Surgical site infections following bariatric surgery in community hospitals: a weighty concern?

Although obesity is a well-known risk factor for surgical site infection (SSI), specific risk factors for SSI among obese patients undergoing bariatric surgery (BS) have not been well-defined.

We performed a prospective cohort study on patients who underwent BS at nine community hospitals in the USA between 7/1/2007 and 12/31/2008. Each patient had the following data recorded: National Nosocomial Infection Surveillance (NNIS) risk index; the choice, timing, and dose of antibiotic prophylaxis; age; body mass index; and duration of surgery. NNIS criteria were used to define SSI. Cases were detected during the post-operative hospital stay, on readmission to hospital within 30 days of the procedure and by post-discharge surveillance.

A total of 2,012 patients were included in the study. The majority of procedures were laparoscopic (82%). The overall rate of SSI was 1.4% (28/2012). Patients who received vancomycin surgical prophylaxis were more likely to develop SSI than patients who received other antibiotics (relative risk [RR] = 9.4; 95% confidence interval [CI] = 3.1-26.1; p = 0.005). More specifically, patients who received vancomycin prophylaxis as a single agent at a dose less than 2 g were more likely to develop SSI than patients who received other antibiotic regimens (RR = 7.1; 95% CI = 1.9-23.8; p = 0.035).

Inadequate dosing of vancomycin prophylaxis prior to BS is associated with increased risk of SSI. If vancomycin is used for prophylaxis, the appropriate dose should be calculated using actual bodyweight rather than lean bodyweight in accordance with Infectious Disease Society of America recommendations.