The uncertainty that surrounds the exact causes and incidence rates of surgical site infections in the outpatient setting extends to the role that sterile processing plays in their prevention - or the role that a lack of proper processing plays in their spread.

One recent incident shows the sterile process's vital importance to quality care. When two infants died and five others became seriously ill at Los Angeles's White Memorial Medical Center late last year, an outbreak that temporarily shut down the facility's neonatal and pediatric intensive care units and put staff on high alert, the cause was traced to an improperly cleaned and disinfected laryngoscope carrying the bacterium pseudomonas.1

"There has not been, to date, a comprehensive study relating SSIs to sterile processing," says Steve Johnson, manager of sterile processing at Tacoma General and Mary Bridge Hospitals in Tacoma, Wash. "But we know much about the role of sterile processing activities in the prevention of infection in general. Because pathogenic organisms and their spores can remain intact on the surfaces of medical devices if they're not properly cleaned, disinfected and sterilized, these devices can easily contaminate the wounds of surgical patients by coming into direct contact with them during procedures."

As a result, it's clear that sterile processing is a fundamental step in preventing the incidence of SSIs at any surgical facility. Here's a rundown of the basics.

Providing the proof
To see the importance of sterile processing, says Mr. Johnson, "one only has to look at infection rates following procedures performed where thorough cleaning and terminal sterilization are not carried out. When there is a lapse in procedure or protocol in sterile processing, it is sometimes manifested in an outbreak of infections or complications suffered by affected patients."

"If equipment isn't sterile - if it isn't thoroughly cleaned and the bio-burden isn't completely removed - and it's a sterile procedure, you can easily transmit infections to patients," says Susan Klacik, BS, CRCST, ACE, FCS, corporate director of sterile processing for Forum Health in Youngstown, Ohio. "Infection control standards are fairly stringent, and they start in the decontamination room."

For a study published in the October 2006 issue of the Journal of Clinical Microbiology, researchers from the University of Southampton in Southampton, United Kingdom, microscopically examined instrument sets obtained from the sterile processing departments of nine National Health Service primary care facilities to demonstrate how the ineffective cleaning of surgical instruments could be a vector for the transmission of hospital-acquired infections.2 While none of the 260 instruments examined showed microbial colonization, many were heavily soiled with protein deposits and some exhibited potentially hazardous crystalline deposits. The researchers concluded that, in order to prevent outbreaks of nosocomial infections, the standard for instrument decontamination must be raised and enforced.

Further, a study published in the October 2005 issue of the journal Healthcare Epidemiology by researchers at the University of Pennsylvania and the Veterans Administration Medical Center in Philadelphia determined, through its stated aims of identifying the usefulness of a healthcare failure mode and effects analysis of biological indicator monitoring in targeting errors in complex systems, that no patients suffered transmitted infections when surgical instruments were properly sterilized.3

Your processing options
The work of central sterile consists of two main procedures: disinfection and sterilization. Disinfection is the destruction of harmful, but not necessarily all, microorganisms on an instrument or piece of equipment. Different levels of disinfection - low, intermediate and high - are effected through different disinfectant products designed (and approved by the U.S. Environmental Protection Agency) to kill microbes with different levels of resistance under prescribed concentrations, contact times and temperatures.

Sterilization, on the other hand, is the destruction of all forms of microbial life on equipment and instruments through specialized procedures. Several methods of sterilization exist. Infection control experts regard steam sterilization as the most effective method for items that can withstand the high temperatures and pressures involved. It is also the method most commonly employed among surgical facilities.

One variation of the steam method, flash sterilization, bypasses the standard wrap- or container-based processing for a more rapid cycle, though it is viewed with some controversy. The Association of periOperative Nurses and the Association for the Advancement of Medical Instrumentation, along with other infection control experts, advise against flash sterilization, arguing that facilities under time and financial pressures may opt for the speedier procedure at the risk of eventually lapsing into substandard practices that compromise patient care. Many facilities do rely on flash sterilization in a pinch, however, and the Joint Commission has noted that it hasn't collected enough evidence of flash's risks to develop stricter standards on its use.

If the items are immersible, liquid sterilization is an option, although the products used present a continuing expense and items to be sterilized can't be packaged before sterilization, as they can in steam sterilizers. Gas sterilization methods such as ethylene oxide (also known as EtO) use low temperatures, but can take as long as eight hours to complete a single cycle and require the exhaust of the fumes that are a by-product of the process. Plasma sterilization is faster, but doesn't have a high rate of penetration.

Whether the decontamination process is completed by disinfection or sterilization is a question that is ultimately decided by how likely it is that the instrument, if contaminated, would cause an infection. According to the Spaulding Classification System of critical, semi-critical and non-critical devices, items that enter sterile tissue and come in contact with the vascular system (such as implants) must be sterilized. Items that come in contact with mucous membranes or non-intact skin (such as anesthesia equipment) should be sterilized or at least high-level disinfected. Items that come in contact with intact skin but not mucous membranes (such as blood pressure cuffs) can be low-level disinfected.

Down to details
"Reducing and/or eliminating SSIs is a complex endeavor involving many risk factors," says Mr. Johnson. "But reducing the infection risk from contaminated instruments and equipment should be fairly straightforward if an organization has strong policies and procedures based on the scientific, evidence-backed recommendations such as those established by the CDC, the AAMI, APIC and AORN."

Certain steps are worth emphasizing, though. "If it can be disassembled before sterilization, it should be," says Ms. Klacik. "That will allow all surfaces exposure to the steam."

Interior surfaces, especially those of cannulated instruments, present what is perhaps sterile processing's biggest challenge, and one that's faced on a routine basis. "If we think of the 'nooks and crannies' where a single cell or spore might escape cleaning, sterilization and disinfection, it underscores the importance of thorough cleaning to physically remove as much of the bio-burden as possible to increase the efficacy of the sterilization process," says Mr. Johnson.

Such thorough cleaning should take place as soon as possible after an item's use, experts assert, as dried debris is particularly difficult to remove from instrument interiors. And this cleaning should be undertaken even when an item is removed from its original wrapper for its first use.

"A lot of people aren't aware that even brand new items need to be decontaminated and then sterilized," says Ms. Klacik. "It's not uncommon for them to still have manufacturing oils on them, and steam can't penetrate the oils to reach the surface."

Ms. Klacik admits that having your own facility's dedicated central sterile personnel conduct the cleaning of instruments and equipment arriving at your facility trumps the guarantees of manufacturers or any other handlers.

"Some doctors, like ophthalmologists, like to bring their own instruments to your facility," she says. "We always make sure to wash them first before sterilizing them for the case. Honestly, you don't know how the previous facility they were used at washed them, how they were stored or transported. I just don't trust anybody else to clean instruments to be used in my facilities."

Above all, she says, thorough disinfection and sterilization of surgical devices depends on a thorough reading of the device manufacturers' written directions. "Not just the sales rep telling you to process it like you normally do, but the manufacturers' recommendations in writing," she says, in the event that an extended sterilization cycle or other special condition are required. "You do have to ask sometimes for them, but they do have to provide them to you."

Tracking and training
The concerns of sterile processing don't end with the end of the sterilizer's cycle. Some manner of backup is required in the event that an infection incident does occur.

"There have been incidents of infection clusters traced back to a piece of equipment," describes Mr. Johnson. "This has been well documented in previous literature as it relates to flexible scopes. That's why it is crucial to record serial numbers of scopes during the processing phase, so they can be directly linked to the patient or patients they were used on.

"Also, when investigating an outbreak of SSIs," he continues. "It may be a part of the root cause analysis to examine common surgical instruments for evidence of remaining bio-burden or infectious organisms by culturing and DNA comparison to cultures obtained from patients presenting with post-op infections."

In the case of the White Memorial Medical Center outbreak, the infants' deaths and illnesses led to a review of protocol and a re-emphasis on the post-processing labeling of instruments.

Conventional wisdom holds that the best defense is a good offense, and it goes without saying that, in the healthcare arena, a good offense begins with education.

"A thorough sterile processing effort should ensure that staff have adequate and comprehensive training and be given access to the latest information, technology and products," says Mr. Johnson, noting that the field doesn't stand still. "Best practices and improvements in products and equipment continue to emerge which afford the highest degrees of sterility assurance."

Ms. Klacik notes that the burden of knowledge that a sterile processing department's staff has to bear - mastering how to disassemble, clean and reassemble every reusable device for every specialty performed at the facility - makes regular education essential.

"I try to educate as much as I can through periodic in-services, with the help of the sales reps," she says, "because there is always something new out there, a new product or situation."

In addition to keeping your staff up to date, don't neglect the potential need to upgrade the sterile processing department itself, says Mr. Johnson. The oversight, monitoring, preventative maintenance and frequent inspection of all processing equipment and its environment - from the floor to the ceiling - is key to continued quality, as is the routine review and revision of processing policies and practices.

Return on investment
"Sterile processing must be presented as a front line of defense in the prevention and fight against surgical site infection," says Mr. Johnson. "Proper cleaning of equipment and instruments in the surgical center should be a core competency and stressed along with hand washing and other measures designed to limit the risk of infection. The return on investment for surgical administrators is an assurance that active steps are being taken in the protection of patients."

References
1. Cook D. "Infant Deaths May Be Linked to Dirty Laryngoscopes." Outpatient Surgery E-Weekly. 25 Dec. 2006.