Surgical Site Infections: Risk Factors and Prevention Strategies
by the WoundSource Editors
Of the millions of surgical procedures performed annually, most surgical site wounds heal without complications. Surgical site infections (SSIs) are common complications that may occur after surgery, and that may delay healing, therefore increasing the cost of care.1
SSIs are the most common and costly hospital-acquired infections, at approximately 20% of all hospital-acquired infections and 38% of all post-operative complications.2 This equates to approximately 160,000 to 300,000 SSIs per year in the United States.3
Increases in hospital length of stay associated with SSIs range from 7-11 additional days. Patients with SSIs have a 2 to 11 times higher risk of death, and approximately 77% of deaths in patients with SSIs are directly related to those SSIs. Depending on the type of surgical procedure and type of infecting pathogen, the financial impact of SSIs is approximately $10 billion annually.
Understanding the incidence, along with the clinical and financial impact of SSIs, is of critical importance to patients, providers, and health care facilities. This is especially true for health care facilities, which must make informed decisions to allocate resources appropriately.
SSIs also have been deemed a never event since a 2008 ruling by the Centers for Medicare & Medicaid Services (CMS), and reimbursement is heavily affected by SSI rates.4 This issue is made even more difficult because there are currently no national surveillance systems to determine the actual number of common hospital-acquired infections.
Despite the evidence that surveillance of facility infection rates can be cost-effective, few hospitals have dedicated surveillance and feedback programs. Therefore, it is also difficult to determine the actual economic burden or to appreciate the savings afforded by implementation of effective prevention strategies.
Risk Factors for Surgical Site Infections
The 2017 Centers for Disease Control and Prevention (CDC) guidelines for prevention of SSIs defines these infections as "infections of the incision or organ or space that occur after surgery."5
Although most SSIs occur after discharge, there have not been many studies completed, and data are limited. A study by the American College of Surgeons, via the American College of Surgeons National Surgical Quality Improvement Program, of 49,817 operative cases identified an extensive array of risk factors. These risk factors included totally dependent functional status, obesity, complicated emergency surgery, prolonged surgical duration, chronic obstructive pulmonary disease and other respiratory conditions, diabetes, smoking, coronary artery disease, peripheral vascular disease or limb ischemia, hypertension, bleeding disorders, renal disease, preoperative sepsis, and female sex.2
Another retrospective study performed as part of the Veterans Affairs Surgical Quality Improvement Program, which included 136 Veterans Affairs hospitals, was conducted to identify risk factors associated with SSIs.6 The study population consisted of patients from the following categories: neurosurgery, urology, podiatry, otolaryngology, general surgery, orthopedic surgery, plastic surgery, thoracic surgery, vascular surgery, cardiac coronary artery bypass grafting, and cardiac valve or other surgical specialties.
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During the study, 354,528 surgical procedures were conducted, and of those 6,538 patients or 1.8% developed SSIs within 30 days. Although the rates varied among specialties, the infection rates were higher in emergency procedures, procedures with long operative duration, and more complex procedures. Other factors identified included dyspnea, open wound infections, more severe wound classification, ascites, bleeding disorders, chemotherapy, smoking, chronic obstructive pulmonary disease, radiation therapy, steroid use for chronic conditions, and weight loss.
Additionally, the emergence of antimicrobial-resistant organisms is compounding the problem and increasing both the cost and the challenge of dealing with them.5
Prevention Strategies for Surgical Site Infections
The economic and human burden of treating SSIs is complex and increases every year, as does the number of surgical procedures for patients with increasingly complex comorbidities. Approximately half of these SSIs could be preventable with the implementation of evidence-based strategies.
The CDC5 outlined strategies to aid in the prevention of SSIs that include the following:
- Shower or bathe patients before surgery with soap (antimicrobial or non-antimicrobial or antiseptic agent) at least the night before surgery.
- Administer antimicrobial prophylaxis only when indicated based on published clinical practice guidelines and timed such that the agents' bactericidal concentration is established in the serum and tissues upon incision.
- Antimicrobial prophylaxis should be administered before skin incision in cesarean section procedures.
- Operating room skin preparation should be performed using an alcohol-based agent unless contraindicated.
- For clean and clean-contaminated procedures, additional prophylactic antimicrobial agent doses should not be administered after the surgical incision is closed in the operating room, even in the presence of a drain.
- Topical antimicrobial agents should not be applied to the surgical incision.
- Glycemic control should be implemented using blood glucose target levels less than 200mg/dL during surgical procedures.
- Maintain normothermia in all patients undergoing surgical procedure.
- Increased fraction of inspired oxygen should be administered during surgery and after extubation in the immediate post-operative period for patients with normal pulmonary function who are undergoing general anesthesia with endotracheal intubation.
- Blood transfusion products should not be withheld from surgical patients as a means of preventing SSIs.
Education regarding these prevention strategies must be interdisciplinary and is essential to appropriate implementation and adoption into everyday practice. This will take guidance from physicians, nurses, and senior leadership to affect SSI rates positively. The education content must have an evidence-based focus and include the continuum of care. Senior leadership should also place emphasis on the value and benefits of SSI reduction, including the patient and fiscal outcomes.3
1. Jenks PJ, Laurent M, McQuarry S, Watkins R. Clinical and economic burden of surgical site infection (SSI) and predicted financial consequences of elimination of SSI from an English hospital. J Hosp Infect. 2014;86(1):24-33.
2. Wiseman JT, Fernandez-Taylor S, Barnes M, et al. Predictors of surgical site infection after hospital discharge in patients undergoing major vascular surgery. J Vasc Surg. 2015;62(4):1023-31.
3. Anderson DJ, Podgorny K, Berríos-Torres SI, et al. Strategies to prevent surgical site infections in acute care hospitals: 2014 update. Infect. Control Hosp Epidemiol. 2014;35(6):605-27. doi: 10.1086/676022.
4. Daniels AH, Kawaguchi S, Contag AG, et al. Hospital charges associated with "never events": comparison of anterior cervical discectomy and fusion, posterior lumbar interbody fusion, and lumbar laminectomy to total joint arthroplasty. J Neurosurg Spine. 2016;25(2):165-9. doi: 10.3171/2015.11.SPINE15776.
5. Berríos-Torres SI, Umscheid CA, Bratzler DW, et al. Centers for Disease Control and Prevention guideline for the prevention of surgical site infection. JAMA. 2017;152(8):784-91. doi:10.1001/jamasurg.2017.0904.
6. Li X, Nylander W, Smith T, Han S, Gunnar W. (2018). Risk factors and predictive model development of thirty-day post-operative surgical site infection in the Veterans Administration surgical population. Surg Infect(Larchmt). 2018 Feb 1 [Epub ahead of print]. doi: 10.1089/sur.2017.283.
The views and opinions expressed in this blog are solely those of the author, and do not represent the views of WoundSource, Kestrel Health Information, Inc., its affiliates, or subsidiary companies.