881 - Efficacy of Antibiotic Prophylaxis with Vancomycin in Cardiothoracic Surgery

Background: Due to the high incidence of methicillin-resistant Staphylococcus aureus (MRSA) at the Detroit Medical Center, vancomycin is now routinely part of the prophylaxis regimen for cardiothoracic (CT) surgery. The study aims to compare the rate and types of surgical site infections (SSIs) when vancomycin is added to cefazolin for CT surgery compared to cefazolin alone.

Methods: This was a retrospective cohort study conducted at two university-affiliated hospitals. Patients who underwent CT surgery between January 2008 and August 2017 and had a readmission for SSI within 90 days of procedure were included. Patients who received cefazolin were compared to patients who received both cefazolin and vancomycin for CT surgery prophylaxis. The primary outcome was incidence of SSIs within 90 days of surgery as defined by the Centers for Disease Control and National Healthcare Safety Network.

Results: Out of 828 patients who underwent CT surgeries, there were 32 patients readmitted within 90 days for SSI. SSI occurred in 4.7% of patients who received cefazolin monotherapy, and 2.4% of patients who received both cefazolin and vancomycin (p=0.095). There was no discernible difference in types of SSI between groups. Pathogens were isolated in 78% of SSIs, with 75% Gram-positive and 19% Gram-negative organisms. SSIs resulted in an average 9.8 days in the hospital and 28.9 days of antibiotic therapy, and led to a total of 15 additional procedures.

Conclusion: Vancomycin added to cefazolin for prophylaxis in CT surgery resulted in lower incidence of SSI, however the difference was not statistically significant.