Preventing Surgical Infections

Surgical procedures are increasingly common and complex in the U.S. More than 30 million people undergo surgery each year. Surgical teams now operate in ambulatory care centers, freestanding facilities and physicians’ offices. Unfortunately, whatever the setting, some patients develop surgical-site infections (SSIs).

The true incidence of SSI is difficult to determine. It may be underestimated because of the lack of a consistent surveillance system and the development of infections after patients are discharged.

Historically, 2-4 percent of clean surgeries became infected. Edwards, et al., enumerate SSI rates for multiple procedures reported through the National Health Safety Network as ranging from less than 1 percent among low-risk patients having carotid endarterectomies or hernia repair to more than 20 percent in high-risk liver, pancreas or rectal surgeries.1

Knowledge Is Power

To prevent these infections, we need to know how many and what infections are occurring. Mandatory reporting of healthcare-acquired infections in hospitals exists in 26 states; nine states mandate reporting in ambulatory surgery centers. The Centers for Medicare and Medicaid Services will require public reporting of certain SSIs within the next 2 years.

Nonetheless, our standard of nursing care for preventing SSIs should remain the same no matter the operative setting or legislation. Nurses’ primary impetus to reduce infections is to avoid untoward effects on the patient including disfigurement, repeat surgeries and hospital admissions and added complications secondary to the treatment of the SSI.

Combating Infections Essential

Surgery interrupts the patient’s skin integrity, one of our most basic defense mechanisms. The development of an SSI depends on several factors. One is the amount and type of bacteria introduced into the wound. Bacteria may be introduced from an external source such as an accidental contamination of the sterile field. More commonly, bacteria enter the site from the patient’s own flora, especially if the operative site is heavily colonized with bacteria (e.g., the gastrointestinal tract).

The local condition of the surgical site is a second influence. Wound sites with necrotic tissue, ones that are poorly perused or have a foreign body – either implanted or because of trauma – are more likely to develop an SSI.

A third factor is the host’s defenses and coexisting conditions such as diabetes, obesity, malnutrition, tobacco use and extremes of age.2 Other treatments such as immunosuppressive therapy or prolonged hospitalization can impinge the host’s natural defenses.

The most common organisms associated with SSIs are Staphylococcus aureus and Coagulase-negative staphylococci as might be expected because of their colonization of the skin. Other causative organisms are those in the area of the operative site. For example, Enterococci and Escherichia coli are likely culprits with abdominal or genitourinary procedures. Finally, exogenous organisms may be introduced through contaminated instruments, air supply or the operating team.

Prevention Is Key

Preventive measures can directly or indirectly address bacteria that enter the wound site. In the short term, it may be difficult to control the third factor, host defenses, because it is beyond the immediate scope of the nurse. General preoperative nursing measures may enhance the host defenses through improved nutrition, glucose control, smoking cessation or treatment of a remote infection.

More specific preop interventions aim to reduce the patient’s microbial flora, for instance, by detecting MRSA colonization via surveillance cultures with subsequent decolonization with mupirocin ointment. Several centers have noted success with this method among cardiac and orthopedic cases.

Rochester General Hospital, Rochester, NY, included this as part of a bundle approach and reduced cardiac SSI rate to 0.4 percent.3 A preop shower or bath with a chlorhexidine agent is another measure to reduce skin flora.

Careful Preparation

Immediate preop care includes prepping the surgical site. If hair removal is necessary, use a clipper. Apply a skin antiseptic to the site and allow it to dry. Currently, the CDC does not specify the type of antiseptic to use, although evidence with central-line insertion has led to the use of chlorhexidine products for surgical skin prep.

Begin efforts to maintain normothermia in preop, since hypothermia can increase the risk of surgical infections. Warmed IV fluids and forced warm-air blankets with a target temperature immediately postop greater than 36ø C are good measures to practice.

The surgical team should perform hand antisepsis with antimicrobial soap or antiseptic surgical hand rub. They should don surgical attire including masks and caps. Maintaining a sterile field is mandatory; the nurse should be empowered to identify any lapses in technique.

Although the nurse is not responsible for the air-handling system, scrub and circulating nurses should have a general familiarity with temperature, humidity and air flow requirements for an operating room. This may be particularly important to monitor in non-hospital affiliated practices.

During Surgery

Two control measures are generally the responsibility of the anesthesia team. The nurse should be aware of the importance of glucose control to maintain serum glucose less than 200 mg/dL.

Prophylactic antibiotics guidelines are intended to cover the organisms likely to be encountered during a particular surgery. In addition to appropriate selection of an antibiotic, the timing of the initial antibiotic should be started within 1 hour prior to incision. Antibiotics with longer infusion times (e.g., vancomycin) may be started within 2 hours.

Several of these measures – prophylactic antibiotics, normothermia, glucose control and appropriate hair removal – are part of the Surgical Care Improvement Project, a national quality project with the goal to reduce surgical complications by 25 percent.

Adherence to these indicators is collected for

• coronary artery bypass graft;

• knee and hip arthroplasties;

• other cardiac surgery;

• colon surgery;

• hysterectomy; and

• vascular surgery.

Postop Care

Postoperative nursing care focuses on assessing the patient and promoting wound healing. The nurse should assess for signs of infection including an elevated white blood cell count, fever, redness, swelling, discharge or purulence from the site. A deep surgical wound infection may present with a change in vital signs such as hypotension.

Generally, a sterile dressing will cover the wound. Use aseptic technique to change the dressing until surgeons decide a dressing is no longer necessary. Finally, instruct the patient on wound care at home and to report any change in the character of the site to his physician.

References for this article can be accessed at Click on Resources, then References.

Barbara A. Smith is a nurse epidemiologist at St. Luke’s Hospital, New York.

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