905 - Surgical Site Infections Following Colon Surgery in a Large Network of Community Hospitals

Background: Colon surgeries are commonly performed, and surgical site infections (SSIs) following these procedures are routinely reported to the National Healthcare Safety Network (NHSN). However, the impact of infections present at the time of surgery (PATOS) and emergent surgeries on the epidemiology of colon surgery SSIs has not been well described.

Methods: We retrospectively analyzed prospectively collected data on complex (i.e., deep incisional or organ space) SSIs following colon surgery performed at 34 community hospitals in the southeastern United States from January 2015 to June 2019. We excluded SSIs categorized as PATOS. We then stratified colon surgery SSI rates according to age, sex, body mass index (BMI), operation duration, diabetes diagnosis, American Society of Anesthesiologists (ASA) physical status, wound class, emergent procedure, endoscopic procedure, and hospital colon surgery volume. Finally, we explored effect measure modification of emergent surgery and open surgery on hospital volume using log-binomial modeling and tests of homogeneity.

Results: A total of 722 complex SSIs occurred following 28,642 colon surgeries (prevalence rate [PR], 2.52 per 100 procedures). After PATOS SSIs were excluded, 545 complex SSIs remained (PR 1.90 per 100 procedures). Risk factor analysis revealed that age < 75 years and operation time > 75^th percentile (188 minutes) during the 5-year study period) significantly increased risk of SSI (Table 1). The most common pathogens that caused SSIs in this study cohort were Escherichia coli, Enterococcus, and Klebsiella. (Table 2) 105 (19%) SSIs were culture-negative and 378 (69%) of the SSIs were polymicrobial. We defined hospital volume as high ( >500 procedures in the 5-year period) based on the median hospital volume in the dataset. No significant effect measure modification occurred between hospital volume and either laparoscopic surgery or emergent surgery (Table 3).Table 1: Characteristics of patients who underwent colon surgery from January 2015 to June 2018 in 34 community hospitals.
Table 2: Count and frequency of pathogens that caused complex surgical site infections after colon surgery
Table 3: Colon surgery complex surgical site infection rates, stratified by emergent, elective, open, and laparoscopic procedures and hospital colon surgery volume


Conclusion: In our cohort, we found that one-fourth of colon surgery SSIs were categorized as PATOS, which are no longer publicly reported to the Centers for Medicare & Medicaid Services. While most SSI literature describes higher volume hospitals having lower SSI rates, high colon surgery volume was associated with increased SSI rates in our community hospital cohort.