There are few issues that can compromise a patient outcome as severely as a nosocomial infection. This complication may manifest as a mild and annoying cellulitis or as a severe and life-threatening surgical site infection. It has the potential to compromise and even take the life of any individual undergoing surgery. Although the threat of surgical site infection remains ever present, an emerging paradigm shift of surgical site infection prevention and control is evolving.
In the 2001 assessment of the current state of infection in surgical procedures in the United States, the Centers for Disease Control and Prevention (CDC) estimated that 22% of all health-care-associated infections were surgical site infections. Approximately 290,000 surgical site infections occurred annually in the United States, resulting in $1 billion to $10 billion in direct and indirect medical costs. Approximately 8000 patient deaths were associated with these infections. One of the most heavily represented procedure types in the surgical site infection data was orthopaedic procedures.
According to unpublished CDC data, an estimated 14 million operative procedures in the United States were reported to the National Healthcare Safety Network (NHSN) in 2002. Surgical site infections were the second most common type of health-care-associated infection, accounting for 17% of all such infections among hospitalized patients. The proportion was similar in data reported to the NHSN by hospitals in 2006 to 2008, and the overall rate of surgical site infections was 1.9%1.
Nevertheless, in spite of increasing national scrutiny and public reporting of surgical site infection rates, the 1999 CDC Guideline for Prevention of Surgical Site Infection2 only provides the following evidenced-based guidelines:
“7. Require patients to shower or bathe with an antiseptic agent on at least the night before the operative day. Category IB
8. Thoroughly wash and clean at and around the incision site to remove gross contamination before performing antiseptic skin preparation. Category IB
9. Use an appropriate antiseptic agent for skin preparation (Table 6). Category IB
10. Apply preoperative antiseptic skin preparation in concentric circles moving toward the periphery. The prepared area must be large enough to extend the incision or create new incisions or drain sites, if necessary. Category II”
Wound contamination predominantly occurs secondary to transfer of bacteria from adjacent skin into the wound. Because of the variety among surgical wounds (wet or dry, with different bacterial flora depending on location), an ideal universal skin preparation for all surgical sites and procedures may not be found. Skin can never really be disinfected before surgery; colony counts can only be reduced. Surgical site infection risk data from well-controlled, procedure-specific studies are lacking, and a great number of surgeons consequently use incise drapes to mechanically block all bacteria from transfer into a surgical wound.
Skin preparations and incise drapes have been controversial for decades, and yet they are commonly used in a variety of different surgical procedures and disciplines. They have been shown to reduce postoperative wound infection and contamination, as measured by positive cultures from skin, in critical care, obstetrics, high-risk surgeries, and prolonged surgeries.
Skin preparations based on chlorhexidine gluconate (CHG) or iodine in conjunction with isopropyl alcohol (IPA) are commonly used during surgery. Because of the increase in the number of different skin preparations and different incise drapes currently available for use in clinical practice, it is important to know whether use of a particular skin preparation has an effect on adhesion of a skin drape that is used in conjunction with it. This study sought to determine the effect of the type of skin preparation on the adhesion of various incise drapes to the skin in a simulated wet saline solution environment.
It should be specifically noted that there is no skin preparation product, with or without the use of an incise drape, that has been definitively shown to reduce surgical site infections in orthopaedics in a prospective randomized trial. Ideally, such a trial would include a large sample of patients who are stratified according to surgical site infection risk, comorbidities, length of surgery, and procedure type.
Current literature suggests that chlorhexidine gluconate is superior to povidone-iodine for preoperative antisepsis, although some of the studies have been criticized because no neutralization agent was used prior to obtaining cultures of residual bacterial from treated skin surfaces. Because of this literature, some surgeons have begun choosing chlorhexidine gluconate solution in an effort to capitalize on this superior killing power. However, many surgeons use it prior to applying an incise drape. Data regarding the application of an incise drape on skin prepared with chlorhexidine gluconate are almost completely lacking.
Many surgeons choose to use surgical incise drapes on prepared surgical sites for added protection on the basis of the common-sense belief that bacteria mechanically trapped beneath an incise drape are less likely to migrate to the wound and create a surgical site infection. By design, an incise drape with a pressure-sensitive adhesive adheres to the skin and provides a sterile barrier to bacteria from the beginning of a surgical procedure. Since surgical incise drapes were first described forty years ago, there have been conflicting conclusions regarding their value with regard to reduction of surgical site infections3-5.
Drape lift or drape pull-back from the wound edge may allow skin organisms to contaminate the wound. In one laboratory study, it was shown that bacteria did not multiply under a plastic adhesive drape within the time interval studied and that lateral migration of bacteria did not occur6. Alexander et al.3 concluded that separation of incise drapes from the skin was associated with a sixfold increase in the infection rate compared with procedures in which the incise drape did not lift.
It would be desirable to obtain clinical evidence from a prospective randomized controlled trial to validate the use of skin preparation and incise drapes for reduction of surgical site infections. However, such a study, duly stratified according to surgical site infection risk, comorbidities, or length of surgery, may not be practical to achieve for clean or clean-contaminated wound classifications in a surgical specialty such as orthopaedics. To demonstrate that an intervention reduces the infection rate by one-fourth in procedures with an infection rate of 1%, 44,000 cases would be needed in order to have an 80% probability of obtaining a statistically significant result. In addition, for surgeons who have been using incise drapes to provide protection in their clinical practices, excluding the use of incise drapes on patients in a clinical study would represent a deviation from their standard of care, which many surgeons would be unwilling to do.
Because a few studies have shown that drape lift is associated with increased contamination of the wound secondary to the exposure of skin under the drape, the question that Grove and Eyberg pose regarding which skin preparation is likely to result in the least amount of drape lift is relevant to current orthopaedic practices. Their data provide baseline information regarding the performance characteristics of a number of skin preparations and incise drapes that will be required for current clinical use as well as in a larger randomized controlled trial of wound contamination from adjacent skin.