Prolonged Therapy Is Not Associated with Delayed Identification of Recurrent Intra-Abdominal Infection

The Study to Optimize Peritoneal Infection Therapy (STOP-IT) Trial identified an association between prolonged antibiotic therapy and delayed identification of recurrent intra-abdominal infection (IAI). However, this association has not been observed in other studies. The purpose of this study was to evaluate the association between recurrent IAIs and the duration of antibiotic agents. Adult patients from 2016 to 2020 who underwent a source control procedure for a colon-related complicated IAI were identified. Patients not meeting the inclusion criteria were excluded. Demographics, comorbidities, post-operative antibiotic duration, and presence of secondary intra-abdominal infection were recorded. The primary outcome was the time to identification of secondary IAI. Delayed identification of recurrent infection was identified as 10 or more days following source control procedure. Statistical analysis using χ², Fisher exact, and Wilcoxon rank sum were used where appropriate. Seventy-six of the patients identified met inclusion criteria, and 17 (22.4%) of those patients had a recurrent IAI. Patients with recurrent infections were slightly younger (64 vs. 60 years; p = 0.01) and had lower rates of pre-operative anticoagulation (50.8% vs. 17.6%). There were no differences in the initial length of antibiotic therapy after source control between the recurrent infection and non-recurrent groups (p = 0.6). There was a difference in total days of antibiotic use between the two groups, with the recurrent infection group averaging 10 more days of antibiotic use than the non-recurrence group (p < 0.0001). In those patients with a recurrence, there were no differences in median days to identification (9 vs. 11.5 days; p = 0.29) or the rate of those with delayed identification of recurrent infection (44.4% vs. 75%; p = 0.33). Similar to the STOP-IT Trial we failed to identify an association between the duration of post-operative antibiotic agents and recurrent infection. However, we further failed to identify an association between the prolonged post-operative courses and the timing of identification of the recurrent infection. Further evaluation is needed to determine if prolonged therapy delays the identification of recurrent infection.