Risk Factors for Surgical Site Infection

Background: As many as 5% of patients undergoing surgery develop surgical site infections (SSIs), which may cause much morbidity and may sometimes be fatal. Treating SSIs imposes a substantial strain on the financial resources of the health care system. Methods: Review of current practice and guidelines. Results: Important patient-related factors for SSI include existing infection, low serum albumin concentration, older age, obesity, smoking, diabetes mellitus, and ischemia secondary to vascular disease or irradiation. Surgical risk factors include prolonged procedures and inadequacies in either the surgical scrub or the antiseptic preparation of the skin. Physiological states that increase the risk of SSI include trauma, shock, blood transfusion, hypothermia, hypoxia, and hyperglycemia. Parameters that may be associated independently with an increased risk of SSI, and that may predict infection, include abdominal surgery, a contaminated or dirty operation, and more than three diagnoses at the time of discharge. The major sources of infection are microorganisms on the patient's skin and, less often, the alimentary tract or female genital tract. The organism most often isolated is Staphylococcus aureus, which often is resistant to methicillin. Antibiotic-resistant bacteria are a continuing and increasing problem. Conclusions: A wide range of patient-related, surgery-related, and physiological factors heighten the risk of SSI.