Impact of Vancomycin Surgical Antibiotic Prophylaxis on the Development of Methicillin-Sensitive Staphylococcus aureus Surgical Site Infections

In Brief Objective: To compare risks for developing surgical site infection (SSI) due to Staphylococcus aureus when vancomycin is used for antibiotic prophylaxis with risks when a β-lactam antibiotic is administered for prophylaxis. Background: Vancomycin is often used as surgical antibiotic prophylaxis for major surgery. In nonsurgical populations, there is evidence that vancomycin is less effective for prevention and treatment of methicillin-sensitive Staphylococcus aureus (MSSA) infections. Since 2002, the Victorian Healthcare Associated Surveillance System (VICNISS) has used standardized methods for infection surveillance in Australia, including any prophylactic antibiotic agent administered before surgical procedures. Methods: Surveillance records were obtained for patients undergoing 4 clean surgical procedures during the period of November 2002 to June 2009. Logistic regression analysis was used to examine risk factors for infection, including age, procedure duration, American Society of Anesthesiologists score, and choice and timing of antibiotic prophylaxis. Results: The data set consisted of 22,549 procedures, including cardiac bypass and hip and knee arthroplasty procedures. Vancomycin prophylaxis was administered in 1610 cases and a β-lactam antibiotic for 20,939 cases. A total of 754 SSIs were recorded. The most frequent pathogens were MSSA, methicillin-resistant Staphylococcus aureus, and Pseudomonas species. The adjusted odds ratio (OR) for an SSI with MSSA was 2.79, where vancomycin prophylaxis was administered (P < 0.001). For methicillin-resistant Staphylococcus aureus infection, the adjusted OR for vancomycin was 0.44 (P = 0.05), whereas for Pseudomonas infection, it was 0.96 (P = 0.95). Conclusions: In a large Australian study population, prophylaxis with vancomycin was found to be associated with an increased risk of SSI due to MSSA when compared with prophylaxis with a β-lactam antibiotic. Given the potential for poorer surgical outcomes in the setting of indiscriminate prophylactic vancomycin use, measures to improve adherence to guidelines for restricted administration of prophylactic vancomycin are supported. Although vancomycin is commonly used for surgical antibiotic prophylaxis, evidence in nonsurgical populations suggests that this agent is not as effective as β-lactam antistaphylococcal antibiotics for infections due to methicillin-sensitive Staphylococcus aureus. In this study, infection risks for developing staphylococcal infections when vancomycin was used for prophylaxis were compared with risks when β-lactam antibiotics were administered.