a short steam sterilization cycle.
Another popular style of washer-sterilizer employs rotating spray arms for the wash cycle that is then followed by a steam sterilization cycle at 285°F.5 6 Washer-decontaminators/disinfectors function much like a standard dishwasher that uses a combination of water pressure/circulation and detergents to remove bioburden. These units sometimes have a cycle that subjects the instruments to a heat process (e.g., 93ºC for 10 minutes).7
1 Reichert M., Preparation of supplies for terminal sterilization. In: Reichert M, Young JH, eds. Sterilization technology for the health care facility. Gaithersburg, MD: Aspen Publication, 1997:36-50
2 Miller CH, Riggen SD, Sheldrake MA, Neeb JM. Presence of microorganisms in used ultrasonic cleaning solutions. Am. J. Dent. 1993; 6:27-31
3 Jatzwauk L, Schone H, Pietsch H. How to improve instrument disinfection by ultrasound. J. Hosp. Infect. 2001; 48 (Supple):S80-S83
4 Richburg FA, Reidy JJ, Apple DJ, Olson RJ. Sterile hypopyon secondary to ultrasonic cleaning solution. J. Cataract Refract. Surg. 1986; b12:248-51
5 Schultz JK. Decontamination alternative. Infect. Control Hosp. Epidemiol. 1990; 11: 8-9
6 Rutala WA, Shafer KM. General information on cleaning, disinfection, and sterilization. In: Pfeiffer JA, ed. APIC infection control and applied epidemiology: principles and practice,. St. Louis: Mosby, 1996:15.1-15.17
7 Leonard DL, Mills SE. Comparison of automated instrument cleaning: preliminary results. Infect. Control Steril. Technol. 1997:20-23, 26-28
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