Preventing Surgical Site Infections in ASCs

By Kathy Dix

Ambulatory surgery centers (ASCs) have long been known for their low infection rates related to surgical site infections (SSIs). There are several theories about why the rates stand in such marked contrast to SSI rates in hospitals. One theory suggests that patients are in a healthier environment to begin with — no sick patients coughing in the corridors — and are thus less likely to be exposed to pathogens. Another theory suggests that because the surgery is typically shorter, there is less time for the wound to be exposed compared to a traditional, inpatient procedure. And a third theory suggests that the patients themselves are healthier, and are thus less likely to be susceptible to pathogens to which they are exposed.

Any of these hypotheses is reasonable. The real question is, how does an ASC maintain low infection rates, and continue to improve said rates until they are as close as possible to zero?

Getting the Patient Involved

Enlisting the patient’s help is one means of reducing the incidence of SSIs, says Vicki Rackner, MD, a surgeon and clinical faculty member at the University of Washington School of Medicine. Rackner is now a full-time patient advocate, author, speaker, and consultant.

“Begin a handwashing program at the facility,” she suggests. “Let the patients know that handwashing is to be expected from all healthcare members. Encourage patients to remind doctors and nurses to wash their hands before they examine them, should they forget. I do think coaching the patients is an idea that’s appropriate for the ambulatory surgical setting. After all, if the patient’s wound is contaminated by the person who takes off the surgical dressing, the infection is still called a post-operative infection! The wash hands program could be reinforced with both patients and staff at every stage of the process — at check in, and during post-operative check-out procedures.”

Constructing the Facility Efficiently

Tim Schmida, AIA, a healthcare architect at Burt Hill, concurs, “It has long been known that the best way to reduce or keep low the risk of nosocomial infection is through the studious practice of handwashing. So the thoughtful placement of handwashing facilities is critical. The sinks have to be convenient for staff use, and the policies and procedures of the ASC need to be explicit in this. The right kind of air, the right kind of distribution, and the right kind of finishes all help. But in the end, it is the care of the staff that is the single most influential factor in low infection rates.”

Pick Your Battles

Certain pathogens of concern require more attention, points out David H. Persing, MD, PhD, chief medical and technology officer at Cepheid, which develops, manufactures, and markets fully-integrated systems that perform genetic analysis, including DNA and RNA analysis. “Methicillin-resistant Staphylococcus aureus (MRSA) has been historically associated with hospitals, hospital staff, and hospitalized carriers,” he begins. “Ambulatory surgery patients are probably at lower risk of being carriers because they are in general younger and have not been hospitalized previously. That may all change with (community-acquired) CA-MRSA. Carriers tend to be younger and have no previous hospitalization history.

“Patients entering the operating room carrying nosocomial infections like MRSA are at a greatly increased risk for surgical site infection,” he adds. “Identifying carriers, isolating them, and administering targeted antibiotics are effective methods to stop the spread of MRSA and reduce surgical site infection rates. (The Netherlands, Sweden, and Denmark eliminated MRSA from their hospitals with stringent surveillance and isolation programs).”

Time, he observes, is critical, especially in the ambulatory setting, when patients are actually in the facility for such a short time. “A single, unidentified MRSA carrier could result in the infection of many other patients by spreading bacteria onto bed rails, door knobs, linens, etc.

“Even with medical technology advances, the risks of surgical site infection complication and infection transmission within the ambulatory surgical environment are the same as in procedures performed on inpatients,” says Jean Fleming, RN, MPM, CIC, infection prevention education manager at Professional Disposables International (PDI). “The risks in this setting are minimal primarily because the patients are more likely to be healthier than those treated in inpatient settings and the length of time a patient spends in this setting is shorter in duration. However, patients and their family members with undiagnosed or unknown communicable disease are often clustered in a common waiting room, preoperative holding area, and post-operative recovery area. This poses a risk for potential communicable disease exposure (antibiotic- resistant organisms, common colds, and other viruses) to healthcare workers, other patients, and family members.”

Good hand hygiene to reduce infection transmission is crucial, she points out, and can be made easier with the use of waterless alcohol-based hand products. “In addition to having an alcohol-based hand product available for patients, family members, and healthcare workers, environmental cleanliness within the ambulatory surgery center plays a critical part in preventing infection transmission,” she adds. “Because of the high volume of patients and the use of shared patient equipment such as blood pressure cuffs, stethoscopes, IV poles, stretchers, beds, and heart monitors, these items need to be cleaned between patient use. Healthcare workers need products that are convenient to use, that are fast-acting to kill common pathogens in the environment, and that meet with regulatory requirements for healthcare facilities.”

Proper skin preparation of the surgical site before the incision is also crucial. “A variety of agents are available for patient’s skin preparation. Povidone-iodine and chlorhexidine gluconate (CHG) are the most commonly used agents,” Fleming points out. “A new 3.15 percent CHG and 70 percent alcohol product has been recently introduced. The CHG formulation reduces skin microflora more effectively and has a better residual activity than povidone-iodine after a single application.”

Antimicrobial Dressings

At the 2006 annual meeting of the Society for Healthcare Epidemiology of America (SHEA), a five-year retrospective study of antimicrobial dressings (AMDs) was presented. The study, conducted at the Nebraska Methodist Hospital in Omaha, Neb., covered nearly 2,000 vascular procedures, in which the efficacy of AMDs was tested.

In the study, “The Reduction of Vascular Surgical Site Infections With the Use of Antimicrobial Gauze Dressing,” “Third spacing or edema at the incision site was leading to separation of wound margins. This wound separation was hypothesized to facilitate bacterial invasion, from local colonizing bacteria, into the wound. Porous gauze dressings were used on vascular surgical wounds due to low cost and their absorption capability. Studies indicated that when gauze dressings became wet, such as with sanguineous or serous drainage, bacterial migration into the wound was promoted,” write the authors.

The hospital had implemented the majority of the CDC’s evidence-based guidelines for preventing SSIs. “Special attention was given to the antiseptic shower/bath (the night before and the morning of surgery using CHG) and pre-operative antimicrobial prophylaxis, including preferred agent, dosing according to body mass index and administration within 60 minutes of incision. The guidelines for postoperative incision care that recommended sterile gauze dressings were being practiced. However, vascular wounds closed through primary intention, which then became infected, were commonly associated with postoperative third spacing and edema. The latter led to incision separation and drainage. The sterile gauze dressings were identified as porous structures, and especially after becoming moist, would not be a barrier to bacterial invasion. It was hypothesized that a woven gauze dressing containing an antimicrobial agent would prevent bacterial migration and allow the gauze to become a bacterial barrier. One available dressing — KERLIX®AMD™ gauze dressing, Tyco Healthcare Group — is impregnated with 0.2 percent polyhexamethylene biguanide (PHMB). PHMB is a broad spectrum antimicrobial agent that leads to microbial cytoplasm membrane damage, is nonvolatile, and has low mammalian toxicity.

The surgical team applied KERLIX gauze impregnated with 0.2 percent PHMB after incision closure on all vascular patients. The PHMB dressings were continued until the surgeon discontinued the dressings or the patient was discharged.

The results of the study showed that “applying a PHMB antimicrobial dressing on vascular surgical wounds was associated with decreased SSI rates in CDC NNIS risk index category 1 (4.6 percent to 0.4 percent). As an intervention, the substitute of the PHMB dressings for the non-antimicrobial dressings was associated with an estimated gross savings of $876, 176 in the five-year timeframe for all vascular surgical procedures,” the authors conclude.

Another possibility for an antimicrobial dressing is the ACTICOAT™ (with SILCRYST ™ Nanocrystals) nanocrystalline silver-based dressing, points out Karen L. Winn, RN, MSN, ARNP, medical education manager at Smith & Nephew.

“Most of the time, obviously, the best practice is keeping the incision clean and dry and following normal infection control policies and procedures,” says Winn. “ACTICOAT is a barrier dressing; it is meant to be placed on the wound and protects it from bacterial invasion as well as killing whatever bacteria may be present there.”

Usually, she explains, the patient will have some type of cover dressing on top of the antimicrobial dressing to absorb any drainage from the post-operative site, and to keep the ACTICOAT in place. If the patient were changing the dressing himself at home, he would put on a new piece of ACTICOAT, which is moistened with sterile water, and then cover it with the secondary dressing.

“When dealing with different clinics, we suggest that they follow their own protocol (for secondary dressings), so the dressing could be a transparent film dressing or it could be some type of foam dressing, for example,” Winn says. “The only thing contraindicated against ACTICOAT would be an enzymatic ointment or petroleum-based ointment.”

Keep the Future Patient Cohort in Mind

“ASCs are the ever-growing centers for this century, as we are being challenged by baby boomers. They are a very dynamic group that does not want to be constrained to a bed, so that’s where we’re going to see infection control issues. How do we send them home and provide for the caregivers to care for them?” queries Cynthia Crosby, vice president of clinical affairs at Medi-Flex.

“One of the issues cropping up between inpatient and ambulatory is clipping vs. shaving. If you have to remove hair from a surgical site, clipping is the preference because of reducing the microabrasions to the skin surface. Another issue is glucose monitoring. Controlling the glucose levels has definitely been shown — not prior to — but during and post-care, to reduce surgical site infections.”

Another issue, Crosby says, is smoking cessation, as the increased oxygenation from quitting smoking assists with oxygen absorption within tissues and thereby speeds wound healing. “I know a surgeon who operates at both Vanderbilt University and within a surgery center. He will not operate on anybody who does not sign a contract on smoking cessation. [The topic of oxygenation] is kind of controversial, but oxygenation levels in some clinical situations — where you’re running at 100 percent2 — have shown a decrease in SSIs. Some recent clinicals oppose that, or say that it really doesn’t matter, but it’s something we’re looking at.

“A further issue is normothermia, looking at the patients’ core body temperatures. We found that patients who are kept in holding areas in heating blankets before an operation have shown a decrease in SSIs,” she says.

An additional issue is pre-operative showering and bathing protocols. “The patient is sent home with a bottle of Hibiclens or antibacterial soap, or is handed little unit dose bottles for pre-shower protocols, for 24 hours prior or 48 hours prior,” Crosby adds. “They do a one- or two-shower system before coming into the facility before the surgery. Pre-op showers were pretty well recognized in the late 1980s to reduce SSIs, and got a recommendation in the SSI guidelines.

I believe the recommendation was a 1B, which is ‘highly suggestive but not overwhelming clinical evidence’. But even at Mayo and Johns Hopkins and other leading facilities, they are now reinstituting and re-implementing a pre-operative shower or bath protocol with an antimicrobial solution, which is usually chlorhexidine.”

The final issue, she says, is the timing of prophylactic antibiotics. “For the longest time, they weren’t being given within the one-hour time frame, so they were being given too far out, or they weren’t given until the initial incision,” says Crosby. “If you give them 30 to 45 minutes before the incision, you reduce SSIs. A lot of facilities are now giving the responsibility of pre-operative prophylactic antibiotics to be delivered by the anesthesia groups, because the anesthesia groups are in there placing lines, getting the patient intubated, and getting them ready for the surgical procedure.”