719. Clinical Outcomes of Single versus Double Anaerobic Coverage for Intra-abdominal Infections

Abstract

Background Double anaerobic coverage (DAC) is often used for intra-abdominal infections (IAIs) post-operatively. The primary objective of the study was evaluating length of hospital stay (LOS), in-hospital post-operative complications, and re-admission within 30 days of discharge due to post-operative complications in patients who received piperacillin/tazobactam plus metronidazole versus piperacillin/tazobactam for IAIs post-operatively. The secondary objective was comparing in-hospital mortality and hospital-acquired Clostridioides difficile infections (CDI) between the two groups. Methods This was a retrospective, cohort study including adults with surgically managed IAIs at an urban community hospital between January 1, 2016 and June 30, 2019. The following data were collected: age, sex, body mass index, comorbidities, Charlson Comorbidity Index (CCI), 5-day post-operative body temperature, American Society of Anesthesiologists (ASA) pre-operative assessment score, surgical wound classification, and IAI diagnosis. Multivariate analysis and aggregate resampling of the sampling distribution were conducted. An alpha of < 0.05 was considered statistically significant. Results Out of 163 patients, 96 patients received piperacillin/tazobactam plus metronidazole and 67 patients received piperacillin/tazobactam. The patients who received DAC were sicker with higher CCI (p=0.021) and 5-day post-operative body temperature (p=0.013). They were also at a higher risk for surgical site infections (p=0.002). Double anaerobic coverage was more often used for acute cholecystitis (p=0.0001) and gastrointestinal perforations (< 0.0001). After adjusting for these variables, DAC was associated with longer LOS (median 9 days vs. 4 days, p< 0.0001) and in-hospital post-operative complications (23% vs. 9%, p< 0.0001). There were more re-admissions within 30 days of discharge due to post-operative complications in the single anaerobic coverage group (4% vs. 1%, p=< 0.0001). In-hospital mortality (4% vs. 0%) and hospital-acquired CDI (1% vs. 0%) were only observed in DAC group. Conclusion Double anaerobic coverage was associated with no clinical benefit in surgically managed IAIs and in some cases may produce worse outcomes. Disclosures All Authors: No reported disclosures