SURGICAL-SITE INFECTION (SSI) continues to pose a major problem for many surgery patients. Experts place the number of healthcare-acquired infections (HAI) in the range of 875,000 to 3.5 million per year.1 Infection due to medical care is associated with 9.58 more days in the hospital, an increased cost of $38,656, and an increase in mortality of 4.31%.2 SSI accounts for more than 30% of HAI.3,4
At one time, SSIs were considered a normal stage of healing for surgical patients.5 As education progressed, we discovered that aseptic technique helps decrease infection incidence, thus lowering mortality rates of surgical patients. Improvements in infection control practices-including sterilization methods, operating room (OR) ventilation, surgical technique, and antibiotic availability-decreased the incidence of SSI, but don't eradicate the problem. Why? The emergence of antibiotic resistant pathogens and increasing numbers of elderly patients who are debilitated or immunocompromised have increased the risk of SSI.6
Four variables determine whether a surgical wound will heal uneventfully or become an SSI. The first variable involves the amount of bacteria that enters the wound area, either from the air in the OR or from surgical instruments. The largest amount of bacteria enters the wound when the surgical procedure involves an area of the body that's heavily colonized by bacteria, such as the bowel.
The virulence of the bacteria is a second variable. The more virulent the bacteria, the more likely an infection will occur. The microenvironment of the wound is a third variable that can determine an SSI. Necrotic tissue can serve to protect bacteria and aid in avoidance of phagocytic defenses at the wound site, and foreign bodies, such as braided suture material, can harbor microbes and promote infection.
Integrity of host defenses is the fourth and last variable. Some patients have more effective intrinsic responses to invasion of bacteria or other microbes. Impairment of host responses, such as shock and hypoxemia related to trauma, chronic illnesses, malnutrition, hypothermia and hyperglycemia, is related to increased rates of SSIs.7 Wounds were originally classified into four separate classes of procedures with an infection rate attached to each. (See Table 1.)
To standardize the diagnosis of SSI, the National Nosocomial Infections Surveillance (NNIS) system developed criteria to define SSIs as: superficial incisional, deep incisional, and organ/space. When used in combination with the NNIS Risk Index, this information gives accurate information about SSI rates and severity.8 (See Table 2.)
Response
In 1999, the Centers for Disease Control and Prevention (CDC) published guidelines for prevention of SSI that included preoperative recommendations on hair removal, glycemic control, hand and forearm preparation, and antimicrobial prophylaxis, as well as other intraoperative and postoperative recommendations. One recommendation was that hair only be removed when necessary. If removed, the hair should be clipped immediately before the procedure. It was strongly recommended that hyperglycemia should be avoided in the diabetic patient during the perioperative period, and blood glucose levels adequately controlled.9
The Centers for Medicare & Medicaid Services developed a collaborative initiative in December 2001 to work on the topic of SSI prevention. The initiative, called Surgical Care Improvement Project (SCIP), has an ultimate goal of nationally reducing the incidence of surgical complications by 25% by the year 2010 and promoting universal use of evidence-based guidelines. This team began with a pilot project in 2003 and will work with hospitals in every state beginning this year. The pilot collected data on process measures that involved prophylactic antibiotic administration. A process measure on controlled perioperative serum glucose has been added, and measures on proper hair removal and normothermia will be tested in a selected group of patients.10
The CMS has established voluntary reporting standards, and just this year aligned its measures with those required by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO), even though time frames are different and collected data may come from different hospitals. This year those healthcare institutions that choose not to report will receive less money for services, and next year the reporting will be mandatory on those indicators.
The Institute for Healthcare Improvement (IHI), founded in 1991 to improve the lives of patients, has begun an initiative entitled 100,000 Lives Campaign.11 The intent is to save 100,000 lives between January 2005 and June 2006, using proven interventions. Preventing SSIs is part of the campaign. In a how-to guide on preventing SSIs, four identified care components are: appropriate use of prophylactic antibiotics, appropriate hair removal, maintenance of perioperative glucose control, and maintenance of perioperative normothermia.
The Agency for Healthcare Research and Quality developed patient-safety indicators, several related to infections, that are used as quality indicators and also used by some organizations as pay for performance.12 The CDC has developed seven healthcare safety challenges that include reducing targeted surgical adverse events by 50% in 5 years.13 The JCAHO has included reduction of HAI risk as a 2006 patient-safety goal.14
Treatment specifics
* Site preparation. Per the CDC, hair should be removed with electric clippers only if it interferes with the operation because the nicks associated with shaving harbor microbe growth. To best prevent SSI, clip immediately prior to surgery, and instruct the patient to avoid shaving or using depilatories the night before.The CDC also strongly recommends that patients be required to shower or bathe with an antimicrobial solution the night before surgery. The area around the incision site should be thoroughly washed and cleaned to remove gross contamination, and an appropriate antiseptic agent for skin preparation should also be used.
* Glycemic control. Diabetes is a risk factor for perioperative complications and has been related to SSIs. Glycemic control has been linked to a significant reduction in deep sternal wound infections in the patient who has open heart procedures, and associated with decreased mortality and length of stay in the intensive care unit. Experts believe that one way hyperglycemia contributes to SSI is by impairing phagocytosis, which affects the body's normal defense mechanisms.15 SSI risk is tied more to hyperglycemia than a diagnosis of diabetes mellitus.16Glucose can be controlled by use of a sliding scale protocol. Aggressive glycemic control is achieved with the use of a continuous insulin infusion. The infusion rate is adjusted using blood glucose levels based on a protocol to keep the glucose level within a certain range. The patient has to be carefully monitored because there have been incidences of hypoglycemia attributed to the treatment.17There's no evidence yet to clearly define the parameters of blood glucose levels, although blood glucose above 200 mg/dL has been associated with SSIs.18 The IHI suggests that since the best evidence for glycemic control is in the cardiovascular population, control of blood glucose levels should begin with those patients.
* Prophylactic antibiotics. The use of antimicrobial prophylaxis (AMP) refers to the short-term use of antibiotics to decrease the amount of microbes at the incision area to allow the patient's defenses to prevent an SSI. AMP is used with patients who have clean-contaminated or contaminated procedures. Patients who have a procedure that's considered "dirty" will already be on antibiotics as a treatment for infection, not prophylaxis. AMP during clean surgery is usually only initiated where bone is excised or a prosthesis is inserted.Antibiotic choice is based on safety and coverage of relevant pathogens. Recommendations from the National Surgical Infection Prevention Project include administering the antibiotic within 1 hour of incision time (2 hours with vancomycin), ending the AMP within 24 hours after the surgery, and use of an appropriate dosage based on weight or body mass index. In cesarean sections, the antibiotic is administered after the umbilical cord has been clamped. When the procedure is long and continues 2 half-lives after the initial dose, redosing of the antibiotic should occur.
The following are performance measures designated as quality indicators by the SCIP.
1. Patients received antibiotics within 1 hour before incision time (2 hours for vancomycin).
2. AMPs were used as recommended in guidelines.
3. AMPs were discontinued within 24 hours of surgery.20 In a recent study of 34,133 inpatients, only 55.7% of patients received antibiotics within 1 hour before incision, and only 40.7% of patients had AMP discontinued within 24 hours.
Nursing implications
Nurses must be aware of guidelines and practice evidence-based care. By working together with the patient and the other healthcare professionals, you can take specific steps to help decrease SSIs. SSIs continue to be a major problem for many patients. Do your part by becoming educated and remaining alert as new information for treatment and care become available.
Jan Odom-Forren is a perioperative/perianesthesia consultant in Louisville, Ky.
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